Search

The study of the biological activity of trypsin isoforms in aqueous-organic media is of great interest to various fields of knowledge and biochemistry applications. Thus enzymatic, structural, and energetic properties of bovine β- and α-trypsin isoforms were compared in aqueous-organic media using 30 mg of each isoform. The results showed that the changes induced on the structure and activity of the same trypsin isoform occur at different concentrations. Better results for activity (ionic strength of 0.11 mol·L -1 , at 37 °C and pH 8.0) were found in 0-40% of ethanolic media in which the activity for β-trypsin was about 60% higher than ɑ-trypsin. The ethanolic system does not cause significant changes in the level of secondary structure but the β-trypsin isoform undergoes a major rearrangement. The use of until 60% (v/v) ethanol showed that β-trypsin presents a denaturation process 17% more cooperative. The organic solvent causes redistribution in the supramolecular arrangement of both isoforms: all concentrations used induced the β-trypsin molecules to rearrange into agglomerates. The ɑ-trypsin rearranges into agglomerates up to 60% (v/v) of ethanol and aggregates at 80% (v/v) of ethanol. Both isoforms keep the enzymatic activity up to 60% (v/v) of ethanol., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The endocannabinoid system is capable of modulating multiple physiological brain functions including learning and memory. Moreover, there is evidence that the processes of acquisition and consolidation have distinct biological basis. We used the cannabinoid agonist WIN 55,212-2 (WIN-2) to investigate whether chronic CB1 activation affects acquisition and consolidation differently by evaluating gene expression in the hippocampus (HIP) and prefrontal cortex (PFC). Swiss mice were treated with WIN-2 (2 mg/kg) and submitted to the Morris water maze to evaluate different aspects of memory. We observed short-term memory impairment in acquisition of the spatial task while consolidation remained unchanged. In the PFC, animals that received WIN-2 prior to the task exhibited increased expression of the 2-AG synthesis enzyme diacylglycerol lipase and decreased levels of the degradation enzyme monoacylglycerol lipase, while mice that were treated after the task for the evaluation of consolidation exhibited the opposite profile. With respect to genes related to AEA metabolism, no correlation between the molecular and behavioral data could be established. In this sense, the cognitive impairment in the acquisition promoted by WIN-2 treatment may be related to a possible increase in the concentration of 2-AG in the PFC. Overall, this study confirms the relevance of the endocannabinoid system in the modulation of cognitive processes. A better understanding of the mechanisms underlying endocannabinoids roles in cognition could provide guidance for the development of treatments to reduce the cognitive deficits caused by drug abuse., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Acute organophosphate (OP) poisoning induces well-known signs of toxicosis related to acetylcholinesterase (AChE) inhibition. However, the relationship between acute OP poisoning and the onset of psychiatric disorders remains unclear. Thus, we investigated behavioural and biochemical consequences of acute exposure to the OP chlorpyrifos in male rats and also the effectiveness of the antidotes atropine and pralidoxime on reversing these changes. A sub-lethal dose of commercial chlorpyrifos (20 mg/kg, i.p.) elicited signs of acute toxicosis during the first hours after its injection in rats. Twenty-four hours after treatment, this single dose of chlorpyrifos induced a depressive-like behaviour in the rat forced swimming test without impairing locomotor activity. At this time (24 h), chlorpyrifos decreased plasma butyrylcholinesterase (BChE) activity and hippocampal, striatal and prefrontal cortical AChE activity in rats. The behavioural and biochemical consequences of acute chlorpyrifos poisoning do not seem to be long lasting, since 30 days later they were absent. We evaluated whether these behavioural and biochemical consequences of acute chlorpyrifos treatment would be reversed by the antidotes atropine (10 mg/kg i.p.) and/or pralidoxime (40 mg/kg; i.p.) given 1 h after poisoning. Pralidoxime partially reactivated the AChE activity in the prefrontal cortex, but not in the hippocampus and striatum. Atropine attenuated the depressive-like behaviour induced by chlorpyrifos in rats. Our results suggest that acute chlorpyrifos poisoning induces a transient depressive-like behaviour possible related to hippocampal AChE inhibition. They suggest that treatment with atropine and pralidoxime seems to be insufficient to counteract all the effects of OP acute poisoning, at least in rats., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The α-trypsin isoform is a globular protein that belongs to serine-protease family and has a polypeptide chain of 223 amino acid residues, six disulfide bridges and two domains with similar structures. The effects of aqueous-organic solvent (ethanol) in different concentration on the α-trypsin structure have been investigated by spectroscopic techniques and thermodynamic data analysis. The results from spectroscopic measurements, including far-UV Circular Dichroism, UV-vis absorption spectroscopy, intrinsic tryptophan fluorescence and dynamic light scattering (DLS) suggest the formation of partially folded states, instead of aggregate states, at high ethanol concentration (>60% v/v ethanol), with little loss of secondary structure, but with significant tertiary structure changes. The thermodynamic data (T m and ΔH) suggest a loosening of intramolecular weak interactions, which reflects in a flexibility increase such that the catalytic capacity can be increased or decreased according to the ethanol concentration into the system. Overall results we suggest that in range of 0-60% v/v ethanol/buffer, α-trypsin undergoes reversible multimerization phenomena with catalytic activity. However from 60% v/v ethanol/buffer, population of folded partially states with less catalytic activity are predominant., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Crack-cocaine addiction has increasingly become a public health problem worldwide, especially in developing countries. However, no studies have focused on neurobiological mechanisms underlying the severe addiction produced by this drug, which seems to differ from powder cocaine in many aspects. This study investigated behavioural, biochemical and molecular changes in mice inhaling crack-cocaine, focusing on dopaminergic and endocannabinoid systems in the prefrontal cortex. Mice were submitted to two inhalation sessions of crack-cocaine a day (crack-cocaine group) during 11 days, meanwhile the control group had no access to the drug. We found that the crack-cocaine group exhibited hyperlocomotion and a peculiar jumping behaviour ("escape jumping"). Blood collected right after the last inhalation session revealed that the anhydroecgonine methyl ester (AEME), a specific metabolite of cocaine pyrolysis, was much more concentrated than cocaine itself in the crack-cocaine group. Most genes related to the endocannabinoid system, CB1 receptor and cannabinoid degradation enzymes were downregulated after 11-day crack-cocaine exposition. These changes may have decreased dopamine and its metabolites levels, which in turn may be related with the extreme upregulation of dopamine receptors and tyrosine hydroxylase observed in the prefrontal cortex of these animals. Our data suggest that after 11 days of crack-cocaine exposure, neuroadaptive changes towards downregulation of reinforcing mechanisms may have taken place as a result of neurochemical changes observed on dopaminergic and endocannabinoid systems. Successive changes like these have never been described in cocaine hydrochloride models before, probably because AEME is only produced by cocaine pyrolysis and this metabolite may underlie the more aggressive pattern of addiction induced by crack-cocaine., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Research has identified a strong link between stress and drug use behaviours. Also, it has been established that the prolonged use of crack cocaine stimulates emotional, cognitive, neurological and social changes. This paper explores the psychological stressors that occur from crack cocaine use and the coping mechanisms used to mitigate them. This will provide an understanding of the intricate relationship between substance use and psychological well-being. Methodology: The study is qualitative and uses a descriptive phenomenological approach. The coping circumplex model is the theoretical model that underpins the study. Data was collected through 26 face-to-face in-depth semi-structured interviews with people who use crack cocaine. Data were analysed using thematic analysis. Participants consisted of 15 males and 11 females between the ages of 24–57 years, guaranteeing multiplicity within the study sample. Results: Cravings, financial burdens, relationship breakdown and emotional /cognitive stimulation were revealed as psychological stressors. Maladaptive coping which includes self-harm, isolation, not speaking about/not dealing with emotions and using substances were adopted by study participants. Also, positive coping such as seeking help and keeping busy were adopted by study participants. Social and environmental factors such as stigma, easy accessibility of crack and flashbacks served as barriers to positive coping. Positive coping was linked to the availability and easy accessibility to social support and strong family bonds, underlining the importance of accessible support systems in managing the challenges linked with crack cocaine use. Conclusion: The challenges faced by study participants in coping with the psychological stressors linked to their crack cocaine use highlight the importance of adopting personalised and comprehensive strategies to tackle the intricate dynamics between psychological stress, coping and crack cocaine use. [ABSTRACT FROM AUTHOR]

The maintenance of extracellular Na+ and Cl- concentrations in mammals depends, at least in part, on renal function. It has been shown that neural and endocrine mechanisms regulate extracellular fluid volume and transport of electrolytes along nephrons. Studies of sex hormones and renal nerves suggested that sex hormones modulate renal function, although this relationship is not well understood in the kidney. To better understand the role of these hormones on the effects that renal nerves have on Na+ and Cl- reabsorption, we studied the effects of renal denervation and oophorectomy in female rats. Oophorectomized (OVX) rats received 17β-estradiol benzoate (OVE, 2.0 mg · kg(-1) · day(-1), sc) and progesterone (OVP, 1.7 mg · kg(-1) · day(-1), sc). We assessed Na+ and Cl- fractional excretion (FENa+ and FECl- , respectively) and renal and plasma catecholamine release concentrations. FENa+ , FECl- , water intake, urinary flow, and renal and plasma catecholamine release levels increased in OVX vs control rats. These effects were reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation did not alter FENa+ , FECl- , water intake, or urinary flow values vs controls. However, the renal catecholamine release level was decreased in the OVP (236.6 ± 36.1 ng/g) and denervated rat groups (D: 102.1 ± 15.7; ODE: 108.7 ± 23.2; ODP: 101.1 ± 22.1 ng/g). Furthermore, combining OVX + D (OD: 111.9 ± 25.4) decreased renal catecholamine release levels compared to either treatment alone. OVE normalized and OVP reduced renal catecholamine release levels, and the effects on plasma catecholamine release levels were reversed by ODE and ODP replacement in OD. These data suggest that progesterone may influence catecholamine release levels by renal innervation and that there are complex interactions among renal nerves, estrogen, and progesterone in the modulation of renal function.

Several studies have demonstrated that gonadal hormones show significant effects on the brain and signaling pathways of effector organs/cells that respond to neurotransmitters. Since little information is available concerning the impact of male and female gonadal hormones on the renal and peripheral sympathetic system, the objective of this study was to further assess whether and how the renal content and plasma concentration of catecholamines are influenced by gender and the estrous cycle in rats. To achieve this, males Wistar rats were divided into 4 groups: (i) sham (i.e., control), (ii) gonadectomized, (iii) gonadectomized and nandrolone decanoate replacement at physiological levels or (iv) gonadectomized and nandrolone decanoate replacement at high levels. Female Wistar rats were divided into 6 groups: (i) ovariectomized (OVX), (ii) estrogen replacement at physiological levels and (iii) estrogen replacement at at high levels, (iv) progesterone replacement at physiological levels and (v) progesterone replacement at at high levels, and (vi) sham. The sham group was subdivided into four subgroups: (i) proestrus, (ii) estrus, (iii) metaestrus, and (iv) diestrus. Ten days after surgery, the animals were sacrificed and their plasma and renal catecholamine levels measured for intergroup comparisons. Gonadectomy led to an increase in the plasma catecholamine concentration in females, as well as in the renal catecholamine content of both male and female rats. Gonadectomized males also showed a lower level of plasma catecholamine than the controls. The urinary flow, and the fractional excretion of sodium and chloride were significantly increased in gonadectomized males and in the OVX group when compared with their respective sham groups.

Background: Ultrasound lipoclasia (USL) on white adipose tissue (WAT) has been largely used in the treatment of cellulite. Nevertheless, the acute consequences of this therapy on metabolism and biochemical profile are significant and should be taken into account., Objectives: To analyze the acute metabolic effects of USL in WAT of healthy rats using analyses of body composition, biochemical profile, and inflammatory markers., Methods: Female Wistar rats weighing approximately 250 g were divided into two groups (n=10 each): control and treated. The treated group was submitted to USL, a single 3-MHz ultrasound application (5.6 W/cm(2)), in gluteal-femoral WAT (3 cm(2)) for 3 minutes. Animals were subjected to glycemic control. Body composition was analyzed using bio-impedance, and lipid profile, insulinemia, C-reactive protein (CRP), and lactate dehydrogenase (LDH) were measured., Results: USL reduced (p<.05) body fat mass. The basal metabolic rate was found to have increased (p<.05). Basal insulin and the lipoprotein profile were not different, although the glycemic curve and CRP and LDH (p<.05) levels were higher., Conclusions: Fat mobilization using USL provokes acute hyperglycemia and enhances an acute inflammatory response, producing cardiometabolic risk in female rats.

The renin-angiotensin system plays a role in the pathophysiology of renovascular hypertension. In addition, some studies have demonstrated a beneficial effect of L-arginine (L-Arg), the precursor of nitric oxide (NO), in this model of hypertension. This study was designed to investigate the effects of L-Arg on cardiovascular parameters and on the activity of the angiotensin-converting enzyme (ACE), after 14 days of renovascular hypertension. The experiments were performed on conscious male Wistar rats. Two-kidney, one-clip renovascular hypertension (2KIC) was initiated in rats by clipping the left renal artery during 14 days, while control rats were sham-operated. One group was submitted to a similar procedure and treated with L-Arg (10 mg/ml; average intake of 300mg/day) from the 7th to the 14th day after surgery, whereas the respective control group received water instead. At the end of the treatment period, the mean arterial pressure (MAP) was measured in conscious animals. The rats were sacrificed and the ACE activity was assayed in heart and kidneys, using Hip-His-Leu as substrate. In a separate group, the heart was removed, the left ventricle (LV) was weighed and the LV/body weight ratios (LV/BW) were determined. We observed significant differences in MAP between the L-Arg-treated and untreated groups (129 +/- 7 vs. 168 +/- 6 mmHg; P< 0.01). The cardiac hypertrophy described for this model of hypertension was attenuated in the 2K1C-L-Arg-treated group (14th day, wet LV/BW: 2K1C-L-Arg = 1.88 +/- 0.1; 2K1C = 2.20 +/- 0.1 mg/g; P < 0.05). L-Arg administration caused an important decrease in cardiac ACE activity (2K1C-L-Arg: 118 +/- 15; 2K1C: 266 +/- 34 micromol/min/mg; P < 0.01). L-Arg also decreased the ACE activity in the clipped kidney by 47% (P < 0.01), but not in the nonclipped kidney. These data suggest that increased NO formation and reduced angiotensin II formation are involved in the anthihypertensive effect of orally administered L-arginine.

The contributions of arterial baroreceptor and Bezold-Jarisch reflexes, and atrial natriuretic factor (ANF) to the anti-hypertensive effect of the diuretic chlorthalidone were investigated in rats with deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Chlorthalidone (8 mg rat(-1)day(-1)added to food) was given to one group during all 20 days of DOCA (8 mg kg(-1)s.c. twice per week) administration (preventive regimen) and, to another group, 20 days after DOCA treatment was initiated until the 40th day (therapeutic regimen). DOCA caused a significant increase in mean arterial pressure, reduced arterial baroreflex, and increased both the Bezold-Jarisch reflex and pro-ANF converting enzyme activity. Chlorthalidone reversed or prevented the DOCA-salt-induced hypertension, which was accompanied by the normalization of both the arterial baroreflex and the Bezold-Jarisch reflex. Additionally, both preventive and therapeutic regimens with chlorthalidone did cause normalization of the plasma sodium concentration and pro-ANF converting enzyme activity in the left atrium that follows DOCA-salt hypertension. Although it is difficult to determine the relative importance of each of the above regulatory mechanisms altered by chlorthalidone treatment, these data indicate that they may account for the prevention or decrease of DOCA-salt-induced hypertension in rats., (Copyright 2000 Academic Press.)

The excessive stimulation of beta-adrenergic receptors in the heart induces myocardial hypertrophy. There are several experimental data suggesting that this hypertrophy may also depend, at least partially, on the increase of local production of angiotensin II secondary to the activation of the cardiac renin-angiotensin system. In this study we investigated the effects of isoproterenol on the activity of angiotensin-converting enzyme (ACE) in the heart and also in the aorta and plasma. Male Wistar rats weighing 250 to 305 g were treated with a dose of (+/-)-isoproterenol (0.3 mg kg-1 day-1, N = 8) sufficient to produce cardiac hypertrophy without deleterious effects on the pumping capacity of the heart. Control rats (N = 7) were treated with vehicle (corn oil). The animals were killed one week later. ACE activity was determined in vitro in the four cardiac chambers, aorta and plasma by a fluorimetric assay. A significant hypertrophy was observed in both ventricular chambers. ACE activity in the atria remained constant after isoproterenol treatment. There was a significant increase (P < 0.05) of ACE activity in the right ventricle (6.9 +/- 0.9 to 8.2 +/- 0.6 nmol His-Leu g-1 min-1) and in the left ventricle (6.4 +/- 1.1 to 8.9 +/- 0.8 nmol His-Leu g-1 min-1). In the aorta, however, ACE activity decreased (P < 0.01) after isoproterenol (41 +/- 3 to 27 +/- 2 nmol His-Leu g-1 min-1) while it remained unchanged in the plasma. These data suggest that ACE expression in the heart can be increased by stimulation of beta-adrenoceptors. However, this effect is not observed on other local renin-angiotensin systems, such as the aorta. Our data also suggest that the increased sympathetic discharge and the elevated plasma concentration of catecholamines may contribute to the upregulation of ACE expression in the heart after myocardial infarction and heart failure.

An increase in angiotensin-converting enzyme (ACE) activity has been observed in the heart after myocardial infarction (MI). Since most studies have been conducted in chronically infarcted individuals exhibiting variable degrees of heart failure, the present study was designed to determine ACE activity in an earlier phase of MI, before heart failure development. MI was produced in 3-month old male Wistar rats by ligation of the anterior branches of the left coronary artery, control rats underwent sham surgery and the animals were studied 7 or 15 days later. Hemodynamic data obtained for the anesthetized animals showed normal values of arterial blood pressure and of end-diastolic pressure in the right and left ventricular cavities of MI rats. Right and left ventricular (RV, LV) muscle and scar tissue homogenates were prepared to determine ACE activity in vitro by measuring the velocity of His-Leu release from the synthetic substrate Hyp-His-Leu. ACE activity was corrected to the tissue wet weight and is reported as nmol His-Leu g-1 min-1. No significant change in ACE activity in the RV homogenates was demonstrable. A small nonsignificant increase of ACE activity (11 +/- 9%; P > 0.05) was observed 7 days after MI in the surviving left ventricular muscle. Two weeks after surgery, however, ACE activity was 46 +/- 11% (P < 0.05) higher in infarcted rats compared to sham-operated rats. The highest ACE activity was demonstrable in the scar tissue homogenate. In rats studied two weeks after surgery, ACE activity in the LV muscle increased from 105 +/- 7 nmol His-Leu g-1 min-1 in control hearts to 153 +/- 11 nmol His-Leu g-1 min-1 (P < 0.05) in the remaining LV muscle of MI rats and to 1051 +/- 208 nmol His-Leu g-1 min-1 (P < 0.001) in the fibrous scar. These data indicate that ACE activity increased in the heart after infarction before heart failure was demonstrable by hemodynamic measurements. Since the blood vessels of the scar drain to the remaining LV myocardium, the high ACE activity present in the fibrous scar may increase the angiotensin II concentration and decrease bradykinin in the cardiac tissues surrounding the infarcted area. The increased angiotensin II in the fibrous scar may contribute to the reactive fibrosis and hypertrophy in the left ventricular muscle surviving infarction.

We have reported that chlorthalidone (Chlor) prevents the development of heart hypertrophy in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. The present study was carried out to determine whether Chlor (8 mg/day per animal, added to the food, for 20 days) affects kidney and heart hypertrophy in DOCA-salt (8 mg/kg, sc, twice a week) rats by causing alterations in protein and peptide hydrolysis. Heart (left ventricle) and kidney enzyme activities were measured in tissue homogenates from normal-control, salt-control, DOCA-salt and DOCA-salt-Chlor male Wistar rats (N = 6 for each group), using azocasein as the substrate for proteolytic enzymes and specific peptides for prolylendopeptidase (PEP) and multicatalytic proteinase (MCP). The tissue weight/body weight ratio increased in parallel to elevation of blood pressure. The left ventricular muscle hypertrophy (26%, P < 0.05) present in the DOCA-salt hypertensive group was completely prevented by simultaneous Chlor treatment. Chlor treatment did not change the kidney hypertrophy (+79%, P < 0.;05) observed in the salt-control (+57%, P < 0.05) and DOCA-salt (+74%, P < 0.05) groups. The hydrolysis of peptides by PEP and MCP was similar in the normal and salt-control groups. The heart PEP activity was 24% higher (P < 0.01) in DOCA-salt rats, whereas MCP activity was not different when compared to control groups. DOCA-salt treatment increased MCP activity in the kidney by 44% while PEP activity did not differ from that of control groups. The hydrolysis of proteins by heart enzymes was increased by salt by 47%. Chlor treatment restored the reduction in protein hydrolysis induced by DOCA-salt (a 21% decrease, P < 0.05) to a level similar to that of the normal-control group. Similarly, Chlor coadministration prevented the 30% reduction in renal proteolytic activity elicited by DOCA-salt treatment. Although Chlor treatment prevented the DOCA-salt-induced reduction in protein hydrolysis, this response did not interfere with kidney hypertrophy. The mechanism by which hypertension produces hypertrophy is unclear, but our results suggest that this structural modification is not related to the activities of some peptidases, e.g. protein and peptide hydrolases.

Heart tissue contains large amounts of the Ca(2+)-activated proteinase calpain which has been assigned a specific function in the turnover of muscle protein. The objective of the present study was to determine calpain (E.C. 3.4.22.17)-like activity in homogenates of left ventricle from hypertensive rats that developed ventricular hypertrophy. Calpain activity was assayed using heat-denatured azocasein as a substrate in the presence of 1 mM calcium and corrected by subtraction of the Ca(2+)-independent activities. The latter were measured in the presence of 1 mM EGTA and the products read at 440 nm. Male Wistar rats (225 g) were assigned to control (N = 8, normal drinking water), salt (N = 6, drinking water containing 1% NaCl) and DOCA-salt (N = 6, deoxycorticosterone acetate, 8 mg/kg, sc, twice a week for 20 days plus drinking water containing 1% NaCl) groups. SHR (N = 6, spontaneously hypertensive rats) were also used. The calpain activity of the control group was at 3.90 +/- 0.22 mU/g wet weight tissue. Hypertension induced significant left ventricular hypertrophy in DOCA-salt rats (26%) and in SHR (54%) and a 30% decrease in calpain activity in both groups (P < 0.01). In the high salt load (salt group) calpain activity was also decreased, but this was not accompanied by hypertrophy. In the present indirect measurement of protein degradation capacity of heart tissue homogenates the proteolytic activity was activated (221%) by 1 mM calcium and inhibited (84%) by 1 mM EGTA after a 48-h incubation period, indicating the destruction of the calpain inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)

1. Heart mass, prolyl endopeptidase activity and fractionated proteins from heart tissue were studied in one-kidney, one clip hypertensive rats (N = 6) and compared to sham-operated rats (N = 6). 2. Body weight, arterial pressure and tissue mass were measured 4 weeks after artery clipping. Z-Gly-Pro-p-nitroaniline hydrolysis was used to measure tissue prolyl endopeptidase activity in the homogenate. Protein was fractionated into the soluble and myofibrillar fractions. 3. In the normotensive rats, prolyl endopeptidase activity expressed in terms of protein specific activity (microM substrate hydrolyzed h-1 mg supernatant protein-1) occurred in atria and was 2.5-fold higher than in the ventricles (3.79 +/- 0.20 vs 1.44 +/- 0.02, P < 0.05). In the one-kidney, one clip hypertensive rats, the left ventricle tissue increased 1.7-fold (2.27 +/- 0.11 vs 3.72 +/- 0.11 mg wet weight tissue/g body weight, P < 0.001), the soluble protein fraction (54.86 +/- 3.60 vs 57.38 +/- 6.64 mg/g wet weight tissue) was unchanged, while the myofibrillar fraction increased 1.9-fold (118.9 +/- 9.09 vs 229.8 +/- 8.47 mg/g wet weight tissue, P < 0.001). 4. The specific activity of the atrial and ventricular prolyl endopeptidase decreased in atria and increased in ventricles as the result of hypertension (3.79 +/- 0.2 vs 2.84 +/- 0.13 and 1.44 +/- 0.02 vs 1.87 +/- 0.13; respectively). These regional differences in prolyl endopeptidase enzyme content caused by one-kidney, one clip hypertension in neurosecretory and non-neurosecretory heart areas suggest that this enzyme plays a local role in the turnover of specific polypeptides.

Diuretics have been the mainstay of long-term treatment of hypertension, but there is no evidence suggesting that diuretics may be effective in reducing cardiac hypertrophy associated with hypertension. Thus, the present study was carried out to elucidate if long-term treatment with chlorthalidone (8 mg per animal per day added to food) affects the development of and reverses the ventricular hypertrophy in deoxycorticosterone acetate (DOCA) (8 mg/kg SC twice a week)-salt hypertensive rats. Chlorthalidone was given to one group during all 20 days of DOCA administration (preventive regimen) and to another group 20 days after DOCA treatment was initiated until the 40th day (therapeutic regimen). Chlorthalidone was found to reduce or prevent the development of ventricular hypertrophy, as assessed by a reduction in ventricular mass and cardiac protein as well as arterial hypertension. Both chlorthalidone regimens prevented the increase or induced a significant decrease in the plasma concentration of sodium and in cardiac sympathetic tone, which were both increased in DOCA-salt-treated rats. These data provide evidence that long-term chlorthalidone treatment is effective in preventing or reducing ventricular hypertrophy along with arterial hypertension. However, whether this is due to a reduction in plasma sodium or other additional mechanisms, such as a reduction in cardiac sympathetic tone, remains to be determined.

Highly purified rabbit brain endo-oligopeptidase A injected into goats produced, after 60 days of immunization, antisera that specifically inhibit purified rabbit brain endo-oligopeptidase A. An immunoreactive kininase having the same specificity as rabbit brain endo-oligopeptidase A for bradykinin was detected in several rabbit tissues. The highest amount of this immunoreactive kininase was found in the 25000 g supernatant fraction (S fraction) of heart, liver, skeletal muscle, ovary, brain and testis homogenates, corresponding to 89, 86, 78, 59, 56 and 53% respectively of the whole kininase activity found in the S fraction.

Two endopeptidases displaying similar specificities towards peptide hormone substrates but differing in molecular size have been identified in rabbit heart and isolated by a combination of ion-exchange chromatography, gel filtration and preparative gel electrophoresis. These two enzymes share several properties with the previously described rabbit brain endooligopeptidase A. They were shown to produce, by a single peptide bond cleavage, [Met5] enkephalin and [Leu5]enkephalin from small enkephalin containing peptides. They also hydrolyze the Phe5-Ser5 bond of bradykinin and the Arg8-Arg9 bond of neurotensin. Characteristically, the activity of both low and high Mr enzymes is restricted to oligopeptides. Both forms of heart endooligopeptidase A are inhibited by antibodies raised against the brain enzyme. When electrophoresed in SDS-polyacrylamide gel under denaturing conditions, the low Mr heart enzyme shows a major band of Mr = 73,000, comparable in size to the brain enzyme. The SDS-PAGE of the high and low Mr enzymes analyzed by immunoblotting with an antibody raised against low Mr brain endooligopeptidase A, showed a major antigen band corresponding to Mr = 72,000. In addition, immunoblotting has also demonstrated that a monoclonal antibody antitubulin reacts with a polypeptide corresponding to Mr = 50,000 present in the purified high Mr endooligopeptidase A. Both enzymes are activated by dithiothreitol and inhibited by thiol reagents, but are not affected by leupeptin, DFP or EDTA, thus indicating that they should be classified as nonlysosomal cysteinyl-endooligopeptidase A.

The distribution and properties of neutral peptidases acting on the peptide hormone bradykinin (Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg) were determined in several rabbit tissues. The supernatant and particulate fractions prepared from tissue homogenates (25000g for 60min) were studied. Bradykinin inactivation (kininase activity) was measured by bioassay with the isolated guinea-pig ileum. The sites of peptide-bond cleavage were determined in the amino acid analyser, which permits detection and measurement of amino acids and peptides derived from bradykinin. The results indicate that kininases are present in a wide range of concentrations in different tissues, kidney and lung having the most activity. Kininases present in different tissues were distinguished on the basis of sensitivity to the effects of EDTA, dithiothreitol and ZnCl2 and by the site of peptide-bond hydrolysis in bradykinin.

Objective: To assess the efficacy and safety of a new non-invasive body contouring device in patients with localized fat in abdomen or in abdomen and hips. Additionally, we also evaluated the patient satisfaction with the procedure. Methods: Prospective and non-randomized open label study. The patients underwent four sessions, separated by 1 week each, with the Alma PrimeX, a non-invasive body contouring device that combines pulsed non-focus ultrasound and a Unipolar radiofrequency. The primary end point was the mean change in fat tissue thickness, assessed by diagnostic ultrasound, from baseline to 3-months after the last treatment-session. Results: Fifteen subjects were evaluated. As compared to pre-treatment thickness, Hodges-Lehmann median difference (95% CI) was − 85.3 (− 107.5 to − 62.0) mm, p = 0.0001; − 70.3 (− 95.0 to − 48.5) mm, p = 0.0001; − 100.0 (− 140.5 to − 49.5) mm, p = 0.0039; and − 71.8 (− 132.5 to − 23.0) mm, p = 0.0078 in infraumbilical, supraumbilical, right hip, and left hip, respectively. Pretreatment fat volume was significantly reduced from 32.9% to 31.2%, p = 0.0006. The median (interquartile range) degree of patient satisfaction was 4.0 (1.0–5.0), with 13 (86.7%) patients being "Highly satisfied" or "Satisfied" with the treatment results. The most common adverse event was discomfort, followed by erythema. All the adverse events were mild and were successfully resolved without treatment. Conclusions: Combine therapy of a Pulsed non-focus ultrasound and Unipolar radiofrequency using the non-invasive device Alma PrimeX was an effective and safe treatment for reducing fat tissue thickness in abdomen and hips in patients with localized fat. Patients' satisfaction with the procedure was high. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is a chronic and complex neurodegenerative disease, distinguished by the presence of lesions in the central nervous system (CNS) due to exacerbated immunological responses that inflict oligodendrocytes and the myelin sheath of axons. In recent years, studies have focused on targeted therapeutics for MS that emphasize the role of G protein-coupled receptors (GPCRs), specifically cannabinoids receptors. Clinical studies have suggested the therapeutic potential of cannabinoids derived from Cannabis sativa in relieving pain, tremors and spasticity. Cannabinoids also appear to prevent exaggerated immune responses in CNS due to compromised blood–brain barrier. Both, endocannabinoid system (ECS) modulators and cannabinoid ligands actively promote oligodendrocyte survival by regulating signaling, migration and myelination of nerve cells. The cannabinoid receptors 1 (CB1) and 2 (CB2) of ECS are the main ones in focus for therapeutic intervention of MS. Various CB1/CB2 receptors agonists have been experimentally studied which showed anti-inflammatory properties and are considered to be effective as potential therapeutics for MS. In this review, we focused on the exacerbated immune attack on nerve cells and the role of the cannabinoids and its interaction with the ECS in CNS during MS pathology. [ABSTRACT FROM AUTHOR]

Adrenal tumors are common tumors in urology and they can be further divided into functioning and nonfunctioning tumors according to whether there is uncommon endocrine function. In clinical practice, the early identification and accurate assessment of adrenal tumors are essential for the guidance of subsequent treatment. However, a nonfunctioning adrenal tumor often lacks obvious clinical symptoms, making it difficult to be timely and precisely diagnosed by conventional examinations. Therefore, a rapid and accurate method for identifying the functioning and nonfunctioning adrenal tumors is urgently required to achieve precise treatment of adrenal tumors. In this study, surface-enhanced Raman spectroscopy was investigated as a diagnostic tool to identify the blood serum samples from healthy volunteers as well as the patients with functioning and nonfunctioning adrenal tumors. Based on the SERS peak analysis, abnormal glycolysis, DNA/RNA, and amino acid metabolites were found to be potential biomarkers for identifying patients with adrenal tumors, while metabolites related to disordered protein catabolism and excessive hormone secretion were expected to further differentiate functioning adrenal tumors from nonfunctioning adrenal tumors. In addition, principal component analysis followed by support vector machine (PCA-SVM) was further applied on those serum SERS measurements, and the classification accuracies of 96.8% and 84.5% were achieved for differentiating healthy group versus adrenal tumor group and functioning adrenal tumor group versus nonfunctioning adrenal tumor group, respectively. The results have demonstrated the prodigious potential of precise adrenal tumor diagnosis by using the blood serum surface-enhanced Raman spectroscopy technique. [ABSTRACT FROM AUTHOR]

Background: Crack-cocaine dependence is a serious public health issue, related to several psychiatric and psychosocial problems. Crack-cocaine users are usually embedded in a context of great social vulnerability, often associated with violence, poverty, family conflict and easy and early access to alcohol, tobacco and other drugs.Methods: This cross-sectional study enrolled a consecutive sample of 577 patients admitted to 20 therapeutic communities located in Southern Brazil, between September 2012 and September 2013. A structured interview assessed life-time exposure to risk and protective factors for drug use, such as parental monitoring in childhood, deviant behaviors and peer pressure.Results: Presence of family conflict (p = 0.002), maltreatment (p = 0.016), and deviant behavior prior to age 15 in a bivariate analysis predicted an earlier age of crack-cocaine initiation, whereas adolescents experiencing parental monitoring during adolescence started use later (p < 0.001). In the multivariate model, perceptions related to ease of access of illicit drugs (marijuana: p = 0.028, 95% CI = - 3.81, - 0.22; crack-cocaine: p < 0.001, 95% CI = - 7.40, - 4.90), and deviant behavior (threatening someone with a gun: p = 0.028, 95% CI = - 2.57, - 0.14) remained independent predictors of early age of crack-cocaine initiation.Conclusions: Early onset of crack-cocaine use seems to be associated with exposure to family conflict, easy access to drugs and deviant behavior. Treatment and preventive programs should take these factors into account when designing and implementing community interventions. [ABSTRACT FROM AUTHOR]

Crack cocaine is the crystal form of cocaine, produced by adding sodium bicarbonate to cocaine base paste. Brazil is the largest consumer of crack cocaine in the world. Users of crack cocaine show important physiological and behavioral alterations, including neuropsychiatric symptoms, such as anxiety-related symptoms. Nevertheless, few pre-clinical studies have been previously performed to understand the neurobiological effects of crack cocaine. The purpose of the present study was to investigate effects of the subchronic treatment (5 days, IP) of rats with crack cocaine in an animal model of anxiety/panic, the elevated T-maze (ETM). The ETM model allows the measurement of two behavioral defensive responses, avoidance and escape, in clinical terms, respectively, associated to generalized anxiety and panic disorder, the two main psychiatric conditions that accompany substance use disorders. Immediately after the ETM model, animals were tested in an open field for locomotor activity assessment. Analysis of delta FosB protein immunoreactivity was used to map areas activated by crack cocaine exposure. Results showed that crack treatment selectively altered escape displayed by rats in the ETM test, inducing either a panicolytic (18 mg/kg IP) or a panicogenic-like effect (25 and 36 mg/kg IP). These effects were followed by the altered functioning of panic-modulating brain regions, i.e., the periaqueductal gray and the dorsal region and lateral wings of the dorsal raphe nucleus. Treatment with 36 mg/kg of crack cocaine also increased locomotor activity. These are the first observations performed with crack cocaine in a rodent model of anxiety/panic and contribute to a better understanding of the behavioral and neurobiological effects of crack cocaine. [ABSTRACT FROM AUTHOR]

Obesity increases sympathetic nerve activity (SNA) in men, but not women. Here, we review current evidence suggesting that sexually dimorphic sympathoexcitatory responses to leptin and insulin may contribute. More specifically, while insulin increases SNA similarly in lean males and females, this response is markedly amplified in obese males, but is abolished in obese females. In lean female rats, leptin increases a subset of sympathetic nerves only during the high estrogen proestrus reproductive phase; thus, in obese females, because reproductive cycling can become impaired, the sporadic nature of leptin-induced sympathoexcitaton could minimize its action, despite elevated leptin levels. In contrast, in males, obesity preserves or enhances the central sympathoexcitatory response to leptin, and current evidence favors leptin's contribution to the well-established increases in SNA induced by obesity in men. Leptin and insulin increase SNA via receptor binding in the hypothalamic arcuate nucleus and a neuropathway that includes arcuate neuropeptide Y (NPY) and proopiomelanocortin (POMC) projections to the paraventricular nucleus. These metabolic hormones normally suppress sympathoinhibitory NPY neurons and activate sympathoexcitatory POMC neurons. However, obesity appears to alter the ongoing activity and responsiveness of arcuate NPY and POMC neurons in a sexually dimorphic way, such that SNA increases in males but not females. We propose hypotheses to explain these sex differences and suggest areas of future research. [ABSTRACT FROM AUTHOR]

Background and objectives: Nowadays, there are several noninvasive technologies being used for improving of body contouring. The objectives of this pilot study were to verify the effectiveness of the Heccus® device, emphasizing the synergism between nonfocused ultrasound plus Aussie current in the improvement of body contour, and to determine if the association of this therapy with whole-body vibration exercises can have additional positive effects in the results of the treatments. Subjects and methods: Twenty healthy women aged 20-40 years participated in the study. Ten patients received Combined Therapy treatment (G1) and the other 10 participants received Combined Therapy with additional vibratory platform treatment (G2). Anthropometric and standardized photography analysis, ultrasonography, cutometry and self-adminestered questionnaires of tolerance and satisfaction levels with the treatment were used. Results: Compared with baseline values, reduction of fat thickness was observed by ultrasonography in the posterior thigh area in the G1 group (P<0.05) and in the buttocks (P<0.05) and the posterior thigh areas (P<0.05) in the G2. All the treated areas in both groups showed reduction in cellulite degree in the buttocks, G1 (P<0.05) and G2 (P<0.05), and in posterior thigh areas, G1 (P<0.05) and G2 (P<0.05). Optimal improvement of skin firmness (G1, P<0.0001; G2, P=0.0034) in the treated areas was observed in both groups. Conclusion: We conclude that the synergistic effects of the Combined Therapy (nonfocused ultrasound plus Aussie current) might be a good option with noninvasive body contouring treatment for improving the aspect of the cellulite, skin firmness and localized fat. If used in association with the whole-body vibratory platform, the results can be better, especially in the treatment of localized fat. Further studies with larger sample size should be performed to confirm these results. [ABSTRACT FROM AUTHOR]

The neurotoxin MPTP has long been used to create a mouse model of Parkinson’s disease (PD). Indeed, several MPTP analogues have been developed, including 2′-CH3-MPTP, which was shown to induce nigrostriatal DA neuronal depletion more potently than MPTP. However, no study on behavioral and molecular alterations in response to 2′-CH3-MPTP has been carried out so far. In the present work, 2′-CH3-MPTP was administered to mice (2.5, 5.0 and 10 mg/kg per injection, once a day, 5 days) and histological, biochemical, molecular and behavioral alterations were evaluated. We show that, despite a dose-dependent-like pattern observed for nigrostriatal dopaminergic neuronal death and dopamine depletion, dose-specific alterations in dopamine metabolism and in the expression of dopaminergic neurotransmission-associated genes could be related to specific motor deficits elicited by the different doses tested. Interestingly, 2′-CH3-MPTP leads to increased DAT and MAO-B transcription, which could explain, respectively, its higher potency and the requirement of higher doses of MAO inhibitors to prevent nigrostriatal neuronal death when compared to MPTP. Also, perturbations in dopamine metabolism as well as possible alterations in dopamine bioavailability in the synaptic cleft were also identified and correlated with strength and ambulation deficits in response to specific doses. Overall, the present work brings new evidence supporting the distinct effects of 2′-CH3-MPTP when compared to its analogue MPTP. Moreover, our data highlight the utmost importance of a precise experimental design, as different administration regimens and doses yield different biochemical, molecular and behavioral alterations, which can be explored to study specific aspects of PD. [ABSTRACT FROM AUTHOR]

The renin-angiotensin system (RAS) is a key player in the control of the cardiovascular system and hydroelectrolyte balance, with an influence on organs and functions throughout the body. The classical view of this system saw it as a sequence of many enzymatic steps that culminate in the production of a single biologically active metabolite, the octapeptide angiotensin (ANG) II, by the angiotensin converting enzyme (ACE). The past two decades have revealed new functions for some of the intermediate products, beyond their roles as substrates along the classical route. They may be processed in alternative ways by enzymes such as the ACE homolog ACE2. One effect is to establish a second axis through ACE2/ANG-(1-7)/MAS, whose end point is the metabolite ANG- (1-7). ACE2 and other enzymes can form ANG-(1-7) directly or indirectly from either the decapeptide ANG I or from ANG II. In many cases, this second axis appears to counteract or modulate the effects of the classical axis. ANG-(1-7) itself acts on the receptor MAS to influence a range of mechanisms in the heart, kidney, brain, and other tissues. This review highlights the current knowledge about the roles of ANG-(1-7) in physiology and disease, with particular emphasis on the brain. [ABSTRACT FROM AUTHOR]

Brazil is a global agricultural commodity producer and the largest consumer of pesticides. Pesticide use in Brazil comprised 549 280 tons in 2018. In the country, soybean, corn, and sugar cane are extensively produced, which are the most pesticides demanding crops. In the last years, the records of new pesticides were the highest in the historical series. They can persist in soil or water, accumulate in organisms, and contaminate workers and the general population through the air, water, or food. This review aimed to gather toxicological data obtained by animal models exposed to 4 pesticides: glyphosate, chlorpyrifos, abamectin, and 2,4-D. An additional goal was to compose an overview of how this subject has been approached, surveying which research groups are working on this field, where they are located, and relations with pesticides used in those regions. We collected the papers from the platforms PubMed, Scopus, Scielo, and Web of Science, performed in Brazil from 2014 to 2019. After two-step blind selection using the software Rayyan QCRI by different authors, 67 studies were selected to extract data. We observed that research is more concentrated in the South region, followed by the Southeast and Midwest, with 43%, 32%, and 23% of the studies, respectively. The prevalent institutions are from the states of Rio Grande do Sul, São Paulo, and Goiás. The effects on a variety of biomarkers help predict the potential risks to humans and nontarget organisms. The prevalent animal model was fish (36%). Overall, the main toxic effects evaluated were mortality, abnormalities in the blood cells, developmental abnormalities, and behavior alterations. Integr Environ Assess Manag 2021;17:507-520. © 2020 SETAC., (© 2020 SETAC.)

Parkinson's disease (PD) is the second most common neurodegenerative disease in the world, being characterized by dopaminergic neurodegeneration of substantia nigra pars compacta. PD pharmacotherapy has been based on dopamine replacement in the striatum with the dopaminergic precursor 3,4-dihydroxyphenylalanine ( l-DOPA) and/or with dopaminergic agonists, alongside anticholinergic drugs in order to mitigate the motor abnormalities. However, these practices neither prevent nor stop the progression of the disease. Environmental enrichment (EE) has effectively prevented several neurodegenerative processes, mainly in preclinical trials. Several studies have demonstrated that EE induces biological changes, bearing on cognitive enhancement, neuroprotection, and on the attenuation of the effects of stress, anxiety, and depression. Herein, we investigated whether EE could prevent the motor, biochemical, and molecular abnormalities in a murine model of PD induced by 1-methyl-4-phenyl-2,3-dihydropyridine (MPTP). Our results show that EE does not prevent the dopaminergic striatal depletion induced by MPTP, despite having averted the MPTP-induced hyperlocomotion. However, it was able to slow down and avoid, respectively, the 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) depletion. Analysis of dopaminergic mRNA alterations in the midbrain showed that D1R expression was increased by MPTP, while the normal expression level of this receptor was restored by EE. As for the cholinergic system, MPTP led to a decrease in the ChAT gene expression while increasing the expression of both AChE and M1R. EE attenuated and prevented-respectively-ChAT and M1R gene expression alterations triggered by MPTP in the midbrain. Overall, our data brings new evidence supporting the neuroprotective potential of EE in PD, focusing on the interaction between dopaminergic and cholinergic systems. [ABSTRACT FROM AUTHOR]

Several soil-derived Actinobacteria produce secondary metabolites that are proven specific and potent inhibitors of the human angiotensin-I-converting enzyme (ACE), a key target for the modulation of hypertension through its role in the renin-angiotensin-aldosterone system. K-26-DCP is a zinc dipeptidyl carboxypeptidase (DCP) produced by Astrosporangium hypotensionis, and an ancestral homologue of ACE. Here we report the high-resolution crystal structures of K-26-DCP and of its complex with the natural microbial tripeptide product K-26. The experimental results provide the structural basis for better understanding the specificity of K-26 for human ACE over bacterial DCPs. Database Structural data are available in the PDB under the accession numbers and . [ABSTRACT FROM AUTHOR]

It has been postulated that the protective effects of lower body subcutaneous adipose tissue (LBSAT) occur via its ability to sequester surplus lipid and thus serve as a “metabolic sink.” However, the mechanisms that mediate this protective function are unknown thus this study addresses this postulate. Ad libitum, chow-fed mice underwent Sham-surgery or LBSAT removal (IngX, inguinal depot removal) and were subsequently provided chow (Chow; typical adipocyte expansion) or high fat diet (HFD; enhanced adipocyte expansion) for 5 weeks. Primary outcome measures included glucose tolerance and subsequent insulin response, muscle insulin sensitivity, liver and muscle triglycerides, adipose tissue gene expression, and circulating lipids and adipokines. In a follow up study the consequences of extended experiment length post-surgery (13 wks) or pre-existing glucose intolerance were examined. At 5 wks post-surgery IngX in HFD-fed mice reduced glucose tolerance and muscle insulin sensitivity and increased circulating insulin compared with HFD Sham. In Chow-fed mice, muscle insulin sensitivity was the only measurement reduced following IngX. At 13 wks circulating insulin concentration of HFD IngX mice continued to be higher than HFD Sham. Surgery did not induce changes in mice with pre-existing glucose intolerance. IngX also increased muscle, but not liver, triglyceride concentration in Chow- and HFD-fed mice 5 wks post-surgery, but chow group only at 13 wks. These data suggest that the presence of LBSAT protects against triglyceride accumulation in the muscle and HFD-induced glucose intolerance and muscle insulin resistance. These data suggest that lower body subcutaneous adipose tissue can function as a “metabolic sink.” [ABSTRACT FROM AUTHOR]

It is well established that cardiac remodeling plays a pivotal role in the development of heart failure, a leading cause of death worldwide. Meanwhile, sympathetic hyperactivity is an important factor in inducing cardiac remodeling. Therefore, an in-depth understanding of beta-adrenoceptor signaling pathways would help to find better ways to reverse the adverse remodeling. Here, we reviewed five pathways, namely mitogen-activated protein kinase signaling, Gs-AC-cAMP signaling, Ca-calcineurin-NFAT/CaMKII-HDACs signaling, PI3K signaling and beta-3 adrenergic signaling, in cardiac remodeling. Furthermore, we constructed a cardiac-remodeling-specific regulatory network including miRNA, transcription factors and target genes within the five pathways. Both experimental and clinical studies have documented beneficial effects of beta blockers in cardiac remodeling; nevertheless, different blockers show different extent of therapeutic effect. Exploration of the underlying mechanisms could help developing more effective drugs. Current evidence of treatment effect of beta blockers in remodeling was also reviewed based upon information from experimental data and clinical trials. We further discussed the mechanism of how beta blockers work and why some beta blockers are more potent than others in treating cardiac remodeling within the framework of cardiac remodeling network. [ABSTRACT FROM AUTHOR]

It is believed that cardiac remodeling due to geometric and structural changes is a major mechanism for the progression of heart failure in different pathologies including hypertension, hypertrophic cardiomyopathy, dilated cardiomyopathy, diabetic cardiomyopathy, and myocardial infarction. Increases in the activities of proteolytic enzymes such as matrix metalloproteinases, calpains, cathepsins, and caspases contribute to the process of cardiac remodeling. In addition to modifying the extracellular matrix, both matrix metalloproteinases and cathepsins have been shown to affect the activities of subcellular organelles in cardiomyocytes. The activation of calpains and caspases has been identified to induce subcellular remodeling in failing hearts. Proteolytic activities associated with different proteins including caspases, calpain, and the ubiquitin-proteasome system have been shown to be involved in cardiomyocyte apoptosis, which is an integral part of cardiac remodeling. This article discusses and compares how the activities of various proteases are involved in different cardiac abnormalities with respect to alterations in apoptotic pathways, cardiac remodeling, and cardiac dysfunction. An imbalance appears to occur between the activities of some proteases and their endogenous inhibitors in various types of hypertrophied and failing hearts, and this is likely to further accentuate subcellular remodeling and cardiac dysfunction. The importance of inhibiting the activities of both extracellular and intracellular proteases specific to distinct etiologies, in attenuating cardiac remodeling and apoptosis as well as biochemical changes of subcellular organelles, in heart failure has been emphasized. It is suggested that combination therapy to inhibit different proteases may prove useful for the treatment of heart failure. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effect of overstimulation of β-adrenoceptors on vascular inflammatory mediators. Wistar rats were treated with the β-adrenoceptor agonist isoproterenol (0.3 mg·kg-1·day-1 sc) or vehicle (control) for 7 days. At the end of treatment, the right carotid artery was catheterized for arterial and left ventricular (LV) hemodynamic evaluation. Isoproterenol treatment increased LV weight but did not change hemodynamic parameters. Aortic mRNA and protein expression were quantified by real-time RT-PCR and Western blot analysis, respectively. Isoproterenol enhanced aortic mRNA and protein expression of IL-1β (124% and 125%) and IL-6 (23 1% and 40%) compared with controls but did not change TNF-α expression. The nuclear-to-cytoplasmatic protein expression ration of the NF-κB p65 subunit was increased by isoproterenol treatment (51%); in addition, it reduced the cytoplasmatic expression of 1κB-a (52%) in aortas. An electrophoretic mobility shift assay was performed using the aorta, and increased NF-κB DNA binding (31%) was observed in isoproterenol-treated rats compared with controls (P < 0.05). Isoproterenol treatment increased phenylephrine-induced contraction in aortic rigs (P < 0.05), which was significantly reduced by superoxide dismutase (150 U/ml) and sodium salicylate (5 mM). Cotreatment with thalidomide (150 mg·kg-1·day-1 for 7 days) also reduced hyperreactivity to phenylephrine induced by isoproterenol. En conclusion, overstimulation of β-adrenoceptors increased proinflammatory cytokines and upregulated NF-κB in the rat aorta. Moreover, local oxidative stress and the proinflammatory state seem to play key roles in the altered vascular reactivity of the rat aorta induced by chronic β-adrenergic stimulation. [ABSTRACT FROM AUTHOR]

Sympathetic hyperactivity (SH) and renin angiotensin system (RAS) activation are commonly associated with heart failure (HF), even though the relative contribution of these factors to the cardiac derangement is less understood. The role of SH on RAS components and its consequences for the HF were investigated in mice lacking α2A and α2C adrenoceptor knockout (α2A/α2CARKO) that present SH with evidence of HF by 7 mo of age. Cardiac and systemic RAS components and plasma norepinephrine (PN) levels were evaluated in male adult mice at 3 and 7 mo of age. In addition, cardiac morphometric analysis, collagen content, exercise tolerance, and hemodynamic assessments were made. At 3 mo, α2A/α2CARKO mice showed no signs of HF, while displaying elevated PN, activation of local and systemic RAS components, and increased cardiomyocyte width (16%) compared with wild-type mice (WT). In contrast, at 7 mo, α2A/α2CARKO mice presented clear signs of HF accompanied only by cardiac activation of angiotensinogen and ANG II levels and increased collagen content (twofold). Consistent with this local activation of RAS, 8 wk of ANG II AT1 receptor blocker treatment restored cardiac structure and function comparable to the WT. Collectively, these data provide direct evidence that cardiac RAS activation plays a major role underlying the structural and functional abnormalities associated with a genetic SH-induced HF in mice. [ABSTRACT FROM AUTHOR]

1. This study was performed to evaluate the effect of chronic high salt intake on local cardiac and renal components of the renin–angiotensin system (RAS) and its impact on cardiac remodelling and function after myocardial infarction (MI). 2. Rats submitted to coronary artery ligation to produce MI or sham operation (SO) were randomized to receive 1% NaCl solution or tap water as drinking water for 4 weeks. Plasma renin activity (PRA) and angiotensin-converting enzyme (ACE) activity were quantified. Tissue angiotensin (Ang) II and ACE activity were determined by ELISA and a fluorimetric assay, respectively. Renal and cardiac AT1 and AT2 receptor protein levels were quantified by western blot. 3. Independent of the lower PRA levels, MI promoted a significant increase in the left ventricular/bodyweight ratio and impaired cardiac function. The cardiac RAS was activated after MI with a significant increase in ACE activity, AngII and AT1 receptor levels. The RAS was slightly attenuated under high-salt conditions. 4. Interestingly, high salt intake increased the expression of the AT2 receptor by approximately twofold in the kidney of MI rats compared with the SO control group. Because of its natriuretic effect, the AT2 receptor may counterbalance the salt overload and prevent the additional impairment of cardiac function. 5. The present study indicates that 4 weeks after MI, high salt intake did not further increase cardiac hypertrophy or further impair cardiac function in MI rats. A chronic increase in salt intake significantly suppressed PRA, but did not prevent activation of the local RAS or the progression of cardiac remodelling and left ventricular dysfunction caused by MI. 6. The present results show that inhibition of systemic renin production with salt overload does not affect ventricular remodelling after MI in rats. This suggests that local activation of the RAS in the heart, which was not suppressed by salt overload, exerts a predominant role for local adaptations of the heart after MI. [ABSTRACT FROM AUTHOR]

Calpains are a family of 14 intracellular calcium-dependent proteases, which have been implicated in cardiovascular diseases. We aimed to analyze specifically the expressional regulation of the different calpain isoforms in hypertensive target organ damage. Using real-time PCR, we found calpain 6 and 9 down-regulated by more than 50% and the endogenous calpain inhibitor calpastatin up-regulated by 225%, respectively, in the hearts of Dahl salt-sensitive rats on a high salt (4% NaCl) compared to normal salt diet. On the protein level, calpain 9 but not calpastatin was regulated in the hypertensive target organs heart and kidney. Moreover, the myocardial expression of calpain 9 protein was inversely linked to left ventricular mass (r= -0.93, p<0.01), and renal expression of calpain 9 protein correlated inversely with albuminuria (r= -0.82, p<0.05). In the aorta, there was no regulation of calpain 9 on the protein level. We conclude that differential regulation of calpain 9 may play a role in hypertensive target organ damage. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Summary 1. Aldosterone has been considered a key hormone in the regulation of water, sodium and potassium metabolism, thus influencing blood pressure regulation. More recently, several studies have demonstrated that aldosterone is also produced in extra-adrenal tissues (e.g. the heart), suggesting a paracrine effect for aldosterone, such as to increase collagen synthesis in the heart. 2. Because aldosterone production in the heart increases after myocardial infarction (MI), we investigated the effect of chronic administration of spironolactone, an aldosterone receptor antagonist, in rats after MI compared with the effects produced by losartan and hydralazine. 3. Myocardial infarction was produced in male Wistar rats by surgical ligature of the left coronary artery. Sham-operated animals were used as controls. 4. Spironolactone (20 mg/kg per day), losartan (15 mg/kg per day) or hydralazine (20 µg/kg per day) were administered after MI and used for 1 month. 5. At the end of the treatment period, animals underwent haemodynamic recording (arterial and intraventricular pressures). The collagen content of the heart was evaluated by measuring the hydroxyproline (OH-Pro) concentration in right (RV) and left ventricle (LV) muscle fragments. 6. Infarct size was unaffected by drug treatments. The increased LV end-diastolic pressure observed in MI rats was prevented by losartan and remained unchanged following administration of spironolactone or hydralazine. 7. Losartan prevented RV and LV hypertrophy, as well as collagen proliferation in both ventricles, after MI. The postinfarction hypertrophy observed in RV and LV after MI remained unchanged in infarcted groups treated with spironolactone or hydralazine. 8. The OH-Pro concentration was significantly reduced in LV muscle in the MI group treated with spironolactone (682 ± 40 vs 557 ± 21 µg/g for MI vs MI + spironolactone, respectively; P < 0.05), an effect not observed in the hydralazine-treated group. 9. These data suggest that spironolactone prevents collagen proliferation in the surviving myocardium by mechanisms independent of the loading conditions of the heart chambers. Control of postinfarction hypertrophy and collagen accumulation produced by losartan seems to depend on the reduction in loading conditions of the heart chambers. [ABSTRACT FROM AUTHOR]