Changes in the rate of metabolic clearance of cortisol in dogs after terminal states

In the early period of resuscitation after circulatory arrest for 15 min in dogs the rate of metabolic clearance of 17-hydroxycorticosteroids (17-HCS) was found to be reduced, more especially in animals which subsequently died. This decrease was due mainly to a decrease in the clearance of plasma 17-HCS by organs in the splanchnic region and was evidently connected with the circulatory disturbances.Laboratory of Experimental Physiology of Resuscitation, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 142–143, February, 1977.     

Relationship of changes in the central hemodynamics to the development of posthypoxic cerebral edema in the postresuscitation period

A syndrome of low cardiac output developed between the first and third hours after resuscitation in 16 dogs subjected to circulatory arrest for 15 min. In half of the cases its development was preceded by an increase in the cardiac output in the initial period of resuscitation. Without hyperperfusion at the beginning of resuscitation, the animals died 9–23 h after the beginning of the experiment. Among the surviving animals, edema of the cerebral cortex always developed in dogs with a reduced cardiac output 24 h after resuscitation, but no cerebral edema was observed in dogs with a high cardiac output.Laboratory of Experimental Physiology of Resuscitation, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 266–268, March, 1977.     

Restoration of vital functions of animals revived with a donor circulation after prolonged circulatory arrest

Anesthetized dogs were revived by means of an artificial donor circulation after circulatory arrest lasting 15–20 min. In group 1 the donor's blood was injected toward the heart of the resuscitated dog, whereas in group 2 it was injected toward the heart and brain. In donor-aided resuscitation (especially in group 2) the vital functions were restored more quickly and the number of surviving animals was greater than when other methods of resuscitation were used. Despite the outwardly full recovery of the animals after prolonged circulatory arrest, various degrees of injury took place to their brains, depending both on the duration of clinical death and on the methods of resuscitation.Laboratory of Experimental Physiology of Resuscitation, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 271–273, September, 1977.     

Changes in some hemodynamic,endocrine, and metabolic indices in the early postresuscitation period

Changes in the systemic circulation, the blood flow in the kidney and limb, and certain endocrine and metabolic indices were studied in 24 dogs subjected to circulatory arrest of maximal severity for 17 min in the course of 9 h of the postresuscitation period. Relative compensation and normalization of certain functions and metabolic indices during the first hour after resuscitation were subsequently followed by a new wave of disorders which developed at different times, unequally, and gradually in the body as a whole and in individual peripheral tissues. Disturbances of the peripheral circulation and central hemodynamics were shown to be among the leading pathological manifestations of postresuscitation sickness.Research Laboratory of General Resuscitation, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 87, No. 1, pp. 3–6, January, 1979.     

Hemodynamic analysis of the hypotensive action of portocaval transposition of the vessels in vasorenal hypertension

The effect of portocaval transposition (PCT) on the general hemodynamics was studied in intact dogs and in dogs with experimental vasorenal hypertension. In the experimental dogs the arterial pressure fell after PCT chiefly on account of a decrease in the peripheral vascular resistance to the blood flow. In healthy dogs PCT caused no substantial changes in the hemodynamics.Laboratory of Clinical and Experimental Surgery, Institute of Cytology and Genetics, Academy of Sciences of the USSR, Siberian Branch. Laboratory of Endocrinology, Institute of Clinical and Experimental Medicine, Academy of Medical Sciences of the USSR, Siberian Branch, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 4, pp. 403–405, April, 1976.     

Pathogenesis of the low cardiac output syndrome in postresuscitation states

Acute hypervolemia induced in experiments on dogs by infusion of dextran, did not produce decompensation of the circulation in animals whose cardiac output was sharply depressed in the postresuscitation period after circulatory arrest lasting 15 min. The increase in the venous return and change in the conditions of the peripheral circulation as a result of dextran administration temporarily increased the central venous pressure, caused a lasting increase in the arterial pressure, cardiac output, stroke volume, work of the left ventricle, and total oxygen consumption by the body, and lowered the peripheral vascular resistance. In model experiments on dogs subjected to isolated compression ischemia of the brain for 20 min, a low cardiac output syndrome also developed.Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 7, pp. 787–789, July, 1976.     

Effect of angiotensin II on the hemodynamics after systemic and portal administration

Changes in the general hemodynamics were studied in healthy unanesthetized dogs after injection of angiotensin II for 60 min into the superior vena cava and portal vein at the rate of 27 ng/kg/min. Portal administration of the peptide was found to induce a weaker pressor effect. After systemic injection of angiotensin II the arterial pressure rose as the result of an increase in peripheral vascular resistance, and the minute volume of the circulation was reduced. After portal injection of angiotensin the increase in arterial pressure was due chiefly to an increase in the minute volume of the circulation. The differences in the hemodynamic responses cannot be explained entirely by metabolism of the peptide in the liver. After portal injection of angiotensin II it is possible that depressor substances from the liver enter the blood stream.Laboratory of Clinical and Experimental Surgery, Institute of Cytology and Genetics, Academy of Sciences of the USSR, Siberian Division. Laboratory of Endocrinology, Institute of Clinical and Experimental Medicine, Academy of Medical Sciences of the USSR, Siberian Branch, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 5, pp. 520–522, May, 1976.     

Some aspects of ammonia formation in the brain of dying animals and during recovery after resuscitation

The dynamics of some indices of nitrogen metabolism in the brain was studied in dogs after lethal blood loss and in the postresuscitation period. The investigation showed that the main source of ammonia in the brain during the development of the organism and in the state of clinical death is glutamine. In the recovery period after resuscitation, however, glutamine becomes a remover of ammonia and the main source of ammonia becomes the labile amino groups of proteins.Department of Pathological Physiology, Erevan Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 6, pp. 686–688, June, 1977.     

Acid-base balance of the cerebrospinal fluid in the postresuscitation period

In experiments on dogs whose circulation was stopped for 10 min by electric shock the acid-base balance of the cerebrospinal fluid (CSF) and blood was studied in the postresuscitation period. Although uncompensated systemic acidosis continued for 1 h of the postresuscitation period, acidosis of the CSF was compensated much sooner and was maintained for 6 h at the initial level. Despite the high lactate concentration for 3 h of the postresuscitation period, the bicarbonate concentration during this period remained close to its initial value.Laboratory of Experimental Physiology of Resuscitation, Academy of Medical Sciences of the USSR. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1303–1305, November, 1976.     

Effect of preliminary vibration on the course of ether anesthesia and the postanesthetic period

Experiments on albino rats showed that vibration (46.6 Hz, amplitude 1 mm, duration 3 h) reduces the functional competence of the CNS and also of the respiratory and circulatory systems. Ether anesthesia after vibration aggravates the state of the animals, 60% of which die in the postanesthetic period. Survival of the animals after exposure to extremal factors (vibration, anesthesia) is determined by the level of resistance of the cerebral cortex.Medical Institute, Dnepropetrovsk. (Presented by Academician of the Academy of Medical Sciences of the USSR, A. M. Chernukh.) Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 87, No. 1, pp. 16–19, January, 1979.     

Changes in glycogenolysis in the zone of ischemia in experimental myocardial infarction

During the first minutes after occlusion of the coronary artery in dogs, increased glycogenolysis was detected, for which activation of phosphorylase, phosphofructokinase, triose phosphate isomerase, and lactate dehydrogenase was responsible; aldolase and glyceraldehyde-3-phosphate dehydrogenase reactions became the stages limiting the rate of glycogenolysis. Activation of glycogenolysis was evidently due to the combined action of hypoxia and catecholamines.Laboratory of Pathophysiology of Myocardial Infarction, All-Union Cardiologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR S. E. Severin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 3, pp. 304–307, March, 1980.     

Antibody-forming cells of the rat spleen after injury to the midbrain

The number of plaque-forming cells (PFC) in the spleen of rats immunized with sheep's red blood cells (SRBC) after injury to the anterior or posterior part of the medial hypothalamus and also of the thalamus did not differ significantly from the number of PFC in the spleen of intact animals. The titers of hemolyzing and hemagglutinating antibodies in the animals with injuries to the midbrain were a little lower than in intact rats. The decrease in the quantity of circulating antibodies was not connected with the location of the foci of injury but was evidently a consequence of the craniocerebral trauma.Allergologic Research Laboratory, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. D. Ado.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 2, pp. 185–187, February, 1978.     

Rapid determination of carcinogenic activity of preparations

Correlation was found between erythropoietic activity and resistance of mice both to induced carcinogenesis and to growth of a transplated tumor. By choosing animals with weakened erythropoiesis for the tests the time taken for investigation of carcinogenic activity of preparations can evidently be considerably reduced.Laboratory of Carcinogens, Institute of Nutrition, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meiitsiny, Vol. 80, No. 12, pp. 70–72, December, 1975.     

Effect of period of adaptation on the course of experimental heart failure at high altitudes in the mountains

Data on the state of compensatory hyperfunction of the circulation and respiration in animals with varied degrees of mitral incompetence are given in relation to the periods of adaptation to high-altitude hypoxia in the mountains. In unadapted animals with mitral incompetence more severe disturbances of the hemodynamics and gas exchange were found, accompanied by congestion in the pulmonary and systemic circulatory systems. During the first day after formation of the lesion 52.9% of the animals died. In animals adapted to high-altitude hypoxia the disturbances of the circulation and respiration were milder and only 28.6% of the animals died.Department of Pathological Physiology, Kirghiz Medical Institute, Frunze. (Presented by Academician of the Academy of Medical Sciences of the USSR P. D. Gorizontov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 3, pp. 274–277, March, 1978.     

Comparison of ribonuclease isolated from the liver and pancreas of burned and intact rats

Alkaline RNase was isolated from the pancreas and liver of intact and burned rats and purified 1400 and 2000 times, respectively. The pH-optimum of enzyme activity was 7.6–7.8. Biosynthesis of RNase under normal conditions and after burns was studied by incorporation of labeled amino acids. Inhibition of synthesis of alkaline RNase was found in both organs of the burned animals. The half-life of RNase from the liver of intact rats was 65 min and from the liver of burned animals 100.8 min. Enzymic activity of preparations of alkaline RNase from the liver and pancreas of intact and burned animals did not differ significantly.A. A. Vishnevskii Institute of Surgery, Academy of Medical Sciences of the USSR. Research Institute of Child and Adolescent Physiology, Academy of Pedagogic Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. A. Vishnevskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 305–307, March, 1976.     

Age aspects in the development of vasopressin-induced coronary insufficiency

Electrocardiogram (ECG) changes (enlargement of the T wave, displacement of the S-T segment, disturbances of atrioventricular conduction) arising under the influence of vasopressin in old rats (24–26 months) occur in response to smaller doses of the hormone than in middle-aged (10–12 months) animals. After injection of equal doses the coronary insufficiency was more severe in the older group of animals and was accompanied more often by a disturbance of atrioventricular conduction in the heart of the second to third degree and by distinct disturbances of the hemodynamics.Laboratory of Physiology, Institute of Gerontology, Academy of Medical Sciences of the USSR, Kiev.(Presented by Academician of the Academy of Medical Sciences of the USSR D. F. Chebotarev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 6, pp. 647–650, June, 1976.     

Mitotic activity of lymphocytes in the thymus cortex during hypokinesia and readaptation

Changes in the weight and mitotic index in the thymus cortex of Wistar rats were studied during hypokinesia for 10 days followed by recovery for the same period. The mitotic index was reduced by half, 24 h after immobilization of the animals. During readaptation a stage of secondary stress (when the mitotic index was reduced by 71%) was followed by a stage of true readaptation after 10 days.Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. Institute of Marine Biology, Vladivostok. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 10, pp. 480–482, October, 1979.     

Functional state of the hypothalamo-hypophyseo-adrenal system in guinea pigs exposed to radial acceleration

The effect of an increased gravitational field on activity of the hypothalamo-hypophyseo-adrenal system was studied in experiments on guinea pigs. A single exposure led to activation of this system; however, during repeated exposure to radial acceleration the animals ceased to respond by an increase in the blood corticosteroid level, evidently on account of adaptation of the central components of the system and not of exhaustion of the adrenal cortex.Department of Pharmacology, Institute of Experimental Medicine, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR S. V. Anichkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1313–1314, November, 1976.     

Changes in the systemic hemodynamics produced by vasopressin in dogs during individual development

Indices of the central hemodynamics were studied in puppies aged 18–22 days and 2–3 months and in dogs aged 3–5 years after intravenous injection of synthetic vasopressin (0.8 unit/kg body weight). The pressor effect was strongest in the adult dogs and bradycardia in the puppies aged 18–22 days. The cardiac output was reduced in all animals and the peripheral resistance considerably increased. In adult dogs the external work of the left ventricle and the energy consumption of the heart were increased. In puppies a reduction in the volume velocity of ejection of blood and in the external work of the heart was combined with a smaller increase in energy consumption.Department of Pathological Physiology, Rostov Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR, N. N. Sirotinin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 261–263, March, 1977.     

Histochemical,luminescence, and electron-microscopic study of the pancreas in experimental peritonitis

Various forms of diffuse peritonitis in dogs are accompanied by the development of a secondary inflammatory-destructive process in the parenchyma of the pancreas with the typical vascular and enzyme disturbances, and inflammatory, necrobiotic, and local destructive changes of acute pancreatitis. These changes in the pancreas are evidently an important factor in the mortality from peritonitis.Laboratory of General Pathological Anatomy, Scientific-Research Institute of Human Morphology, Academy of Medical Sciences of the USSR. Group for Electron Microscopy, P. A. Gertsen Moscow Oncologic Scientific-Research Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Strukov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 78, No. 8, pp. 117–120, August, 1974.