Pharmacokinetics of lithium in rats of various ages

The kinetics of lithium in serum was determined in rats aged 5 to 240 days, after 2 days of pretreatment with 0.15 mval Li+/100 g and a load of 0.3 mval Li+/100 g body weight at the day of experiments. In rats age differences in distribution and elimination of lithium can be described by a two-compartment model. The kinetic parameters were calculated (half-life(serum), apparent volume of distribution, rate constants of distribution and elimination, total plasma clearance) and, additionally, age differences in renal elimination were determined (renal clearance, half-life (urine)). The ability to excrete lithium is not fully developed in 5-day-old rats: t1/2serum (23 h) and especially t1/2urine (72 h) are much longer than in adult rats (t1/2serum = 12 h; t1/2urine = 6.4 h). The influence of administered lithium on the regulation of the electrolyte balance in the organism (sodium, potassium) occurred differently in dependence on age. Consequences of the investigations are discussed for the therapy with lithium in different age periods.     

青春双歧杆菌对2型糖尿病模型大鼠免疫功能和肾脏的影响

目的通过观察青春双歧杆菌对2型糖尿病模型大鼠血清中细胞因子IL-2、IL-6和IFN-γ活性的影响,以及血清及尿中的NO与ET-1的变化,探讨青春双歧杆菌对2型糖尿病模型免疫功能和肾脏的影响。方法采用青春双歧杆菌灌胃2型糖尿病模型大鼠,取血液和尿液,ELISA法检测细胞因子IL-2、IL-4、IL-6、IFN-γ和ET-1活性,硝酸酶还原法测定NO水平。结果青春双歧杆菌提高IL-2、IL-4水平,降低IL-6、IFN-γ和ET-1活性,NO水平在病程中动态变化。结论青春双歧杆菌具有平衡2型糖尿病模型大鼠免疫功能,抑制ET-1,调节NO水平的作用,从而预防肾小球硬化的发生。     

Mutagenic effect of the rocket fuel component asymmetric dimethylhydrazine on rats of various ages

Mutagenic effect of asymmetric dimethylhydrazine (ADMH) on rats of different age groups upon acute and subacute treatment and protective effect of a Limonium gmelinii preparation. Genotoxic effect of ADMH depending on the dose and duration of treatment was established. The phytopreparation lacked mutagenicity and toxicity and had a protective effect in combination with the xenobiotic.     

Aminotransferase activity in the brain of rats of various ages during hypothermia

Studies have been made on the activity of aspartate and alanine aminotransferase in the brain of 1, 4, 12-14, 16, 22 days, 1, 1 1/2, 3 months and 2 years old rats under hypothermic conditions (20-19 degrees C). It was shown that hypothermia decreases both total and specific activities of the enzymes in the developing brain. Alanine aminotransferase activity in brain homogenates determined at 37 and 20-19 degrees C, exhibits more significant changes than of aspartate aminotransferase.     

Influence of steroid-hormone-receptor-protein complexes on initiation of ribonucleic acid synthesis in liver nuclei isolated from rats of various ages.

The effect of age on the induction of the initiation of RNA synthesis was investigated in liver nuclei isolated from adrenalectomized rats of various ages after binding of a dexamethasone-receptor-protein complex. Binding of this complex to nuclear chromatin resulted in increased initiation of nuclear RNA synthesis at all ages; however, an age-associated decline in the extent of this induction was observed. This suggests an age-related decrease of total rat liver nuclear RNA synthesis with a decreased response to glucocorticoid hormones.     

Lipid hydroperoxide levels in the heart and liver of rats of various ages

The level of lipid hydroperoxides and secondary products of peroxide oxidation of lipids reacting with 2-thiobarbituric acid (TBA) has been studied in the heart and liver of Wistar male rats aged 1, 3, 12 and 24 months. It is shown that the both indices in the heart lower in the pubertal period of ontogenesis and do not vary with the further ageing. The content of hydroperoxides in the liver is unchanged and that of secondary TBA-active products decreases with the age.     

Special feature for the Olympics: effects of exercise on the immune system: neuropeptides and their interaction with exercise and immune function

It is known today that the immune system is influenced by various types of psychological and physiological stressors, including physical activity. It is well known that physical activity can influence neuropeptide levels both in the central nervous system as well as in peripheral blood. The reported changes of immune function in response to exercise have been suggested to be partly regulated by the activation of different neuropeptides and the identification of receptors for neuropeptides and steroid hormones on cells of the immune system has created a new dimension in this endocrine-immune interaction. It has also been shown that immune cells are capable of producing neuropeptides, creating a bidirectional link between the nervous and immune systems. The most common neuropeptides mentioned in this context are the endogenous opioids. The activation of endogenous opioid peptides in response to physical exercise is well known in the literature, as well as the immunomodulation mediated by opioid peptides. The role of endogenous opioids in the exercise-induced modulation of immune function is less clear. The present paper will also discuss the role of other neuroendocrine factors, such as substance P, neuropeptide Y and vasoactive intestinal peptide, and pituitary hormones, including growth hormone, prolactin and adrenocorticotrophin, in exercise and their possible effects on immune function.     

Influence of physical exercise on human preferences for various taste solutions

The effects of physical exercise on preference for various sapid solutions was studied in 58 healthy university students. After 30 min of exercise using a bicycle ergometer at 50% VO2max (maximal oxygen uptake) intensity, a rating scale test on taste hedonic tone and the triangle test for taste absolute threshold were done. The test solutions were sucrose, NaCl, citric acid, caffeine and monosodium glutamate (MSG). Preference scale values for sucrose and citric acid increased after exercise, whereas the values for NaCl, caffeine and MSG were not changed. The absolute thresholds for all the sapid solutions did not differ for pre- and post-exercise. These findings indicate that in humans preference for sucrose and citric acid increase after physical exercise.      

Effect of caloric restricted diet on the liver microsomal monooxygenase system in rats of various ages

Dietary restriction is the only known experimental method to extend lifespan in mammals, but the mechanisms of this phenomenon are still unknown. It is determined that the keeping of animals on the calorie restricted diet results in essential changes of a drug-metabolizing enzymes contents, that is also confirmed by the change of response of the enzyme system to thyroxine action. As a whole, the results obtained will be coordinated with the point of view, according to which the action mechanisms of the dietary restriction consist in considerable change of a wide spectrum of biochemical processes, including the change of the level of monooxygenase system functioning.     

Frequency of chromosome aberration in liver cells of rats of various ages

Frequency of chromosome aberrations in the liver cells of hepatectomized Wistar rats aged 3, 9, 12 and 18 months was studied. Changes in the number of chromosomes and damage of their structure at the metaphase stage of the first division hepatocytes are analyzed. The content of aneuploid cells was 1-3% of the total number of metaphases studied and did not change with the age of animals. Frequency of chromosomal aberrations increased with aging from 1.3 to 6.9 in rats aged 3 and 18 months, respectively, mainly due to chromatid-type aberrations.