Histologic and histochemical changes in the aorta and myocardium of rats under the influence of atherogenic diet and phosphatidylcholine (EPL).

The prophylactic and therapeutic action of EPL on arteriosclerotic changes induced with fat-rich diet in the aorta and myocardium of white rats was studied. Histologic and histochemical studies showed that EPL administered prophylactically in doses of 280 mg/kg and 900 mg/kg body weight does not significantly inhibit development of arteriosclerotic lesions if fat-rich diet is continued. A distinct prophylactic action of EPL was first seen at a dosage of 2800 mg/kg. The therapeutic action of EPL on pathologic changes in the blood vessels also depends on dosage. The higher the dosage of EPL, the less pronounced the changes. At a dosage level of 2800 mg/kg, changes are slight and sporadic.     

Scanning and transmission electron microscopic study on the cerebral arterial endothelium of experimentally hypertensive rats fed an atherogenic diet

In order to clarify the roles of hypertension and hypercholesterolemia in atherogenesis, the cerebral arterial endothelium of experimentally hypertensive female rats fed an atherogenic diet were investigated by scanning and transmission electron microscopy. The hypertension was induced by constriction of the bilateral renal arteries. In both hypertensive groups, group I (hypertension + hypercholesterolemia) and group III (hypertension), many endothelial cells covered with numerous microvillous projections were observed. Pinocytotic vesicles and caveolae were also increased in these endothelial cells. On the other hand, in group II loaded with only hypercholesterolemia, microvillous projections on the endothelial cells tended to be increased, but its grade seemed to be lower than those of the hypertensive groups. These findings suggest that hypertension appears to be more effective than hypercholesterolemia in the cause of the increase of microvilli on the endothelial cell surfaces and the increase may be related to increased permeability in the cerebral arteries.     

Non-arteriosclerotic lesions in the kidneys of dogs fed an atherogenic diet

Hyperlipidemia was induced and sustained in a group of five dogs by feeding them a semi-synthetic diet containing 5% cholesterol and 16% hydrogenated coconut oil for 14 months. Extensive lipidosis was observed in renal tubules and collecting ducts, and degenerative and fibrotic changes were observed in glomeruli. No lipid deposits or atherosclerotic changes were seen in intrarenal arteries, despite the presence of widespread atherosclerosis in the aorta and iliac arteries. The glomerular changes consisted of hypercellularity, swelling of the mesangial stalk, adhesions between the tuft and the capsule and fibrosis of periglomerular tissue. Electron microscopy showed that these glomerular changes were associated with nodular thickenings and vacuolations of the glomerular basement membrane and fusion of the glomerular epithelial foot-processes. The cytoplasm of the proximal tubule cells was disrupted by numerous lipoid vesicles and inclusions. A control group of eight dogs fed a similar diet without cholesterol and supplemented with essential fatty acids showed none of these changes.Measurements of the clearance of endogenous creatinine and of the rate of disappearance from plasma of [¹³¹I]Iodohippurate showed that both glomerular and tubular function were severely depressed in dogs fed the cholesterol and hydrogenated coconut oil diet when compared to dogs fed a normal diet. The results indicate that significant morphological and functional changes may be brought about in the canine kidney by dietary-induced hyperlipidemia, in the absence of any renal ischemia.     

Effect of an atherogenic diet on age differences in cholesterol biosynthesis in the rat liver

After intraperitoneal injection of radioactive sodium acetate into rats of two age groups (6–8 and 28–32 months) the dynamics of cholesterol biosynthesis in the liver was observed to be slower in the older animals. The specific liver cholesterol activity of the older rats was lower at the maximum of uptake of the label than in the younger rats. An atherogenic diet for 20 days (0.25 g cholesterol/100 g body weight) led to an increase in the total cholesterol content but to inhibition of its biosynthesis in the liver, and this effect was most marked in the younger rats. Continued administration of cholesterol depressed its biosynthesis still more, especially in the older animals.Laboratory of Pathophysiology, Institute of Gerontology, Academy of Medical Sciences of the USSR, Kiev. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Gorev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 150–151, February, 1977.     

Effect of atherogenic diet on blood cholesterol and bile secreting function of the liver of rats of different ages

After isolation of the common bile duct the quantity of bile secreted during 24 h and the concentration of total bile acids in it were determined in adult (11–12 months) and old (27–29 months) rats. Differences between the adult and old rats as regards bile formation and the concentration of the cholesterol fractions of the liver and blood plasma were not significant if the animals were kept on a standard diet. If kept on an atherogenic diet, the secretion of bile acids was significantly higher both in the adult and in the old rats. Meanwhile the level of total and esterified cholesterol in the blood plasma was higher in the old than in the adult rats.Research Institute of Physiology, Kiev University. Laboratory of Pathological Physiology, Institute of Gerontology, Academy of Medical Sciences of the USSR. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Gorev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 2, pp. 155–157, February, 1978.     

Depolymerization of fibrin and nonenzymic fibrinolysis in rabbits on an atherogenic diet with added antioxidants

Laboratory of Physiology and Biochemistry of Blood Clotting, Moscow State University. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 10, pp. 419–421, October, 1990.     

Long term lathyrism and atherogenic diet in the rat

Summary In the rat, prolonged administration (7 months) of Beta-Amino-propionitrile in association with a hyperlipidic diet caused the formation of widespread pronounced atheroma. The addition of Pyridinol Carbamate during the treatment minimized and retarded the appearance of lipid overload lesions.The histological modifications were found together with an increase in the free cholesterol fraction. These two observations explain the protective role of Pyridinol Carbamate on the wall of the aorta.Chargée de Recherche CNRS     

Histochemical and morphological observations on rat myocardium after exercise

Effects of seven levels of chronic physical activity on the metabolic and morphologic characteristics of left ventricular myocardium of adult male albino rats were investigated.Treatments included sedentary control; voluntary running; short-duration, high-intensity running; medium-duration, moderate-intensity running; long-duration, low-intensity running; electric stimulus control; and endurance swimming. Excluding the controls, the animals were trained 5 days per week for 8 consecutive weeks. Food and water were providedad libitum to them. Fifty-six animals comprised the final sample.Histochemical techniques were used to evaluate the relative glycogen, fatty acid, SDH and LDH concentrations in the cardiac fibers. Each stain was measured objectively, using a photometer. A Hematoxylin and Eosin stain was employed to rate morphologic features. These sections were evaluated subjectively on the basis of presence or absence of lesions.Physical training for 8 weeks was sufficient to produce metabolic adaptations in the rats. The trained animals gained 37.4 % less body weight than did the sedentary controls (P < 0.05). However, neither histochemical nor morphological changes had occurred to the hearts of these animals consequent to the 8 weeks training programs. Apparently, the myocardial tissues examined, from the trained animals, contain the enzymes, SDH and LDH, and the substrates, glycogen and fatty acids, in amounts greater than that needed to cope with the exercise stress afforded by these training programs.