Effect of the normal microflora and age and sex of rats on the serum IgG2 level

Germfree and ordinary rats, bred in the laboratory, and rats obtained from nurseries were used. IgG₂ was isolated from the serum of noninbred rats and a rabbit antiserum against it obtained. By radial immunodiffusion the quantity of this immunoglobulin was determined in the blood serum of different groups of animals. The IgG₂ content in germfree rats of the Fisher strain was only 19% of that in animals of this strain obtained from the nursery, and in females it was 10–15% higher than in males. The IgG₂ level in newborn rats within a few hours after birth was identical regardless of its concentration in the maternal blood serum. The results may be used as standards for various immunological experiments on rats.Laboratory of Gnotobiology, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 9, pp. 335–337, September, 1978.     

Effect of antihepatocytotoxic serum on cellular and intracellular regeneration of the pathologically changed liver

Parameters of regeneration of the liver (mitotic index, DNA synthesis, volume of hepatocyte nuclei, and histological structure) were studied in experiments on adult male rats with liver damage induced by CCl₄ and receiving injections of antihepatocytotoxic serum (-AHCS) during regeneration of the liver after CCl₄ poisoning; cellular and intracellular forms were found to predominate at different times. -AHCS given in a dose of 0.06 g protein/100 g body weight per injection stimulates and prolongs regeneration of the liver at both cellular and intracellular levels.Department of Immunology and Cytotoxic Sera, A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, 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. 89, No. 3, pp 368–370, March, 1980.     

Effect of estrogens on the blood serum level of carcino-embryonic antigen in rats with neoplasms of the intestine and nonspecific injuries of its mucosa

Carcino-embryonic antigen (CEA) was detected in the blood serum of 70% of rats with tumors of the large intestine induced by 1,2-dimethylhydrazine and with posttraumatic regeneration of the mucosa of the large intestine. After injection of estrogen (diethylstilbestrol proionate, 0.57 g daily for 6 days) the frequency of appearance of CEA in such animals increased, as also did the CEA level in the blood serum. In rats with injury to the mucosa of the large intestine, injection of estrogen prevented the natural decrease in the CEA concentration as the intensity of the regenerative process diminished.Laboratories of Experimental Tumors and Endocrinology, N. N. Petrov Scientific-Research Institute of Oncology, Ministry of Health of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR V. I. Ioffe.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 5, pp. 582–583, May, 1977.     

Changes in the level of epidermal G2 chalone and mitotic activity in the vaginal epithelium of rats

The content of epidermal inhibitor of mitosis (G₂ chalone) at different stages of the estrous cycle in rats was determined by the radial immunodiffusion method. The chalone level correlates with the mitotic index of the vaginal mucous membrane and is minimal in proestrus and maximal in estrus. In aging (14–16 months) rats with regular cycles the content of G₂ chalone in the vaginal mucous membrane at all phases of the estrous cycle was significantly lower than in young (3–4 months) rats with a regular cycle. In castrated rats the mitotic index begins to rise 18 h after a single injection of estradiol benzoate (1 g/100 g body weight). This increase is preceded by a significant decrease in the concentration of G₂ chalone 12 h after injection of the estrogen.Laboratory of Experimental Tumors and Laboratory of Endocrinology, N. N. Petrov Research Institute of Oncology, Ministry of Health of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Serebrov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 4 pp. 349–351, April, 1979.     

Sexual dimorphism in the contribution of protein kinase C isoforms to nociception in the streptozotocin diabetic rat

The contribution of second messenger signaling, glucose level and sex hormones to sexual dimorphism in the streptozotocin model of diabetic painful peripheral neuropathy was evaluated. Streptozotocin induced elevation of blood glucose and mechanical hyperalgesia (measured by the Randall-Selitto paw-withdrawal test) were both greater in female rats. Ovariectomy abolished and estrogen implants reconstituted this sexual dimorphism; gonadectomy in males had no effect. An inhibitor of protein kinase Cε attenuated hyperalgesia in males and ovariectomized females, but not in normal females or in ovariectomized females with estrogen implants, whereas inhibitors of protein kinase Cδ attenuated hyperalgesia in females but not in males. Inhibitors of protein kinase A, protein kinase C (non-selective), protein kinase G and nitric oxide synthase attenuated hyperalgesia equally in both sexes. Higher blood glucose levels in diabetic females were also sex hormone dependent, and magnitude of hyperalgesia correlated with blood glucose level in diabetic male and female rats. These results demonstrate sexual dimorphism in diabetic hyperalgesia, mediated by sex hormone dependent differences in protein kinase Cε and protein kinase Cδ signaling and blood glucose levels and suggest that sex may be an important factor to be considered in the treatment of symptomatic diabetic neuropathy.     

The effect of glutathione,vitamins B12 and B1. and rutin on the level of cholesterol in the brain,liver and blood in alimentary hypercholesterinemia

Summary The paper deals with materials on the effect of glutathione, vitamins B₁₂ and B₁, rutin and a combination of glutathione with vitamin B₁ or rutin on the cholesterol level in the blood, liver and brain during alimentary hypercholesterinemia. Experiments were staged on 266 chicks.Hypercholesterinemia was provoked by cholesterol-containing diet given for a period of 18 days. After the cessation of cholesterol administration, the chicks were given vitamin B₁₂ in a dose of 0.1 and 2, 0.2 mg of vitamin B₁ subcutaneously, rutin with food –100 mg per kg of body weight, glutathione –12.5 mg per 100 g of weight and combinations of glutathione with rutin or with vitamin B₁ in the aforesaid doses for a period of 10, 15, and 20 days. The chicks were decapitated after suspension of this treatment. Cholesterol concentration was determined in the blood, liver and brain. As established, cholesterol feeding markedly increased its content in the blood and liver. After discontinuance of cholesterol administration its content in the blood and liver drops almost to the initial level in 20 days. The hypocholesterizing effect of vitamin B₁₂ given in a dose of 0.1, of glutathione-rutin combination and of rutin alone was established. These were no changes in the cholesterol content of the brain tissue.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten Ékjsperimental'noi Biologii i Meditsiny, Vol. 51, No. 2, pp. 46–48, February, 1961     

Role of overloading of the vacular apparatus in changes in liver cell lysosomes in acute toxic hepatitis

The physicochemical properties of the liver lysosomes were investigated in rats after administration of a single dose of the lysosomotropic agent Triton WR 1339 to intact rats and to rats with acute toxic hapatitis. Administration of the detergent to intact animals was followed by a decrease in the buoyant density of the particles, solubilization of the lysosomal enzymes, and reduced resistance of the particles in a hypotonic medium. Signs of overloading of the vacuolar apparatus with the detergent also were found in the liver cell lysosomes of rats with toxic hepatitis. The most marked solubilization of -galactosidase, acid RNase, and cathepsin D was observed in the case of combined administration of CCl₄ followed by WR 1339 24, 48, and 72 h and 7 days later. The possible consequences of overloading of the vacuolar apparatus of the rat liver cells are discussed.Central Research Laboratory, Novosibirsk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 3, pp. 234–237, March, 1979.     

Blood serum and liver phospholipids of rats with chronic choline—protein deficiency

The phospholipid content in the blood serum and liver tissue was studied for a period of eight months in rats kept on a cirrhosis-inducing diet with a high fat content and deficient in protein and choline, in animals receiving the same diet but with the addition of choline, and in control rats. Depending on the duration of its administration, the cirrhosis-inducing diet led to fatty infiltration of the liver, fibrocysts, and cirrhosis. At all stages of the pathological process there was a marked decrease in the phospholipid content in the blood serum and liver. In rats with developed nodular cirrhosis a tendency was observed for the phospholipid level to rise, possible on account of newly formed liver tissue. Choline prevented the development of fatty infiltration but did not completely prevent the fall in the phospholipid concentration in the liver.Presented by Academician of the Academy of Medical Sciences of the USSR E. M. Tareev.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 79, No. 6, pp. 47–49, June, 1975.     

Age increase in the threshold of sensitivity of the tonic region of the hypothalamic sex center to inhibition by estradiol in female rats

To study the sensitivity of the hypothalamic sex center to the inhibitory action of estrogens, estradiol-17 was injected into the third ventricle of hemicastrated rats. The dose of estrogen needed to inhibit compensatory hypertrophy of the ovary by 50 and 100% in old animals (14–16 months) was 4 to 5 times greater than in young rats (3 months). The results point to an age increase in the threshold of sensitivity of the tonic region of the hypothalamic sex center to inhibition by estrogens and they can be used to explain the mechanisms of the age increase in gonadotropin secretion and the termination of reproductive function.Aging Mechanisms Group, Laboratory of Endocrinology, Professor N. N. Petrov Research Institute of Oncology, Ministry of Health of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR N. P. Bekhtereva.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 8, pp. 228–230, August, 1978.     

Neuroendocrine control of the gonadotropic function of the hypophysis in experimental diabetes

Conclusions  

Effect of ionizing radiation on the uric acid and allantoin contents of the blood and urine of animals

Summary The uric acid and allantoin contents of the blood and urine of dogs and rats receiving lethal doses of -and -radiation have been determined. The uric acid contents of the blood and urine fell by 15–45% during the course of radiation sickness, while the allantoin contents rose by 30–50%. The food rations of the control animals were restricted to those of the irradiated ones, and were quantitatively inadequate; the uric acid content of the blood and urine rose under these conditions by 17–20%, and the allantoin content by 12–15%.Experiments on rats with a circulatory by-pass of the liver showed that at the height of radiation sickness the liver removed more uric acid from the blood than normally, but put out more allantoin.Presented by Active Member AMN SSSR A. E. Braunshtein     

Effect of antihepatocytotoxic serum on DNA synthesis in the rat

Incorporation of thymidine-³H into parenchymatous and reticulo-endothelial cells of the liver was studied autoradiographically in adult female rats treated with small doses (0.06 g/100 g body weight per injection) of antihepatocytotoxic serum (AHTS), the -globulin isolated from it (AHTS), and the -globulin fraction of normal rabbit serum (NRS) to intact animals and to rats with liver damage caused by carbon tetrachloride (CCl₄). Following injection of AHTS and, to a lesser degree, of AHTS into intact animals the index of labeled nuclei of both the parenchymatous and the reticulo-endothelial cells was increased. When given after preliminary CCl₄ administration, AHTS stimulated reparative regeneration. The action of AHTS took place in phases: A period of increase in the index of labeled nuclei was followed by a period of decrease, and this again was followed by a fresh period of stimulation of proliferative processes.Department of Immunology and Cytotoxic Sera, A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, 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. 86, No. 7, pp. 75–78, July, 1978.     

A multicomponent system of estradiol-binding proteins in rat liver cytosol and its dependence on sex steroids

The marked sex differences in the ratio between the hormonal capacity of estradiol-binding components with Stokes' radii (a) of 7.0 and 2.5 nm observed in sexually mature animals are somewhat reduced but do not disappear completely after gonadectomy. Prolonged administration of estradiol (50 g, 8days) to gonadectomized rats leads to depression of the estradiol-binding activity of all components of liver cytosol of females and males. Injection of testosterone propionate (2 mg, 8 days) into gonadectomized animals leads to selective stimulation of a special estrogen-binding protein with a=2.5 nm, normally characteristic of males alone, in both males and females. It is postulated that sex differences in the system of estradiol-binding proteins of the rat liver cytosol are due to sexual differentiation of the system in the early stages of development, on the one hand, and to the active regulatory influence of androgens and estrogens in the late stages of development, on the other hand.Laboratory of Endocrinology, Biological Faculty, M. V. Lomonosov Moscow State University. (Presented by Academician of the Academy of Medical Sciences of the USSR S. E. Severin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 5, pp. 548–551, May, 1977.     

Metabolic alterations induced by chronic heat exposure in the rat: the involvement of thyroid function

The effects of chronic exposure to high environmental temperature (34°C) on T₄ production rate, foodintake, growth-rate and resting metabolic rate were investigated in adult male rats. This study was designed to examine the extent of variations and possible relationships between these parameters. As compared to control rats of the same body weight kept at 25°C, rats exposed to 34°C for 3–4 weeks exhibited a retarded growth-rate: 2.3 vs 4.0 g/day, a reduced food-intake: 15.2 vs 23.2 g/day, a decreased T₄ production-rate: 1.8 vs 2.7 g/day and a decreased oxygen consumption: 4.0 vs 5.4 ml/min. Heat-exposure altered the 4 parameters to a similar extent. T₄ supplementation (3 g/day) which induced a decrease in plasma TSH concentration, did not restore a normal growth-rate in heat-exposed rats. The decreased food-intake of the heat-exposed rats was not associated with any significant changes in the daily pattern of variations of liver glycogen content, or in the mean daily levels of blood glucose or insulin. The ratio T₃ to rT₃ in plasma was not altered by chronic heat exposure. When rats which had been chronically exposed to heat (25 days at 34°C) were exposed to 25°C, growth-rate, food-intake and oxygen consumption rapidly increased to control values whereas the rate of T₄ production remained low. It is concluded that (1) a decrease in thyroid hormone economy is not directly involved in the alterations of growth and energy expenditure in rats chronically exposed to heat, (2) heat exposure does not lead to the establishment of a fasted state resulting from a large reduction in voluntary food intake, (3) metabolic alterations induced by heat exposure are rapidly and completely reversible upon decreasing the environmental temperature.     

Distribution of γ-hydroxybutyric acid in different parts of the brain and blood serum during development of anesthesia in rats

The dynamics of accumulation of -hydroxybutyric acid (GHBA) in various parts of the brain (thalamus, hypothalamus, cerebellum, corpus striatum, cerebral hemispheres, medulla, corpora quadrigemina) and in the blood serum of rats was studied by an improved gas-chromatographic method after intraperitoneal injection of sodium -hydroxybutyrate (1.5 g/kg). The GHBA concentration in all parts of the brain studied during induction and development of anesthesia and recovery of the animals from it was practically identical, although at all stages of anesthesia a higher level of the compound was found in the cerebral hemispheres, cerebellum, and corpus striatum. The GHBA concentration in the blood serum was constantly higher (especially in the initial period) than in the brain tissues.Belorussian Health and Hygiene Research Institute, Minsk. Minsk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 434–436, October, 1977     

The impact of joint angle and movement velocity on sex differences in the functional hamstring/quadriceps ratio

Background

Females are two to eight times more likely to suffer a non-contact injury compared with males thus the purpose of this study was to explore the influence of joint angle and movement velocity on sex differences in the functional hamstring to quadriceps ratio (H/Q_FUNC).

Brain Blood Flow Modulates the Neurotoxic Action of Hyperbaric Oxygen via Neuronal and Endothelial Nitric Oxide

Studies on conscious rats with inhibition of NO synthase were used to assess the dynamics of brain blood flow and EEG traces during hyperbaric oxygenation at 4 or 5 atm. Oxygen at a pressure of 4 atm induced cerebral vasoconstriction in intact animals and decreased blood flow by 11–18% (p < 0.05) during 60-min exposure to hyperbaric oxygenation. Paroxysmal EEG activity and oxygen convulsions did not occur in rats at 4 atm of O₂. At 5 atm, convulsive activity appeared on the EEG at 41 ± 1.9 min, and blood flow decreased significantly during the first 20 min; blood flow increased by 23 ± 9%, as compared with controls, (p < 0.01) before the appearance of convulsions on the EEG. Prior inhibition of NO synthase I (NOS I) and NO synthase III (NOS III) with N-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg) or inhibition only of NOS I with 7-nitroindazole (7-NI, 50 mg/kg) prevented the development of hyperoxic hyperemia and paroxysmal spikes on the EEG during hyperbaric oxygenation at 5 atm. These results show that hyperbaric oxygen induces changes in cerebral blood flow which modulate its neurotoxic action via nitric oxide synthesized both in neurons and in cerebral vessels.     

Comparative immunochemical analysis of specific β-globulins of the “pregnancy zone” in humans and other mammals

It was shown by immunodiffusion analysis that the specific ₁-globulin of human pregnancy and the analogous -globulins of other mammals (rats, guinea pigs) possess an individual antigenic structure. Animals of closely related species (rats and mice) were shown to have immunologically similar -globulins, which are evidently synthesized in the placenta, in their blood serum during pregnancy.Department of Biochemistry and Labotatory for Problems in Immunochemistry of Malignant and Embryonic Tissues, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. M. Lopukhin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 10, pp. 1223–1225, October, 1976.     

Pattern of hyperlipidemia in rats with chronic renal failure

The character of the hyperlipidemia was studied in rats with chronic uremia caused by removal of five-sixths of the total weight of kidney tissue. The blood cholesterol and phospholipid concentrations were almost twice the normal level 13–30 days after subtotal nephrectomy in the rats with uremia. The hyperlipidemia was more marked when the blood nonprotein nitrogen level was high. The serum triglyceride concentration was not increased. The total concentration of serum -and pre--lipoproteins, determined nephelometrically, was significantly increased only if the nonprotein nitrogen exceeded 80 mg%. Disk electrophoresis of the serum lipoproteins of the rats with uremia revealed a definite increase in the -lipoprotein concentration and a very small increase in the -lipoprotein concentration. Postheparin plasma lipolytic activity in the rats with uremia was normal. Massive proteinuria was observed in the experimental rats, but the hypoproteinemia was not significant.Nephrology Problem Laboratory, I. M. Sechenov First Moscow Medical Institute. Pathomorphological Laboratory, Institute of Nutrition, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR E. M. Tareev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 6, pp. 676–679, June, 1978.     

Properties and kinetics of the B lymphocyte population of rats during development

Cells carrying surface immunoglobulins (Ig⁺ cells) detected by the indirect immunofluorescence method, and cells forming rosettes with sheep's red blood cells (SRBC) with antibodies adsorbed on their surface and with complement (RFC), were found in the liver and spleen of rat fetuses at the 15th and 20th days of development. The relative percentage of Ig⁺ cells and RFC in the liver remained low and about the same level in rats on different days of postnatal development. In the spleen and bone marrow the number of Ig⁺ lymphocytes and RFC increased during the first month of the rat's life, to reach a maximum in animals aged 30 days, and fell sharply in old rats. No Ig⁺ cells or RFC were present in the thymus or they were found in very small numbers at certain times of investigation. Ig⁺ lymphocytes with caps of fluorescence on their surface appeared in the spleen and bone marrow on the fifth and 10th days of life of the rat and their number rose considerably by the age of 30 days and in adult rats. No such cells were present in the lymphoid organs of old (40 months) animals.Laboratory of Embryonic Histogenesis, Institute of Human Morphology, Academy of Medical Sciences of the USSR. Institute of Molecular Biology, Academy of 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. 10, pp. 491–494, October, 1977.