Effects of regulatory peptides on DNA synthesis in duodenal smooth muscle tissues of albino rats during the early postnatal period

Effects of angiotensin II, endothelin-1, dermorphin A10 analogue, dalargin, and hydra peptide morphogen on DNA synthesis in duodenal smooth muscle cells of newborn albino rats were studied by³H-thymidine autoradiography. Angiotensin II and endothelin-1 increased the number of DNA-synthesizing myocytes and did not affect the labeling intensity. Dermorphin A10 analogue, dalargin, and hydra peptide morphogen had no effect on these indexes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 6, pp. 651–653, June, 1999     

Involvement of angiotensin II system components in regulation of DNA synthesis in pyloric epithelium of albino rats

Effects of intraperitoneal injections of angiotensin II and oral intake of cosaar (angiotensin II receptor blocker) and ednite (angiotensin-converting enzyme inhibitor) on DNA synthesis in the pyloric portion of the stomach was studied in adult albino rats by autoradiography with³H-thymidine. Proliferative processes in the studied tissue were enhanced 24 h after single injection of the peptide in a dose of 50 μg/kg and 4 h after injection of 100 μg/kg peptide. Treatment with cosaar and ednite for 2 weeks led to normalization of stress-activated epithelial proliferation in the pyloric part of the stomach. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 2, pp. 214–216, February, 2000     

Effect of endothelin-1 on DNA synthesis in the myocardium of albino rats during early postnatal ontogeny

Effect of intraperitoneal injection of endothelin-1 on DNA synthesis in the myocardium of newborn albino rats was studied by³H-thymidine autoradiography. Endothelin-1 injected in a single dose of 10 μg/kg stimulated proliferative processes: the index of labeled nuclei and labeling intensity increased. Repeated (5 times) administration of endothelin-1 in doses of 1 and 10 μg/kg increased labeling intensity, but did not change the index of labeled nuclei. The data suggest that endothelins, are involved in morphogenesis of the myocardium during the early postnatal ontogeny. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 12, pp. 623–626, December, 2000     

Myocardial hypertropy in rabbits with renovascular hypertension under pharmacological blockade of angiotensin II synthesis and its interaction with specific receptors

The dynamics of blood pressure, the weight of the heart and its subdivisions, and morphology of myocardium were studied in the rabbits with experimental renovascular hypertension. Treatment with inhibitors of angiotensin II synthesis (lotensin) or its interaction with specific receptors (valsartan) decreased blood pressure and the weight of the left ventricle, but did not affect the interrelations between structural elements in the heart, which remained the same as in hypertension-induced myocardial hypertrophy. In addition, these drugs impaired some parameters of cardiac activity attesting to myocardial overload, increase in collagen content in the myocardium, and decrease in the ratio of the numbers of capillaries and mitochondria to the weight of myofibrils. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 5, pp. 506–509, May, 1999     

Effect of dynorphin A1–13 on DNA synthesis and cAMP level in the myocardium of albino rats during early postnatal ontogeny

Effect of intraperitoneally injected dynorphin A_1–13 on myocardial DNA synthesis in newborn rats was studied by³H-thymidine autoradiography. Single administration of 100 μg/kg peptide had no effects on DNA synthesis, while repeated (for 5 days) administration of the peptide significantly increased the labeling index of nuclei and labeling intensity in the myocardium 24 h postinjection. Single administration of dynorphin decreased cAMP levels in heart homogenates 4 h postinjection. Dynorphin is probably involved in the establishment of myocardial structural homeostasis. This effect is mediated by the system of cyclic nucleotides. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 7, pp. 63–65, July, 1999     

Effect of calcium channel blocker verapamil on DNA synthesis and activity of nucleolar organizer in cardiomyocytes of newborn albino rats

Fivefold administration of L-type Ca²⁺ channel blocker verapamil in a dose of 1.5 mg/kg to newborn rats increased the parameters of DNA-synthetic activity in the myocardium: labeling index and intensity increased 1.24-fold on average. Body weight decreased with simultaneous increase in the absolute and relative heart weight. Morphometric parameters of the nucleus and nucleoli were practically unaffected. Our findings suggest that the Ca²⁺ channel blocker verapamil administered at the early postnatal stages can modulate morphogenesis of the heart Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 6, pp. 658–660, June, 1999     

Alterations in cardiac function in response to epinephrine in rats with hereditary hypertension (An ECG study)

A comparative electrocardiographic evaluation of changes in cardiac function in rats with hereditary arterial hypertension (NISAG strain) and normotensive (Wistar) rats in response to a single epinephrine injection revealed much more pronounced changes in NISAG rats, including an unfavorable time course of electrocardiographic waves (left ventricle overload) and impaired conduction (blockade) and excitability (extrasystoles). The results indicate that the myocardium of NISAG rats is much more responsive to the acute stimulation of adrenergic receptors by epinephrine than is the myocardium of normotensive rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 10, pp. 372–375, October, 1995 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

Morphofunctional characteristics of connective tissue in emotionally stressed august and wistar rats

August rats, which are predisposed to emotional stress, are shown to differ from Wistar rats, which are not so predisposed, in the morphofunctional organization of lymphoid and connective tissues. In August as compared to Wistar rats, the lymphoid tissue of the spleen, trachea, bronchi, intestine, and lymph nodes is less abundant, the pancreatic insular apparatus is developed much better, and loose connective tissue contains more mast cells without signs of degranulation. Emotional stress leads, in both strains, to strong connective tissue congestion, massive hemorrhages, edema of loose connective tissue in the renal medullary substance and in the liver, focal or focal/confluent connective tissue metachromasia, and progressive mast cell degranulation. These changes are all more pronounced in August rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 571–573, June, 1995     

Dehydrogenase systems of different rat tissues in experimental alcoholism simulated by inhalation or forced intake of ethanol

It is shown that alcoholization of rats during 1.5 months by the inhalation of ethanol vapors with a long-term subsidence into narcotic sleep results in alcohol dependence and marked shifts in the ratio between the activity of malate and lactate dehydrogenases and a change in the isoenzyme spectrum of the latter. This leads to an enhancement of aerobic processes in the brain and skeletal muscle tissues and of anaerobic processes in the liver and myocardium. Semiforced alcoholization of rats during 11 months, with ethanol solution serving as the only soruce of liquid, moderately lowers the ethanol tolerance and does not affect the dehydrogenase activity in the tissues examined. The effects of ethanol on the activity of functionally associated enzyme systems of malate and lactate dehydrogenases are believed to depend on the method of alcoholization and the type of tissue. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o , 7, pp. 107–109, July, 1994 Presented by A. N. Klimov, Member of the Russian Academy of Medical Sciences     

Comparative analysis of effects from prolonged peripheral and intracerebral administrations of angiotensin II in rats

Variations in arterial pressure and food and water consumption were studied in rats during and after their prolonged continuous exposure to angiotensin II using osmotic minipumps. Subcutaneously administered angiotensin-II (300 μg over 7 days) induced long-lasting hypertension followed by hypotension. Angiotensin-II administered into a lateral cerebral ventricle (3 μg over the same period) led to a significant fall in arterial pressure. The peripheral and intracerebral angiotensin-II administrations were both accompanied by increased water consumption. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N^no 10, pp. 352–354, October, 1994 Presented by K. V. Sudakov, Member of the Russian Academy of Medical Sciences     

Effect of the hydra peptide morphogene at the early stages of rat postnatal ontogenesis

The effect of the hydra peptide morphogene, its structural fragment, and antagonist 5N pentapeptide on DNA production in the myocardium, tongue, gastric and tracheal epithelium was studied in 7-day-old rats. The hydra peptide morphogene stimulated proliferative activity of the myocardium and epithelium of different organs. 5N fragment did not affect the production of DNA in the myocardium and suppressed it in the epithelium. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 12, pp. 681–683, December, 1998     

Effects of angiotensin II on proliferative activity of epitheliocytes and smooth muscle cells of the tracheobronchial system in newborn albino rats

Angiotensin II was injected intraperitoneally in a dose of 5×10⁻⁸ mol/kg to newborn rats from then 2nd to 6th day of life. Autoradiography with³H-thymidine showed that angiotensin II stimulated DNA synthesis in epitheliocytes and smooth muscle cells of the trachea and large (cartilaginous) and small (noncartilaginous) bronchi, intensified lipid peroxidation, and activated the antioxidant defense system in the lungs.     

Effects of Angiotensin II and proliferative activity of epitheliocytes and smooth muscle cells of the tracheobronchial system in newborn albino rats

Angiotensin II was injected intraperitoneally in a dose of 5×10⁻⁸ mol/kg to newborn rats from then 2nd to 6th day of life. Autoradiography with³H-thymidine showed that angiotensin II stimulated DNA synthesis in epitheliocytes and smooth muscle cells of the trachea and large (cartilaginous) and small (noncartilaginous) bronchi, intensified lipid peroxidation, and activated the antioxidant defense system in the lungs.     

Some characteristics of the proteinase—Inhibitor systems in adaptive response to strenuous exercise

In rats, adaptation to strenuous exercise was accompanied by phasic changes in the activities of the kallikrein-kinin system, elastase-like proteinases, and proteinase inhibitors, and total antioxidant activity in the serum, myocardium, liver, and cerebral cortex. After 30-min physical exercises, activity of the kallikrein-kinin system decreased in the serum and increased in tissue with parallel activation of elastase-like proteinases in the myocardium and cerebral cortex. After 3-h exercises the activity of the kallikrein-kinin system showed some indications of exhaustion, especially in the myocardium and cerebral cortex. Activities of elastase-like proteinases tended to normal due to activation of α₁-proteinase inhibitor and normalization of total antioxidant activity. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 5, pp. 529–532, May, 1999     

Cellular mechanisms of genetically determined hypertrophic cardiomyopathy in W/SSM rats

Hypertrophic cardiomyopathy, a hereditary pathology of the myocardium, was generates in rats with genetically determined galactose metabolism. It is shown that the increase in the myocardium mass results at first predominantly from an increase in the number of cardiomyocytes and then, after exhaustion of the proliferative potential, from cardiomyocyte hypertrophy. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 11, pp. 547–551, November, 1994     

Biochemical and physiological activity of new peptide inhibitors of angiotensin converting enzyme

The physiological and biochemical activity of new angiotensin converting enzyme inhibitors is studiedin vitro (in microsomal fractions from the pituitary gland and corpus striatum) andin vivo. Compound PP-09, an N-carboxyalkyl derivative of enalapril, displaying high inhibiting activity towards rat serum and tissue angiotensin converting enzyme and lowering arterial pressure in spontaneously hypertensive rats, is selected. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No, 9, pp. 279–281, September, 1996     

Effects of ubiquinone-10 on energy metabolism and lipid peroxidation in rats with myocardial ischemia

Preventive and therapeutic intraventricular administration of ubiquinone-10 to male rats with epinephrine-induced myocarditis increased the rate of oxidative phosphorylation, elevated the content of ATP, and inhibited lipid peroxidation in ischemic myocardium. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 7, pp. 35–38, July, 2000     

Effect of μ-opiate receptor agonist tetrapeptide A10 on DNA synthesis and protein content in the myocardium of albino rats

Effect of intraperitoneal injection of tetrapeptide A10 (H-Tyr-D-Orn-Phe-Gly-OH), selective μ-opiate receptor agonist, synthetic analog of dermorphine, in a dose of 100 μg/kg on DNA synthesis and protein content in the myocardium was studied in albino rats. Five injections of tetrapeptide on days 2–6 after birth caused no changes in DNA synthesis 17 days after the last injection,i. e. in 24-day rats. The number of nucleoli and their area increased. In adult males long-term (3-week) treatment with tetrapeptide A10 increased the number of nucleoli and the mean and integral optical density of isolated cardiomyocytes stained with amido black B, which probably attested to activation of protein synthesis in the myocardium. Simultaneously, the content of catecholamines in the heart increased. These data are comparable with delayed effects of κ-opiate receptor agonist dinorphine A_1–13 and indicate that morphogenetic properties of opioid peptides in rat myocardium are realized via the same routes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 12, pp. 693–695, December, 2000     

New aspects of heparin effects

The effects of a 5-day heparin treatment (10 kD, 64 IU/kg, intraperitoneally) on food-procuring behavior and spatial memory in a 12-arm radial maze were studies on Wistar rats. The maximum reinforcement scores in heparinized rats were attained by day 7 and in control rats only by day 16. In total, 75% heparinized and 45% control rats successfully learned the task for 24 days. On day 25 the contents of major transmitters and their metabolites in various brain structures and in the small intestine of control and experimental rats were determined. The rats treated with heparin showed increased concentrations of norepinephrine in the hypothalamus, homovanillic acid in the striatum, and serotonin in the small intestine. Our findings indicate that heparin exhibits a wide range of activities in addition to its anticoagulant effect. Translated fromByulleten' Eksperimental'noi Biologii I Meditsiny, Vol. 130, No. 12, pp. 613–616, December 2000