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Growing evidence has highlighted that angiotensin-converting enzyme (ACE)-inhibitors (ACEi)/AT1 receptor blockers (ARBs) may influence the complex interplay between dopamine and the renin-angiotensin system in the nigrostriatal pathway, thus affecting the development of levodopa-induced dyskinesia in Parkinson's disease (PD). In the present study, we analyzed whether the use of this class of medication was associated with a reduced occurrence of levodopa-induced dyskinesia, using electronically-stored information of idiopathic PD patients enrolled at Novara University Hospital “Maggiore della Carità". We conducted a retrospective case-control study identifying PD patients with dyskinesias (PwD; n = 47) as cases. For each PwD we selected a non-dyskinetic control (NoD), nearly perfectly matched according to sex, Unified Parkinson's Disease Rating Scale (UPDRS) part III score, and duration of antiparkinsonian treatment. Binary logistic regression was used to evaluate whether dyskinesias were associated with ACEi/ARBs use. Ninety-four PD patients were included, aged 72.18 ± 9 years, with an average disease duration of 10.20 ± 4.8 years and 9.04 ± 4.9 years of antiparkinsonian treatment. The mean UPDRS part III score was 18.87 ± 7.6 and the median HY stage was 2. In the NoD group, 25 (53.2%) were users and 22 (46.8%) non-users of ACEi/ARBs. Conversely, in the PwD group, 11 (23.4%) were users and 36 non-users (76.6%) of this drug class (Pearson chi-square = 8.824, P = 0.003). Concerning general medication, there were no other statistically significant differences between groups. After controlling for tremor dominant phenotype, levodopa equivalent daily dose, HY 3-4, and disease duration, ACEi/ARBs use was a significant predictor of a lower occurrence of dyskinesia (OR = 0.226, 95% CI: 0.080-0.636, P = 0.005). Therefore, our study suggests that ACEi/ARBs may reduce levodopa-induced dyskinesia occurrence and, thanks to good tolerability and easy management, represent a feasible choice when dealing with the treatment of hypertension in PD patients. The study was approved by the Ethics Committee of Novara University Hospital “Maggiore della Carità” (CE 65/16) on July 27, 2016.

In the present work, a facile and efficient route for the synthesis of a series of N-substituted imidazole derivatives is described. Docking studies have revealed that N-substituted imidazole derivatives based on (E)-urocanic acid may be potential antihypertensive leads. Therefore, new AT1 receptor blockers bearing either the benzyl or the biphenylmethyl moiety at the N-1 or N-3 position, either the (E)-acrylate or the propanoate fragment and their related acids at the C-4 position as well as a halogen atom at the C-5 position of the imidazole ring, were synthesized. The newly synthesized analogues were evaluated for binding to human AT1 receptor. The biological results showed that this class of molecules possesses moderate or no activity, thus not always confirming high docking scores. Nonetheless, important conclusions can be derived for their molecular basis of their mode of action and help medicinal chemists to design and synthesize more potent ones. An aliphatic group as in losartan seems to be important for enhancing binding affinity and activity.

In the present work, a facile and efficient route for the synthesis of a series of N-substituted imidazole derivatives is described. Docking studies have revealed that N-substituted imidazole derivatives based on (E)-urocanic acid may be potential antihypertensive leads. Therefore, new AT1 receptor blockers bearing either the benzyl or the biphenylmethyl moiety at the N-1 or N-3 position, either the (E)-acrylate or the propanoate fragment and their related acids at the C-4 position as well as a halogen atom at the C-5 position of the imidazole ring, were synthesized. The newly synthesized analogues were evaluated for binding to human AT1 receptor. The biological results showed that this class of molecules possesses moderate or no activity, thus not always confirming high docking scores. Nonetheless, important conclusions can be derived for their molecular basis of their mode of action and help medicinal chemists to design and synthesize more potent ones. An aliphatic group as in losartan seems to be important for enhancing binding affinity and activity. [ABSTRACT FROM AUTHOR]

Background. The mechanisms of uraemia-induced atherosclerosis have not been fully delineated. The aims of this study were (i) to investigate the extent and the phenotype of atherosclerosis, including the activation of local renin–angiotensin system (RAS), in a mouse model of mild uraemia and (ii) to determine the effects of angiotensin II type1 (AT1) receptor blockade on the uraemic atherosclerosis, clarifying the mechanisms of its action.Methods. Mild uraemia was induced by 5/6 nephrectomy in 8-week-old apo E-deficient mice (apoE-KO). After nephrectomy, the animals received either treatment with candesartan or no treatment for 12-weeks. Sham-operated apoE-KO mice were used as controls.Results. Uraemia led to a two-fold increase in aortic plaque area. This was associated with a significant upregulation of aortic angiotensin-converting enzyme (ACE), AT1 receptor, connective tissue growth factor (CTGF), monocyte chemoattractant protein (MCP)-1 and vascular cell adhesion molecule (VCAM)-1. Candesartan significantly reduced aortic atherosclerosis, prevented the upregulation of the uraemia-induced genes and led to changes predicting greater stability of the plaques, without influencing blood pressure or serum lipids.Conclusions. This study indicates that uraemia leads to an acceleration of aortic atherosclerosis. The upregulation of aortic RAS and the reduced atherosclerosis following AT1 receptor blocker treatment highlights the pivotal role of the local RAS in the development and acceleration of atherosclerosis in uraemia. [ABSTRACT FROM AUTHOR]

The angiotensin II (type 1) (AT1) receptor mediates many biological effects of the renin–angiotensin system (RAS), leading to remodelling of cardiac tissue. The present study was designed to analyse changes in the function and expression of the AT1 receptor as principal effector of the RAS in myocardium from type 2 diabetic patients compared with non-diabetic myocardium as control. In addition, we determined the effect of treatment with ACE inhibitors or AT1 receptor blockers on expression levels of the receptor in diabetic patients. Gene expression of the AT1 receptor was analysed by quantitative RT-PCR and protein expression was determined by immunoblot analysis in human right atrial myocardium. We investigated functional coupling of the receptors by measuring contractility in isolated trabeculae stimulated with increasing concentrations of angiotensin II. Diabetic myocardium showed a significant increase in protein expression (170 ± 16% of control) and median mRNA expression (186% of control) of the AT1 receptor. The additional receptors were functionally coupled, resulting in a stronger inotropic response upon stimulation with angiotensin II (89 ± 5.5% vs 29 ± 1.6% in controls), whereas receptor affinity was similar in both groups. However, myocardium from diabetic patients treated with ACE inhibitors or AT1 receptor blockers showed no increase in AT1 receptor expression. AT1 receptor expression in myocardium of type 2 diabetic patients is dynamic, depending on the level of glycaemic control and the activity of the RAS. These findings could at least in part explain the strong therapeutic benefit of RAS inhibition in diabetic patients. [ABSTRACT FROM AUTHOR]

Growing evidence has highlighted that angiotensin-converting enzyme (ACE)-inhibitors (ACEi)/AT1 receptor blockers (ARBs) may influence the complex interplay between dopamine and the renin-angiotensin system in the nigrostriatal pathway, thus affecting the development of levodopa-induced dyskinesia in Parkinson's disease (PD). In the present study, we analyzed whether the use of this class of medication was associated with a reduced occurrence of levodopa-induced dyskinesia, using electronically-stored information of idiopathic PD patients enrolled at Novara University Hospital "Maggiore della Carità". We conducted a retrospective case-control study identifying PD patients with dyskinesias (PwD; n = 47) as cases. For each PwD we selected a non-dyskinetic control (NoD), nearly perfectly matched according to sex, Unified Parkinson's Disease Rating Scale (UPDRS) part III score, and duration of antiparkinsonian treatment. Binary logistic regression was used to evaluate whether dyskinesias were associated with ACEi/ARBs use. Ninety-four PD patients were included, aged 72.18 ± 9 years, with an average disease duration of 10.20 ± 4.8 years and 9.04 ± 4.9 years of antiparkinsonian treatment. The mean UPDRS part III score was 18.87 ± 7.6 and the median HY stage was 2. In the NoD group, 25 (53.2%) were users and 22 (46.8%) non-users of ACEi/ARBs. Conversely, in the PwD group, 11 (23.4%) were users and 36 non-users (76.6%) of this drug class (Pearson chi-square = 8.824, P = 0.003). Concerning general medication, there were no other statistically significant differences between groups. After controlling for tremor dominant phenotype, levodopa equivalent daily dose, HY 3-4, and disease duration, ACEi/ARBs use was a significant predictor of a lower occurrence of dyskinesia (OR = 0.226, 95% CI: 0.080-0.636, P = 0.005). Therefore, our study suggests that ACEi/ARBs may reduce levodopa-induced dyskinesia occurrence and, thanks to good tolerability and easy management, represent a feasible choice when dealing with the treatment of hypertension in PD patients. The study was approved by the Ethics Committee of Novara University Hospital "Maggiore della Carità" (CE 65/16) on July 27, 2016., Competing Interests: None

• Series of new AT 1 antagonists were designed and synthesized. • 1g and 2a could lowered the blood pressure of SHR obviously over 24 h in vivo. • 1g and 2a may be considered as potent and long-lasting anti-hypertension drug candidates. A series of new fluoro-substituted benzimidazole derivatives were designed, synthesized and pharmacologically evaluated. All the target compounds were characterized by 1HNMR, 13CNMR, mass spectra and elemental analysis. The biological evaluation showed that most of the synthesized compounds displayed nanomolar affinity to the angiotensin II type 1 (AT 1) receptor and could decrease blood pressure efficiently in spontaneously hypertensive rats. The maximal response of mean blood pressure (MBP) lowered 74.5 ± 3.5 mmHg (1g) and 69.2 ± 0.9 mmHg (2a) at 10 g/kg after oral administration, and the antihypertensive effect lasted beyond 24 h, which performed better than both losartan and telmisartan. So, compounds 1g and 2a may be considered as potential antihypertension drug candidates. [ABSTRACT FROM AUTHOR]

In this review, we discuss the pharmacological and clinical properties of irbesartan, a noncompetitive angiotensin II receptor type 1 antagonist, successfully used for more than a decade in the treatment of essential hypertension. Irbesartan exerts its antihypertensive effect through an inhibitory effect on the pressure response to angiotensin II. Irbesartan 150-300 mg once daily confers a lasting effect over 24 hours, and its antihypertensive efficacy is further enhanced by the coadministration of hydrochlorothiazide. Additionally and partially beyond its blood pressure-lowering effect, irbesartan reduces left ventricular hypertrophy, favors right atrial remodeling in atrial fibrillation, and increases the likelihood of maintenance of sinus rhythm after cardioversion in atrial fibrillation. In addition, the renoprotective effects of irbesartan are well documented in the early and later stages of renal disease in type 2 diabetics. Furthermore, both the therapeutic effectiveness and the placebo-like side effect profile contribute to a high adherence rate to the drug. Currently, irbesartan in monotherapy or combination therapy with hydrochlorothiazide represent a rationale pharmacologic approach for arterial hypertension and early-stage and late-stage diabetic nephropathy in hypertensive type II diabetics.