Peculiarities of urea distribution in tissues of rats of different age

The content of urea was studied in protein-free filtrates of the liver kidneys, skeletal muscles, myocardium, spleen, brain tissues and blood serum as well as in urine of 1, 3, 6, 12 and 24-month rats. It is shown that at the age of 6 months the content of urine in most tissues under study is significantly decreased (by 42-73%), at the age of 12 months in the spleen and at the age of 24 months in the brain tissues as compared to the one-month animals. The level of urine decrease in the liver and brain tissues of 24-month animals is less pronounced than in other tissues, that corresponds to age peculiarities of their protein metabolism. A decrease of blood consumption per weight unit and a relative increase in the amount of nitrogen excreted with urine are observed with ageing. The arginase activity in the liver decreases essentially only in 3-month animals. A conclusion is drawn that peculiarities of food consumption and the character of changes in the urea content in tissues and urine are adaptation manifestation of an age decrease in the intensity of nitrogen metabolism and protein demand of the organism.     

Ammonia metabolism in tissue of newborn animals in health and in digestive disorders]

Ammonium nitrogen was studied for its metabolism in the tissues of ruminants in transition from pre- to postnatal development in norm and with disorders in gastroenteric digestion. It is established that the intensity of ammonium genesis and glycolysis processes as well as a cycle of tricarbonic acids change in newborn calves as compared to adult animals. The ammonium toxicosis development in sick animals, which is confirmed by an increase of the ammonia level and intensification of the reactions of ammonium- and ureogenesis in tissues of the gastroenteric tract, liver and kidneys.     

Effect of bicarbonates and CO2 concentration increase in tissues on assimilation of ammonium nitrogen in cattle

The feeding of carboxyline and cobalt salts to cattle young fattener receiving the concentrate-silo rations with synthetic nitrogen-containing substances (diammonium phosphate and urea) is accompanied by an increase in the concentration of bicarbonates and CO2 in blood and citric acid in blood plasma with a decrease of the ketonic bodies content in it. The level of carbon dioxide in tissues being increased, the content of ammonium nitrogen in the rumen fluid lowers and the activity of transaminases in blood plasma, the content of glutamate in the liver and that of urea in the rumen fluid increase which evidences for an intensified transformation of the ration nitrogen in the organism. The performance of animals is increased.     

Carbohydrate and nitrogenous metabolism condition in the rat tissue under experimental rhabdomyolysis

Some effects of glycerol injection on indices of the condition of the thiol-disulfide system as well as carbohydrate and nitrogen metabolism in rats in vivo were studied. A decrease was revealed in levels of non-protein SH-groups in the liver, kidney and heart, as well as of protein SH-groups in the kidney and heart of rats following glycerol injection. That might be connected with SH-group oxidation under the excessive arrival of free haem into tissues under rhabdomyolysis. A decrease in glycogen and increase in tyrosine aminotransferase activity in the liver were observed. Activation of nitrogenous metabolism following glycerol injection is indicated by the increase of aminotransferase activity in organs, and concentration of blood urea. High concentration of creatinine in the rat serum can reflect malfiltration in kidneys.     

Effect of arginine and its analogs on the activity of lysosomal and nonlysosomal peptide hydrolases in rat tissues

The autolysis intensity and proteolysis activity at pH 4,5, 7,4, 8,5 and lysosomal and nonlysosomal peptide hydrolase activity have been studied in brain and liver tissues of rats. L-arginine has been found to increase the peptide hydrolase activity in neutral and alkaline media in case of autolysis and proteolysis estimation according to the amino nitrogen increase. When the peptide hydrolase activity is estimated according to the increase of folin-positive components its decrease under the action of arginine in neutral and alkaline media has been revealed. Arginine doesn't change the lysosomal peptide hydrolase activity. In both tissues under the influence of arginine the nonlysosomal peptide hydrolase activity defined by amino nitrogen increases, estimated by the folin-positive components--decreases. Arginine shows the specific influence on the nonlysosomal peptide hydrolase activity. The L-arginine analogues (D-arginine, guanidine) and products of the arginase reaction (ornithine and urea) don't exert such an effect on the nonlysosomal proteolysis.     

Impairment of energy metabolism in rabbit tissues during ammonia toxicosis

The studies are conducted on the model of grave toxicosis in vivo in rabbits. It is shown that an increase in the ammonia content in blood and tissues enhances the content of lactate, glutamate, oxaloacetate in the liver and kidneys of animals, decreases the level of pyruvate, alpha-ketoglutarate and malate in the liver tissue. The NAD+/NADH ratio in the cytoplasm of the liver and kidney cells decreases, the ratio of NADP-pairs in the cytoplasm and mitochondria of these tissues noticeably increases. The energy metabolism is disturbed sharply, the content of adenosine phosphates lowers.     

Creatine biosynthesis enzymes in the postnatal development of rats: the role of cyclo-3',5'-AMP and glucagon in the postnatal induction of liver guanidine acetate-N-methyltransferase]

The activity of enzymes of creatin biosynthesis in the rat liver and kidneys has been studied during the postnatal development. The activity of transamidinase of kidneys (E.C. 2.1.4.1.) increases gradually and linearly up to the 20th day after birth, then decreases on the 12th--25th days and increases again up to the level characteristic of the adult organism. The activity of guanidine acetate-N-methyl transferase (E.C. 2.1.1.2.) is rather high during the first days of postnatal development, then decreases and from the 15th day on increases again attaining the maximal level by the 23rd--25th day. The second period of the increase in the enzyme activity begins on the 29th--30th day of postnatal development. The results obtained suggest that the sharp increase of activity of guanidine acetate-N-methyl transferase of the rat liver during the early postnatal development is realized with the participation of cyclic 3',5'-AMP which appears to mediate the glucagon action.     

Tissue distribution and subcellular localization of retinol-binding protein in normal and vitamin A-deficient rats.

Levels of retinol-binding (RBP), the plasma transport protein for vitamin A, were measured by radioimmunoassay in sera and in a large number of tissues from both normal and vitamin A-deficient rats. The tissues included liver, kidney, fat, muscle, brain, eye, salivary gland, thymus, lung, heart, intestine, spleen, adrenal, testes, thyroid, and red blood cells. The RBP levels in tissues other than serum, liver, and kidneys varied from 12 mug/g of tissue for normal spleen to an undetectable level in red blood cells. Much of the RBP in the tissues with low levels may have been due to residual serum in the samples. In general, except for liver, RBP levels were lower in tissues from vitamin A-deficient rats than in those from normal rats. In normal rats, the liver, kidney, and serum levels were 30 plus or minus 4 (mean plus orminus SEM), 151 plus or minus 22, and 44 plus or minus 3 mug/g, respectively. In vitamin A-deficient rats, the liver RBP level was about three times the normal level whereas the kidney and serum levels were about one-fifth the normal values. When normal liver homogenates were fractionated by centrifugation, 67% of the RBP was recovered in the microsomal fraction and only 9% was found in the soluble 105,000 g supernate. In contrast, 76% of the RBP in homogenates of normal kidneys was in the soluble fraction. Similar results were obtained with deficient livers and kidneys. Incubation with deoxycholate released the liver RBP into the soluble fraction. RBP is produced in the liver and removed from the blood by the kidneys. The levels of RBP in normal and deficient liver, serum, and kidney appear to reflect the relative rates of RBP secretion and turnover.     

Acylase distribution in animal and human tissues

Distribution of acylase in different tissues of nine species of animals was studied. The following types of nitrogen elimination were distinguished: ammoniatelic (fish), uricotelic (birds) and uriotelic (amphibians, mammalians). The enzymic activity was estimated in the tissues of the brain, lung, muscle, liver, kidney, spleen, pancreas, small intestine and blood serum. The acylase activity was found in the kidney, liver and pancreas. Its level in the kidney increases with the animal weight growth, the enzyme activity being observed only in the cortical layer.     

Oxidation and reduction of glutathione in rat organs during the administration of ethonium

An intramuscular administration of ethonium in a dose of 5 and 10 mg/kg 4-6 h later decreases the level of the reduced glutathione and increases that of oxidized glutathione and the glutathione peroxidase activity in the liver and kidneys of albino rats. The duration of the preparation effect depends on the dose and organ, changes in the glutathione reductase activity in the liver, kidneys, lungs, spleen and heart are not found. Participation of ethonium in formation of peroxides in the organism tissues is shown possible.     

Aspartate and alanine aminotransferase activity in the tissues of adrenalectomized rabbits following administration of hydrocortisone and corticotropin

Aspartate and alanine aminotransferase (AsT, AlT) activities were studied in tissues of adrenalectomized rabbits which were treated with a single and multiple administrations of hydrocortisone (5 mg/kg) or a single administration of corticotropine (ACTH, 10 units/kg). It is shown that adrenalectomy decreases the AsT activity in homogenate of femoral muscle tissue and decreases the AlT activity in homogenate and supernatant of the liver, spleen and muscle tissue and in blood plasma. A single administration of hydrocortisone increases the AsT activity in supernatant of femoral muscle tissue and in blood plasma and increases AIT activity in the brain, liver, muscle and blood plasma. Parallel with that AsT and AlT activities are decreased in the spleen tissue. Multiple administration of hydrocortisone induces analogous changes in the AsT activity in the muscle and in the AlT activity in the liver, muscle and blood plasma. A single administration of ACTH induces an increase of the AsT activity in the muscle supernatant and in blood plasma. It also causes a rise of the AlT activity in the liver, muscle supernatant and blood plasma. The AlT activity is decreased in the brain supernatant. A question about stability of free amino acids metabolism (especially of alanine and aspartic acid) in the rabbit brain with changes in corticosteroid levels of organism is under discussion.     

Intensity of metabolism in fish tissues with an increased level of HCO3- and carbon dioxide in their blood

An increase in the HSO3- concentration and in the carbon dioxide level is accompanied by an increase in the glutaminase, alanine and aspartate aminotransferase activities in the liver and kidneys tissues as well as in the blood serum. The in vitro experiments show that an increased level of CO2 in the incubation medium intensifies the incorporation of 14C from I-14C lysine into proteins of the fish liver.     

Effect of pentoxyphylline on certain indicators of the proteinase-proteinase inhibitor system in rats upon administration of cycloheximide

The pentoxifylline influence on neutral proteinase, alpha-2-macroglobulin, trypsin-alpha-1-proteinase inhibitor and elastaseinhibitory activity under cycloheximide injection has been investigated. Two hours after cycloheximide injection the activity of neutral proteinases increases in rats serum, lungs, heart, liver and kidneys. The preliminary injection of pentoxifylline prevents increase of neutral proteinases activity. Cycloheximide also decreases alpha-2-macroglobulin activity in serum and liver and trypsin-, elastaseinhibitory activity of alpha-1-proteinase inhibitor in all investigated organs. At using pentoxifylline the alpha-2-macroglobulin activity doesn't change in liver and increases in serum in comparison with only cycloheximide and there are no observed any alpha-1 inhibitor proteinase activity changes in rats serum and organs.     

Chymase,tonin and elastase in rat tissue under oxidative stress caused by administering cobalt chloride

Character of chymase, tonin and elastase activities changes in rats heart, lungs, liver, kidney under the oxidative stress, induced by cobalt chloride, was investigated. The elastase activity increase in the researched organs and all proteinase indicated in liver were revealed. The specific effect of tonin involvement in injuring effect of cobalt chloride in rat heart is shown, this effect is revealed by local absence of chymase level change, that is determined by its species unsimilarity compare with human. The conclusion about more essential significance of elastase and chymase in injuring effect in lungs and kidneys tissues is made.     

Oxidative damage and antioxidant defense are assay and tissue‐dependent both in captive and wild‐caught bank voles (Myodes glareolus) before and after reproduction

Reproduction is costly and life‐history theory predicts that current parental investment will result in lower survival or decreased future reproduction. The physiological mechanisms mediating the link between reproduction and survival are still under debate and elevated oxidative damage during reproduction has been proposed as a plausible candidate. Previous studies of oxidative stress during reproduction in animals under natural conditions have been restricted to analyses of blood. Herein, we measured the level of oxidative damage to lipids (tiobarbituric‐acid‐reactive substances) and proteins (carbonyls) in the liver, kidneys, heart and skeletal muscles in free‐living bank vole females from spring and autumn generations, before and after reproduction. Antioxidant defense in the liver and kidneys was also determined. We expected oxidative damage to tissues and hypothesized that the damage would be more uniform between tissues in wild animals compared to those breeding under laboratory conditions. Considering all combinations of markers/tissues/generations, oxidative damage in females did not differ before and after reproduction in 12 comparisons, was lower after reproduction in three comparisons, and was higher after breeding in one comparison. The total glutathione was significantly increased after reproduction only in the liver of the autumn generation and there was no change in catalase activity. Our results confirm—for the first time in the field—previous observations from laboratory studies that there is no simple link between oxidative stress and reproduction and that patterns depend on the tissue and marker being studied. Overall, however, our study does not support the hypothesis that the cost of reproduction in bank voles is mediated by oxidative stress in these tissues.     

Functional activity of the thyroid gland and distribution of its hormones in peripheral tissues under experimental liver disease

Experimental acute toxic hepatitis causes functional reconstruction of the thyroid gland accompanied by intensified levels of total iodine and its hormonal compounds in blood. In most of non-thyroid tissues a decrease in the total and hormonal iodine content is revealed, but in kidneys these indices are considerably higher. The level of the nonhormonal iodine compounds in blood and tissues under study does not essentially vary and only in the liver, heart and lungs the expressed lowering of inorganic iodides is observed.     

Features of regulating delta sleep-inducing peptide by free radical processes in tissue and erythrocyte membranes in intact animals and under stress

In activity the comparative analysis of metabolic effects delta--sleep inducing peptide (DSIP) in tissues and erythrocytes of intact rats and under cold stress is conducted. The regulation effect of DSIP in attitude of free radical processes will be realised through modulation the prooxidant--antioxidant balance: both for intact animal, and at stress. Exogenous DSIP increases the antioxidant system activity in tissues of brain, liver and blood in standard conditions and under cold stress. The anti-stress effect of DSIP is directed as on increase of power endogenic enzymatic antioxidant system activity, specially glutathione peroxidase activity, and not enzymatic of antioxidant protection. The DSIP renders different influence on activity of prooxidant enzymes: for intact animal boosts the myeloperoxidase activity in blood neutrophils, not rendering essential influencing on the xanthine oxidase activity in tissues of brain, liver and activates the myeloperoxidase activity, depresses the xanthine oxidase activity for rats at stress. The membranotropic effect of DSIP in the norm and under stress is connected to increase of stability of protein--lipid interplays. The membranostabilizing effect of DSIP in conditions of stress is characterized decrease of polarity of lipid phase and negative surface charge of erythrocyte membranes, modified in course of lipid peroxidation.     

Effect of acute hypoxia on the renin and erythropoietin activities of the blood serum in rats

A comparative study of renin and erythropoietin content in the blood serum of rats with "endocrine" kidneys and changes in their activity following the action of specific erythropoietic stimulus (4-hour hypoxia) has been conducted. The presence of "endocrine" kidneys increased renin and erythropoietin activity in such animals. Acute hypoxia produced further increase in erythropoietin titre in the blood serum, with renin remaining at the same level. Possible differences in the mechanisms of renin and erythropoietin biogenesis in the kidneys are considered.     

State of antioxidant defense and L-arginin-nitrogen oxide system in blood of patients with urogenital chlamydiosis

The system L-arginine-nitrogen oxide plays a significant role in maintenance of the anti-infectious protection of an organism. A condition of the given system and activity of a enzymatic part of antiradical protection in the blood of patients with chlamydiosis has been studied. Obtained data specify an intensification of processes of an oxidizing way of recycling of arginine in an organism of patients. Substantial increase of NO-synthase activity and insignificant activity of arginase in the blood is revealed. The level of nitrite-anion in blood cells of patients authentically increases: 1.7 times in erythrocytes, and 1.4 times in lymphocytes. It is shown, that in patients with chlamydiosis glutathione system is intensified, that is evidenced by an increase glutathione-peroxidase activity and authentic increase of glutathione level. It is assummed that the established features of nitrogen oxide exchange play a significant role in formation of a pathological condition at urogenital chlamydia infections.     

Effect of carbon dioxide dissolved in water on carboanhydrase activity in various organs of carp

The carboanhydrase activity was studied in erythrocytes and tissues of carp gills and kidneys under conditions of exogenic hypercapnia induced by an increase in the level of carbon dioxide solved in the water medium. This enzymic activity in fish erythrocytes is established to be determined by the hypercapnia degree and does not depend on its duration. The carboanhydrase activity in the gills and kidneys is not changed under the effect of higher (within 0,16-1,10 mM) concentration of carbon dioxide for seven days.