Effect of the hydra peptide morphogen on posthypoxic disorders in rats exposed to prenatal hypoxia

Lipid peroxidation in the lungs and blood are activated while DNA synthesis in the tracheal epithelium and hepatocytes is inhibited during the first five days of postnatal life in rat pups after severe prenatal hypoxia. Intraperitoneal injection of the undecapeptide pGlu-Pro-Pro-Glu-Glu-Ser-Lys-Val-Ile-Leu-Phe, a peptide morphogen isolated from the hydra, before hypoxia normalizes lipid peroxidation in the lungs and blood of the five-day-old pups. A compensatory activation of DNA synthesis occurs in tracheal epithelium and hepatocytes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 269–272, March, 1997.     

Effect of the hydra peptide morphogen on cell proliferation in the thymus of newborn rats exposed to prenatal hypoxia

Female rats were exposed to high-altitude hypoxia on days 14–19 of pregnancy. Thirty min before hypoxia the animals were injected with the hydra peptide morphogen in a dose of 10 μg/kg intraperitoneally. Prenatal exposure to hypoxia suppressed proliferative processes in thymic cortex and medulla in newborn rats and decreased the lymphocyte count in the female—newborn rat pairs and the percent of full-term deliveries. Injection of hydra peptide morphogen prevented the development of posthypoxic disorders in newborn rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 9, pp. 348–350, September, 1997     

Effect of hydra undecapeptide morphogen on cell division in the albino rat corneal and lingual epithelium

Central Research Laboratory, Khabarovsk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR D. S. Sarkisov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 10, pp. 425–427, October, 1990.     

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     

Hydra peptide morphogen weakens poststress disturbances in albino rats

The effect of hydra peptide morphogen on poststress disturbances in albino rats is evaluated. A 4-h immobilization leads to a rise of corticosterone, activates lipid peroxidation, impairs antioxidant defense system, and induces a marked decrease in the content of thyrotropic hormone and thyroxine. The relative weight of the thymus significantly decreases 24 h after immobilization. Moreover, stress inhibits proliferative processes in corneal and pyloric epithelium immediately and 24 h after immobilization. Hydra peptide morphogen prevents the endocrine shift, normalizes the content of lipoperoxides and α-tocopherol immediately after stress, weakens poststress proliferation disturbances, induces compensatory stimulation of proliferative processes in the corneal epithelium 24 h after stress, and normalizes DNA synthesis in the pyloric epithelium, the level of malonic dialdehyde being elevated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 10, pp. 392–395, October, 1997     

Effects of hydra peptide morphogen and its analogue and fragments on DNA synthesis in tracheal epithelium and smooth muscle cells in newborn albino rats

Hydra peptide morphogen, its Arg⁷ analogue, and 6C, 3C, and 5N fragments were injected intraperitoneally in a dose 10⁻⁷ mol/kg to newborn rats from the 2nd to 6th day of life. Autoradiography with³H-thymidine showed that hydra peptide morphogen and its 6C fragment stimulated DNA synthesis in tracheal epitheliocytes, but inhibited this process in smooth muscle cells. 5N fragment inhibited DNA synthesis in both tissues, while 3C and Arg⁷ were ineffective. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 6, pp. 646–649, June, 2000     

Effect of hyperbaric oxygenation on some functional and morphological properties of the heart and on catecholamine metabolism in compensatory hypertrophy of the myocardium

Less-marked hypertrophy and signs of myocardial degeneration developed in rabbits exposed for one month to hyperbaric oxygenation (HBO) after the formation of stenosis of the ascending aorta, and the contractile power of the left ventricle was increased more than in animals with stenosis of the aorta kept under ordinary conditions. In rabbits with hypertrophy of the heart developing under conditions of HBO increased powers of adaptation of the myocardium to physical exertion were accompanied by an increase in the functional reserve of the sympathetic control apparatus. HBO evidently favors the development of optimal adaptation of the heart to an increased pressure load.Department of Hyperbaric Oxygenation, All-Union Scientific-Research Institute of Clinical and Experimental Surgery, Moscow. (Presented by Academician B. V. Petrovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 7, pp. 19–22, July, 1977.     

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     

The use of a nonopiate leu-enkephalin analog and of hydra peptide morphogen for the correction of proliferation disturbances in tracheal epithelium and of LPO processes in lungs of newborn rats exposed to prenatal hypoxia

Newborn rats were born of females exposed to high-altitude hypoxia. Pregnant females were injected i.p. either nonopiate leu-enkephalin analog or hydra peptide morphogen 10 μg/kg 30 min prior to being placed in a pressure chamber. Prenatal hypoxia causes the inhibition of the proliferative processes in tracheal epithelium and activation of lipid peroxidation (LPO) in lungs of newborn rats. The administration of nonopiate leu-enkephalin analog prevents the development of posthypoxic alterations in newborn rats. The administration of hydra peptide morphogen inhibits the proliferation of tracheal epithelium and lowers the activity of the antioxidant defense of the lungs in newborn rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 535–537, May, 1994 Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences     

Effect of hypogeomagnetic field on tissue and intracellular reorganization of mouse myocardium

Structural reorganization of the myocardium is observed in CBA mice under conditions of hypogeomagnetic field (reduction by 10⁵ times). Changes in tissue architectonics manifest themselves in a reduced capillary/cardiomyocyte volume ratio against the background of hemodynamic disturbances. Intracellular disturbances result from impaired regeneration processes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 10, pp. 455–459, October, 1997     

Effect of atriopeptides on proliferative processes in albino rat myocardium at the early stage of postnatal ontogenesis

The effect of atriopeptide AP-II and its 6-amino-acid acyclic fragment (7–12) AP-H-6-OH on proliferative processes in the myocardium of 5-day-old albino rats is examined 24 h after a single administration (200 nmol/kg intraperitoneally) by autoradiography with³H-thymidine and by analysis of mitotic regime. A significant decrease in the amount of DNA-synthesizing cells in the right atrium, right ventricle, and interventricular septum is recorded after administration of AP-II. Changes in DNA synthesis are attended by significant changes in the amount of cells in different phases of mitosis, indicating a decrease in the number of mitotic cells and a metaphasal delay. Administration of AP-H-6-OH causes no significant changes in DNA synthesis in the myocardium at the early stage of postnatal ontogenesis. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 9, pp. 321–324, September, 1996     

Distribution of a morphogenic peptide activating the head growth of hydra in rat organs following intravascular administration of3H-labeled peptide

The organ distribution of radioactivity following intravascular bolus injection of³H-Lys-head growth activator in rats was studied. Two minutes after injection the renal level of radioactivity exceeded the blood level 7-fold; 80% of the total activity was bound with the blood cell membranes. An analysis of chemical derivatives of the labeled peptide in the plasma by means of reverse-phase high-performance liquid chromatography revealed the presence of several groups of radioactive metabolites with different hydrophilic properties. High-performance liquid chromatography of blood extracts obtained from samples taken 0.5, 1, 1.5, 2, 31, and 60 min after injection showed the transformation of initially hydrophobic head growth activator into more hydrophilic fragments. The³H-Lys-head growth activator-associated radioactivity could be reliably detected in the blood onl during the first two minutes after injection. The half-period of blood-to-organ distribution of³H-labeled head growth activator lasted less than 30 seconds. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 11, pp. 466–469, November, 1994 Presented by E. I. Chazov, Member of the Russian Academy of Medical Sciences     

Polyploidy in the myocardium and compensatory reserve of the heart

The mammalian heart is a polyploid organ. Cardiac myocytes undergo polyploidization in the early postnatal ontogeny, and the degree of their polyploid depends on the conditions of heart growth. The myocardium of healthy persons is characterized by considerable individual variability of polyploidy. The principal mechanism by which normal and compensatory growth of the heart occurs in adult mammals is through increases of cytoplasmic mass in postmitotic myocytes. In the normal myocardium, the protein mass of myocytes does not correspond to the gene dosage, while their protein mass in a hypertrophic myocardium becomes a multiple of their ploidy. The capacity of polyploid myocytes to grow so as to double their mass constitutes the reserve of cardiac growth. This reserve, which is laid down in the early ontogeny, materializes in response to functional overloading of the heart in adult life. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 5, pp. 454–459, May, 1995 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Effect of δ-sleep-inducing peptide on rat erythrocyte membrane structure in cold stress

δ-Sleep-inducing peptide (1 μg/ml) added to erythrocyte suspension from intact rats enhanced quenching of membrane tryptophanyl fluorescence with pyrene and increased the microviscosity of zones of protein-lipid contacts. Microviscosity and polarity of membrane lipid phase remained unchanged. Exogenous δ-sleep-inducing peptide increased the negative surface charge of the erythrocyte membrane. During cold stress, the efficiency of tryptophane fluorescence quenching with pyrene decreased and microviscosity of protein-lipid contacts decreased, while microviscosity of lipid layer of the erythrocyte membranes did not change; polarity of deep membrane layers and negative surface charge increased. δ-Sleep-inducing peptide normalized the efficiency tryptophane fluorescence quenching with pyrene and membrane microviscosity, polarity, and surface charge. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 9, pp. 317–320, September, 1999     

State of the myocardium in rats of a new hypertensive strain

Study of the heart in a new strain of rats with hereditary stress-induced hypertension (NISAG) reveals a complex of structural and functional changes which are analogous to the manifestations of essential hypertension. These changes are shown to be adaptive-compensatory in nature and indicative of limited functional reserves of the hypertrophic myocardium. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 9, pp. 271–273, September, 1996     

Resistance of the myocardium to adrenalin in rats adapted to hypoxia

The intensity of the changes produced by adrenalin in the myocardium of rats adapted to hypoxia was studied after its administration to the intact animal and perfusion of the isolated heart. The changes were revealed by histochemical reactions for succinate dehydrogenase activity and staining for lipids. After intramuscular injection of a cardiotoxic dose of adrenalin (2.0 mg/kg) into adapted rats no damage to the myocardium was found, whereas perfusion of the isolated heart with adrenalin (20 g/ml) caused the formation of micronecroses of the cardiocytes. However, their volume was statistically significantly smaller than in the isolated heart of intact rats under similar conditions. Differences in the sensitivity of the myocardium in vivo and in vitro indicate that the phenomenon of protection of the myocardium against the harmful effects of adrenalin in rats adapted to hypoxia is manifested at the level of the intact organism. The increase in the resistance of the myocardium itself is probably due to an increase in the power of the metabolic systems during adaptation.Department of Pathological Physiology, Patrice Lumumba Peoples' Friendship University. Department of Geographic Pathology, Research Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 265–268, September, 1977.     

Effect of vagotomy on heart rate in intact and sympathectomized rats of different ages

A comparative analysis of temporal variations of the heart rate variability after cutting and stimulation of the vagus in sympathectomized and intact rats showed that changes in heart rate after bilateral vagotomy in sympathectomized rats are opposite to those in the controls. It is postulated that postganglionic fibers modulate sympathetic influence on intracardiac parasympathetic neurons. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 7, pp. 21–24, July, 1997