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In the dog testicular interstitial cells the cytoplasmic filaments are occasionally arranged in large bundles piled closely in an extensive area adjacent to the Golgi region in the cytoplasm. Some of the large bundles show conspicuous circular or spiral configurations which are composed of elaborate arrangements of both circular and longitudinal filaments and accompany tubules of agranular endoplasmic reticulum running parallel to the longitudinal filaments. [ABSTRACT FROM AUTHOR]

Electrical stimulation of the tooth of the dog has demonstrated that δ-tetrahydrocannabinol (1 mg/kg) produces analgesia. Daily administrations cause tolerance to this effect in 8 days. The nature of the analgesia induced by THC is discussed. [ABSTRACT FROM AUTHOR]

Intravenous self-administration of morphine by dogs was studied before and during dependence on morphine, and after 1 to 6 months of enforced abstinence. In comparison to pedal response rates during a saline control period, 18 of 22 dogs studied showed decreased rates of responding for morphine during the initial 3-week exposure. Following subsequent passive establishment of dependence in 7 dogs, they self-administered morphine and maintained dependence. Following enforced abstinence for periods of 1 to 6 months the 7 dogs relapsed to self-administration of morphine when it was again made available. In contrast, additional dogs offered food or amphetamine reinforcements showed marked increases in pedal responding for these reinforcements within a few days after initial exposure. The results indicate that in post-dependent dogs that had maintained their dependence on morphine by self-administration, effects other than those experienced during the initial exposure to morphine are responsible for relapse. [ABSTRACT FROM AUTHOR]

The arterial and venous oxygen parameters were measured during 3 h in fifteen air-ventilated dogs injected intraperitoneally (100 ml/kg) with different solutions. Three groups were studied: 1. control (C); 2. water depleted (WD); 3. water and salt depleted (WSD). The WSD showed lower mixed venous O content, saturation and pH and greater (A-V) O rate of change than the WD. Comparable $$P_{\upsilon {\text{o}}_2 } $$ changes were recorded. About half of these modifications could be explained on the basis of the increased intra-abdominal pressure with resulting venostasis (Jach, Marotta and Marbarger, 1959). The plasma volume decrease, comparable in the WD and WSD, accounts for the largest changes observed in the oxygen parameters probably due to the resulting decrease in cardiac output and low blood flow in these animals. The Bohr effect might explain why in spite of comparable $$P_{{\text{o}}_3 } $$ values the mixed venous O content and saturation, and arterial hemoglobin O saturation values are lower in WSD than in WD. [ABSTRACT FROM AUTHOR]

Blood flow in the vena cava was measured in anesthetized dogs in supine, lateral, or prone position by a catheter velocity probe at four levels, i. e., above and below the veno-atrial junction and above and below the confluence of the renal veins, with the diameter of the vena cava fixed Teflon rings placed around it. Also the influence of pneumoperitoneum at atmospheric pressure on venous return was examined in supine position. In supine position there was an increase of venous return in the thoracic venae cavae and of calculated hepatic outflow during inspiration, whereas flow in the abdominal vena cava showed less and reversed variations as compared with the thoracic inferior caval venous pattern, i.e., a trough during inspiration and a peak during early expiration. Pneumoperitoneum reduced the inspiratory increase of thoracic inferior vena cava flow and of hepatic outflow. Lateral and prone positions induced a decrease or early leveling off of the inspiratory increase of flow in the thoracic inferior vena cava and of hepatic outflow. Superior caval venous flow remained almost unchanged with postural change. In all positions renal outflow did not show any clear-cut relationship with respiration. These variations of pattern of vena cava flow and hepatic outflow were attributed to an increase in the resistance of the vena cava in the infradiaphragmatic part, induced by the change of body position, as shown by an increase of the preinspiratory caval venous pressure difference between thorax and abdomen to 5.3±0.92 cm HO (mean±S.D., n=14) in lateral position, and to 6.5±0.81 cm HO ( n=4) in prone position from 2.0±0.85 cm HO ( n=18) in supine position ( p<0.001 for the increase from supine position). [ABSTRACT FROM AUTHOR]

Moment-to-moment variation of effective alveolar $$P_{O_2 } $$ ( $$P_{Ae_{O_2 } } $$ ) during the respiratory cycle was calculated based on a two-alveolar lung model in dogs anesthetized and pump-ventilated under various conditions induced by continuous infusion of sympathomimetics. Under fixed ventilation the amplitude of respiratory fluctuation of $$P_{Ae_{O_2 } } $$ (Δ $$P_{Ae_{O_2 } } $$ ) increased with $$\dot V_{O_2 } (\Delta P_{Ae_{O_2 } } = 0.774 \cdot \dot V_{O_2 } + 1.862;p< 0.001)$$ while Δ $$P_{Ae_{O_2 } } $$ did not show any correlation with V/ V or with the fraction of effective alveoli. Ideal alveolar $$P_{O_2 } (P_{Ai_{O_2 } } )$$ in the same situation was near the peak of fluctuating $$P_{Ae_{O_2 } } $$ , thus higher than mean effective alveolar $$P_{O_2 } (P_{\overline {Ae} _{O_2 } } )$$ by about 4 to 5 mm Hg. This difference of $$P_{Ai_{O_2 } } $$ and $$P_{\overline {Ae} _{O_2 } } $$ might be attributed to the difference in respiratory pattern, i.e., constant one-way flow as against periodic ventilation. [ABSTRACT FROM AUTHOR]

The amplitudes of respiratory oxygen fluctuations in the alveoli obtained by calculation were compared with those of the arterial blood measured by a catheter P electrode in vivo in anesthetized and artificially ventilated dogs. It is shown that there is a significant correlation between them in general in both P and S though the latter correlates better. Amplitude ratio of arterial to alveolar O fluctuations was calculated from two factors, i.e., dispersion of circulation time in the pulmonary vein and mixing in the left heart. The results of calculation agree satisfactorily with those obtained experimentally. The reduction of the amplitude of respiratory fluctuations of oxygen seems to be quite small in the aorta. [ABSTRACT FROM AUTHOR]

If injected into the superior pancreatico-duodenal artery secretin, pancreozymin, histamine and Decholin each significantly increases the amount of blood flowing through the artery and the pancreatic tissue. The relationship between the logs of the drug doses and their effects are linear. Whereas to histamine and Decholin all dogs respond with the same rise in pancreatic blood flow, to pancreozymin the rate of increase was similar in all dogs and to secretin the rate of increase differs from one animal to the other. [ABSTRACT FROM AUTHOR]

Dogs were depleted of water (3.5% BW) and salt (about 10% of their total body exchangeable sodium) by intraperitoneal injection of a 10% glucose solution (550 mOsm/l). During the 3-h experiment these water and salt depleted (WSD) animals showed a significant decrease in blood pH, base excess (BE), plasma bicarbonate (HCO), systolic (SP) and diastolic (DP) pressures and an increase in both Ht and blood buffer capacity (BBC). pH and BE changes were linearly correlated with time whereas the remaining parameters showed a better regression line with log time. The acid-base changes were dependent on both plasma volume ratio (PVR) and hemodynamic changes, the latter being ascribed to the plasma volume decrease. Increased endogenous acid production related to both hemodynamic hypoxia and redistribution of cellular fluid is suggested as the mechanism explaining blood acid-base changes. [ABSTRACT FROM AUTHOR]

Heart rate (HR), respiratory rate (RR), blood pressure (BP). and motor components of responses to non-reinforced and reinforced auditory stimuli were studied in six dogs over a period of 20 months. The experiment consisted of several phases: habituation, orienting training, conditioning, extinction, and reconditioning. Differentiated non-specific motor reactions in four of six dogs developed quickly and before the differentiated specific motor conditioned response (CR) and consistent HR or BR conditioned responses. The form of the gross organismic CR pattern differed in each dog. Yet the animals reliably maintained, in each separate system, their rank-order positions across experimental phases, suggesting that the CR is determined in part by innate or earlier acquired differences in functioning. [ABSTRACT FROM AUTHOR]

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Dogs were conditioned to respond to cutaneous stimulation of either hindlimb by a forelimb movement in order to test the function of various pathways in the spinal cord. After maximum performance had been achieved in the preoperative training chronic lesions were made at low thoracic level and the effect determined in postoperative testing. After transection of the dorsal part of the lateral funiculus (DLF) on one side to interrupt the spinocervical tract a transient impairment of reflexes elicited by light tactile (puffs of air) stimuli from that side was observed. No changes of the reflexes were observed after unior bilateral transections of the dorsal columns. However, a dorsal column transection performed secondarily to a unilateral DLF transection, or vice versa, severely impaired, sometimes permanently, the conditioned reflexes to light tactile stimuli from the side of the combined DLF and dorsal column transection. Conditioned reflexes elicited by a coarse (50 Hz electric current) cutaneous stimulus were unaffected by DLF and dorsal column transections, whether single or in combination. It is concluded that the main spinal afferent pathway of the conditioned reflexes to light tactile stimuli is the spinocervical tract and that the dorsal column pathway probably is of secondary importance. The reflexes elicited by the coarse cutaneous stimulus do not depend primarily on either pathway. [ABSTRACT FROM AUTHOR]

Evoked potentials from stimulation of the hindlimbs were recorded in the cerebral somatosensory areas of dogs using Nembutal anaesthesia. Various transections of the low thoracic spinal cord were made in order to determine the pathways projecting to these areas. The shortest latency cortical activation was obtained via two pathways: the dorsal column pathway and the spinocervical tract which is located in the dorsomedial part of the lateral funiculus (DLF). Cortical activation after longer latency was obtained via ventral pathways in both the contralateral and ipsilateral spinal halves. The cortical potentials elicited by adequate (hair) stimuli depended mainly on transmission via the dorsal column and DLF pathways. [ABSTRACT FROM AUTHOR]

The parenchymal cells of the pars distalis of the dog adenohypophysis were studied with the electron microscope. Criteria for the differentiation of four cell types included the size and shape of the cells and the size, shape and distribution of organelles and secretory granules. Three secretory granule-containing cells designated as I, II and III were observed. Cell type I was further divided into subtypes (Ia, Ib, Ic) on the basis of the granule size of maximal frequency. A fourth cell type (IV) contained no or only a few secretory granules. It was unique in having a highly irregular shape with cytoplasmic processes extending between the other cell types and also occasionally enclosing follicular cavities. [ABSTRACT FROM AUTHOR]

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The systemic and coronary hemodynamic effects of the new antihypertensive agent L 6150 (3-hydrazino-6-[N,N-bis(2-hydroxyethyl) amino]pyridazine) have been investigated in anesthetized and unanesthetized dogs, in comparison with hydralazine. The depressor effect induced by L 6150 is due to a fall of peripheral resistance and, in conscious animals, is accompanied by an increase of cardiac output and heart rate, suggesting that the main activity of the drug is related to a vasodilator effect. The compound was shown to markedly increase coronary blood flow. This effect, which in conscious dogs can be explained, at least in part, on the basis of an increased myocardial metabolism, was observed to occur in anesthetized animals even in conditions of reduced cardiac output and myocardial oxygen consumption. In anesthetized dogs the same systemic, hemodynamic modifications were induced by L 6150 and by higher doses of hydralazine. Furthermore the percent increase of coronary blood flow induced by L 6150 was significantly higher than that induced by hydralazine, for the same degree of modifications of myocardial oxygen uptake. In conscious dogs, L 6150 induced the same systemic hemodynamic modifications as hydralazine with the exception of heart rate, which was increased more by the former drug. The coronary blood flow increase was more marked following L 6150 than following hydralazine, even when the two drugs induced the same increase of cardiac output. [ABSTRACT FROM AUTHOR]

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The innervation of the dog's parotid has been studied by cholinesterase staining and catecholamine fluorescence. In normal glands cholinergic and adrenergic nerves are plentiful around acini, muscular blood vessels, and to a lesser extent striated ducts. The main ducts, although surrounded by many cholinesterase-positive nerves, are associated with few adrenergic nerves. Severance of the 'classical' parasympathetic post-ganglionic nerve to the gland, the auriculo-temporal, caused a moderate loss of cholinesterase-positive nerves. When this procedure was combined with section of the nerves on the internal maxillary artery there was a greater loss. Fewest cholinesterase-positive nerves remained when, in addition to these two procedures, the facial nerve was cut. These findings support the concept that all three sets of nerves contain some post-ganglionic parasympathetic fibres for the dog's parotid. The source of the remaining nerves is unknown. Preganglionic parasympathetic denervation by section of the tympanic branch of the glossopharyngeal nerve did not reduce the number of cholinesterase-positive nerves. None of these parasympathetic denervations caused reduction of adrenergic nerves, indicating that they do not travel to the gland with the parasympathetic nerves. After superior cervical ganglionectomy a few scattered fluorescent nerves remained in the gland; their origin is unknown. [ABSTRACT FROM AUTHOR]

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Sections of the retractor penis and vas deferens of the dog have been examined to reveal the histochemical localization of noradrenaline (NA) and acetylcholinesterase (AChE) in the intrinsic nerve fibres. Pine varicose nerves containing NA were abundant along the entire length of the retractor penis muscle, while fine fibres exhibiting high AChE activity were restricted almost entirely to the anterior half of the muscle. In the testicular end of the vas deferens, a dense plexus of noradrenergic nerves was found at the base of the mucosal epithelial cells and other NA-containing nerves were scattered relatively sparsely through the muscle coats. In contrast, at the urethral end, the smooth muscle coats contained a far more dense population of NA-containing nerves, and there was no evidence of a submucosal nerve plexus. Fibres exhibiting high AChE activity were also found throughout the muscle coats, but no concentration of staining fibres was observed in the submucosa at the testicular end of the organ. It is concluded that the smooth muscle of both the retractor penis and the vas deferens of the dog may receive innervation from separate adrenergic and cholinergic fibres. Appreciable levels of AChE do not appear to be associated with adrenergic axons in this species. [ABSTRACT FROM AUTHOR]

The dose-response relationship for apomorphine-induced stereotypy in dogs is presented. A minimum effective dose is 0.2 mg/kg i.v., but the fully developed syndrome requires 0.8 mg/kg i.v. The stereotyped behaviour following the supramaximal dose 1.6 mg/kg i.v., mainly consisting in an incessant running activity, is described in detail. Antipsychotic neuroleptics were highly active inhibitors of the apomorphinestereotypy, whereas phenoxybenzamine, amitriptyline, anticholinergics, antihistaminics, metoclopramide and diazepam were without influence on the stereotypy. H 44/68 (α-methyltyrosine-methylester) potentiated the syndrome. In provoking stereotyped behaviour in the dog, apomorphine, as in other species, probably acts directly on dopamine receptors in the corpus striatum. Accordingly two sites of action for apomorphine may exist in the dog, the trigger zone in the area postrema for emesis, and the neostriatum for stereotypy. [ABSTRACT FROM AUTHOR]

Conditions have been established for the quantitative formation of radiolabeled derivatives of chlorpromazine, chlorpromazine sulfoxide and their demethylated analogs in plasma extracts. Tritiated N-acetyl derivatives are formed from the demethylated compounds and C-quaternary amines from the tertiary amines by acetylation and methylation, respectively. These reactions are quantitative over a wide range of concentrations. The reactions may be performed sequentially when chloropromazine and its Nor derivatives (or chlorpromazine sulfoxide and its Nor derivatives) exist in a single extract. Herein, the mixture is first acetylated and subsequently methylated. The labeled derivatives are quantitatively separated and recovered by selective solvent partition. An extraction procedure has been suggested by which chlorpromazine and its Nors may be separated from chlorpromazine sulfoxide and its Nor derivatives so that each fraction may be subjected to the sequential acetylation and methylation reactions. Recoveries of μg quantities of standards from plasma are less than quantitative, probably because of losses due to glass adsorption and protein binding, but may be corrected with appropriate internal standards. As low as 15-20 ng/ml of each compound are measurable in a 3 ml plasma aliquot. The method has been applied to a limited number in vivo experiments in dogs and in humans. [ABSTRACT FROM AUTHOR]

Dogs were repeatedly exposed to SO (500 ppm) in a gassing chamber. A significant increase in lung resistance and elastance as well as clinical and radiological signs similar to those seen in human chronic obstructive respiratory diseases were observed. Inflammatory changes of the bronchial mucosa and typical pictures of central-acinar emphysema were shown by histopathological examination. Improvement of lung mechanical function could be demonstrated by intravenous administration of several bronchodilator agents and mucus liquefaction was observed after inhalation of a mucolytic aerosol. [ABSTRACT FROM AUTHOR]

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Dogs were water depleted 2% of their body weight by the intraperitoneal injection of a hyperosmotic solution of saline and glucose (550 mOsm/l). During a 3-h experiment these water-depleted (WD) animals showed a significant decrease in blood pH, base excess (BE) and plasma bicarbonate (Bic) and an increase in both hematocrit (Ht) and blood buffer capacity (BBC). These changes were quantitatively time-dependent. The rate change of pH, BE, and Bic were −0.072 units h, −4.7 mEq/l h, and 2.9 mEq/l h, respectively. As control dogs showed no significant time-dependent changes in their blood acid-base status, the observed modifications in the experimental dogs were ascribed to water depletion. Increased endogenous acid production related to tissue hypoxia is suggested to be the mechanism that could explain the increased fixed acid accumulation observed in the water-depleted animals. [ABSTRACT FROM AUTHOR]

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Copyright of Zeitschrift Für Die Gesamte Experimentelle Medizin Einschließlich Experimentelle Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift Für Die Gesamte Experimentelle Medizin Einschließlich Experimentelle Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Diabetologia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Diabetologia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The triglyceride compositions of the milk fats of man, dog, guinea pig, cow, sheep, goat, and horse were compared by gas-liquid chromatography of the intact triglycerides and of the butyl esters of the component fatty acids. The milk fats of man, dog, and guinea pig, which were largely made up of long-chain fatty acids, showed a common pattern with major contributions made by the glycerides with 48-54 acyl carbon atoms. The milk fats of cow, sheep, and goat, which were rich in short-chain acids, showed significant proportions of triglycerides with 28-54 acyl carbon atoms. Horse milk, which contains large amounts of medium-chain fatty acids, gave a characteristic triglyceride pattern in the 26-54 carbon atoms range. The experimentally determined distributions of the molecular weights of the triglycerides of all milk fats deviated significantly from the distributions predicted by random association of the fatty acids from a single pool. The data suggest that in all species the milk fat may be formed by a partial resynthesis of preformed glycerides.

Lipogenesis from amino acids has been studied in isolated perfused dog skin. Uniformly labeled alanine-14C, glycine-14C, isoleucine-14C, leucine-14C, phenylalanine-14C, and valine-14C are all incorporated into the cutaneous lipids, with significant incorporation into most of the isolated lipid fractions. Efficiency of lipogenesis has been expressed relative to the extent of incorporation of acetate under the same experimental conditions. This efficiency was highest for the three branched-chain amino acids.The accuracy, uses, and limitations of the perfusion technique for the study of cutaneous lipogenesis have been evaluated.

Radioactive glycerol and Sf > 20 lipoproteins labeled with it were used to study turnover of plasma Sf > 20 and hepatic triglyceride in anesthetized dogs. From specific activity-time curves of these lipids after an injection of labeled material, a tentative and incomplete model for the kinetics of endogenous hepatic and plasma triglyceride was defined and partially validated. Pool sizes and turnover rates of triglyceride in liver and Sf > 20 lipoproteins of plasma were then calculated in seven dogs.Hepatic triglyceride was composed of two compartments: 60% metabolically inert and 40% metabolically active. Although communication between these hepatic compartments surely occurred during the time course of these studies, it was not sufficient to be detected by our present methods. The metabolically active compartment turned over as a single pool but with two destinations: a quite variable proportion (an average of 61%) was secreted into plasma as Sf > 20 triglyceride, and an average of 39% was presumably hydrolyzed within the liver.The fractional turnover rate of plasma Sf > 20 triglyceride was 2-3 times that of hepatic triglyceride. This finding, and the parallel decline of specific activities of plasma Sf > 20 and liver triglyceride after injection of labeled glycerol, confirm the rate-determining role of hepatic triglyceride. In this respect the dog differs importantly from man. Though turnover rates of plasma Sf > 20 triglyceride fell in the same range in men and dogs, the relationship of turnover rate to plasma concentration of this lipid differed greatly between them. The model for the dog does resemble that previously reported for man, however, in the lack of major recycling of intact plasma triglyceride between the liver and plasma. Lack of such recycling, however, does not exclude return of plasma triglyceride into a hepatic triglyceride sink. The amount of such unidirectional uptake, if any, could not be determined by these techniques.

Procedures are described for the isolation of free fatty aldehydes from total lipid extracts of rat, dog, and bovine heart muscle. These aldehydes did not arise from hydrolysis of the naturally occurring alkenyl ethers in either the extraction or isolation procedures.The free fatty aldehydes were present in heart muscle in amounts between 0.27 and 0.56 μmole per 100 mg of lipid.Hexadecanal and octadecanal are the principal free fatty aldehydes present, except in dog heart muscle where an unidentified, unusual aldehyde constitutes 20% of the mixture.