Effect of long-term alcohol intake on the cardiovascular system of the rat

A group of rats was fed on control liquid diet, while another group was fed on liquid diet containing alcohol up to 36% of the total calories. After 4, 8 and 12 weeks of treatment ECG, haematocrit, histological structure of the heart, blood pressure, cardiac output, distribution of the organ fraction of cardiac output (by Sapirstein's method and 85Sr labelled microsphere technique), nutritive blood flow and circulatory resistance of the organs were studied. A mild repolarization disturbance was shown by the ECG record of the alcohol exposed animals. Haematocrit values and the histological structure of the heart did not change in any of the groups. Relative heart weight increased, blood pressure, total peripheral resistance and nutritive blood flow of the myocardium decreased, while myocardial vascular resistance increased. There was no significant interaction between the effects of alcohol and the duration of exposure to alcohol for any of the parameters monitored. It is concluded that chronic alcohol intake should be taken into consideration in aetiology of ischaemic heart disease.     

Effect of foreign innervation on the androgen-sensitive levator ani muscle of the rat

Summary Cross-union of the tibial with the pudendal nerve innervating the androgen-sensitive levator ani (LA) muscle of male rats, results in reversal of the histochemical muscle fibre pattern concerning myofibrillar ATPase, succinate dehydrogenase and phosphorylase enzyme activities. The homogeneous muscle fibre pattern of the LA muscle is changed to a mosaic pattern of muscles normally innervated by the tibial nerve. The success of the hetero-reinnervation is shown by practically full recovery of muscle weight and of isometric twitch-contraction properties of the LA muscle. Castration of 2-months duration, i. e. lack of the male sex hormone, leads to marked atrophy but no change in histochemical muscle fibre pattern. Hetero-reinnervation of the LA muscle results in change of histochemical enzyme pattern even if the cross-union of nerves is performed after long periods of castration leading to very marked decrease of muscle fibre size. However, testosterone application alone after castration increases markedly muscle fibre size but does not lead to reversal of muscle fibre pattern. The myotropic hormonal influence on the target (LA) muscle is therefore primarily of myogenic origin and specificity of hormonal action is maintained even with a foreign nerve innervating the muscle. The experiments, thus, provide evidence for the differentiation of specific neural influences affecting muscle fibre pattern and hormonal influences in respect to the myotropic action of the sex hormone on the androgen-sensitive LA muscle.     

Study on the water intake of rat during long-term inhalation of diesel exhaust]

To determine the chronic toxicity of diesel exhaust, F 344 rats were made to inhale various dilutions of exhaust under specific pathogen-free conditions for 16 hours a day, 6 days a week for 30 months. Five experimental groups of 240 rats each were set up, each consisting of equal numbers of rats of the both sexes of five weeks-old. During the experiment, they were housed in inhalation chambers, which were maintained at 23 +/- 2 degrees C and 55 +/- 10% relative humidity with artificial lighting 12 hours a day. Daily water intakes of all rats in inhalation chambers during the period of flow of fresh air with lights on and the period of inhalation of exhaust with lights off were measured with a drip meter fitted to automatic watering system in each inhalation chamber throughout the experiment. Result was that the mean daily water intake of the 0.5 mg/m3 (lowest particulate concentration level), 1.0 mg/m3, 1.8 mg/m3, and 3.7 mg/m3 (highest particulate concentration level) groups were 15%, 24%, 27%, and 39% less than that of the control group. Moreover, the groups also showed dose-dependent decrease in hourly water intake during the period of inhalation of diesel exhaust with lights off and dose-dependent increase in that during the period of flow of fresh air with lights on. This finding suggested that diesel exhaust might affect the circadian rhythm of the water intake in rats. These results showed that the measurement of the water intake of rat is an useful parameter to detect the biological effect on inhalation experiment.     

游泳训练后大鼠心肌细胞cAMP、cGMP含量的变化

目的:探讨游泳训练后大鼠心肌环磷酸腺苷(cAMP)、环磷酸鸟苷(cGMP)含量的变化。方法:用心脏重量(mg)/体重(g)计算心脏系数,放射免疫法测定心肌cAMP、cGMP含量。结果:8周游泳训练导致心脏系数显著增高(P<0.05),心肌cAMP水平升高不显著(P>0.05),cGMP水平显著升高(P<0.05)。结论:8周游泳训练导致心脏代偿性肥大,cAMP/cGMP比值减小。     

Effect of beta-adrenoagonists on peroxidation of lipids in the myocardium of the rat

The intravenous 80 mg/kg injection of isadrine and novodrine decreases the amount of malonic dialdehyde in the rat myocardium tissue, which is explained by the active participation of lipid peroxides of the mitochondrial matrix in the respiratory processes. Beta-adrenoagonists are supposed to promote intensive expenditure of energy and to slow down its production. They may be both antioxidants and prooxidants depending on the dose, way of administration and initial state of the material under study.     

Castration cells in rat adenohypophysis after long-term alcohol consumption

Histological and ultrastructural changes of hypophyseal gonadotropic cells of rats which received a 15% solution of ethyl alcohol for 6 months were studied. Light microscopy revealed hyperplasia and hypertrophy of these cells; some contained a vacuole of varying size. Ultrastructural analysis showed that this vacuole originated from, and anastomosed with, dilated cisternae of the granulated endoplasmic reticulum. Vacuolated cells in the pituitary of alcoholized rats were identical with cells observed after surgical or chemical castration. The development of these alcohol-induced castration cells is achieved in four stages. The first stage was characterized by beginning hydropic degeneration and other still reversible alterations. Cells in the second and third stages seemed already irreversibly on their way to decay. The fourth stage was represented by typical signet-ring cells. Our results offer a morphological basis to the adoption of a biphasic effect of alcohol on gonadotropic secretion.     

Effect of sodium intake on gentamicin nephrotoxicity in the rat.

Gentamicin nephrotoxicity was examined in rats on normal, high, and low sodium diets. Low sodium diet markedly potentiated nephrotoxic effects of the drug as evidenced by animal mortality, renal failure, pathological changes, and increased renal cortical concentration of the drug. High sodium intake reduced the cortical concentration of gentamicin but renal function and ultrastructure were similar to normally fed rats given in the same dose.     

Effect of the innervation on the structural state of F-actin in rat fast muscles

Effect of denervation and damage of the spinal cord on the structural state of F-actin in muscle extensor digitorum longus of a rat was studied by polarized microfluorimetry in the ultraviolet light region. The ability of F-actin to change its conformation at ATP binding was used as a test. The character of the changes in tryptophan polarized fluorescence induced by ATP binding was different at muscle denervation and at the damage of the spinal cord. A suggestion is made that the structural state of F-action in muscle fibres may depend on muscle innervation.     

Adrenergic innervation of the myocardium in rats with toxic exposures

Chronic intraperitoneal injection of cadmium and copper salts produces cardiotoxic effects of various degree. The degree of the muscular tissue lesion in the ventricles and atria is inverse to the number of luminescent nervous terminals. Changes in the adrenergic fibers are accompanied with certain metabolic shifts in the muscular tissue of the heart; this is evident from decreasing succinate dehydrogenase activity in cardiomyocytes and accumulation of lipids. Certain disorders are also revealed in cardiomyocytes, in vessels and in interstitial connective tissue demonstrated as: plethora, phenomena of stasis in the capillary bed, moderate perivascular edema, myocardial dystrophy. The foci of lesions are found more often in the left ventricle in myocardial tissue and under epicardium, sometimes near plethoric vessels and less often in the right ventricle and in the atria. The dependence between location of the myocardial lesions and vascular disorders is not always noted. This is observed more often under effect of cadmium sulfate and, evidently, is dependent not only on hypoxia, connected with congestive plethora, but with neurohumoral influences, too.     

Effect of alcohol on the rat juxtaprostatic pelvic ganglia and gonads

In the present paper, it was investigated the aspect of the intrapelvic autonomic neuronal system (juxtaprostatic ganglion) and gonads of rats submitted to a experimental alcoholism. The animals which had water substituted for 35% sugar cane spirit for 30 d, presented testicular lesions as well as numeric and degenerative alterations in the juxtaprostatic pelvic ganglia neurons.