Behavioural, biochemical and histochemical effects of locus coeruleus transplantation in rats with neurotoxic lesions of the catecholaminergic system

Exploratory activity in the open field and noradrenaline concentration in the neocortex and brain stem were investigated in intact rats (n = 10) and in the following groups of rats with early postnatal neurotoxic (6-hydroxydopamine) lesion of the catecholaminergic system: (i) rats with embryonal locus coeruleus grafts in the frontal neocortex (n = 5); (ii) rats with the same grafts in lateral ventricles (n = 4); (iii) a control group with intracortical hippocampal tissue grafts (n = 3); (iv) sham-operated rats (n = 3). Experiments were performed by four independent groups of investigators using a double-blind method. In sham-operated rats as well as in rats with hippocampal grafts, and with locus coeruleus grafts in the ventricles, both exploratory activity and noradrenaline content of the forebrain were significantly lowered. In the rats with intracortical locus coeruleus grafts the level of exploratory activity was much higher (almost as in intact controls). This improvement of exploratory behaviour correlated highly with increased noradrenaline concentration in the forebrain. In all animals with locus coeruleus in lateral ventricles a significant increase in noradrenaline level of the brain stem was present, but no change of exploratory behaviour was observed. The grafts with the 3-mm-thick slabs of the adjacent tissue were dissected from the brain and used for histological analysis. The presence of typical locus coeruleus cells was shown in neocortex of all animals which received the grafts of corresponding tissue. The data show the possibility of stable compensation of the forebrain noradrenaline level and exploratory behaviour by embryonic noradrenergic neurons grafted into the neocortex, but not into lateral ventricles.     

Na,K-Atpase in renal tissue of rats in the dynamics of experimental nephritis]

The authors undertook comparative study of the Na, K-ATPase activity in the red cells, ghost corpuscles, and in the cortex and medulla of kidneys of rats with experimental glomerulonephritis (GN) induced by injection of nephrotoxic serum (NTS), during an acute course of the process (1 and 2 weeks after NTS injection) and in chronic affection of the kidneys (10 weeks after NTS injection). The activity of the enzyme both in the red cells and in the ghost corpuscles was reduced significantly, by 28 and 22%, respectively, in the acute period of the disease (one week after NTS injection) but was restored to normal values in the period of chronic affection of the kidneys. The activity of the enzyme did not change in the cortex during the whole period of the study, but in the medulla it diminished in the acute period of the disease and remained reduced (by 27% on the average) during the chronic phase. It is concluded that reduction of the enzyme activity in the studied objects was not caused by the presence of endogenous inhibitors of the enzyme. It is suggested that reduction of Na, K-ATPase activity in the renal medulla may be one of the factors of increase of Na and water excretion in the urine in the chronic phase of GN.     

HPLC/MS Determination of Enalapril and Enalaprilat in the Blood Plasma

A reproducible and sensitive analytical procedure has been developed for the quantitative determination of enalapril and enalaprilat in the blood plasma by high-performance liquid chromatography with mass-spectrometric detection (HPLC/MS). For increasing the sensitivity and reproducibility of analyses, the samples were treated with diazomethane in order to obtain methyl esters of the analyzed compounds. The quantitative determination was carried out using the internal standard method; the internal standard was captopril. The detection was performed in the positive ion mode for ions with m/z = 377 (enalaprilat methyl ester), 391 (enalapril methyl ester), and 267 (captopril methyl ester). Enalapril, enalaprilat, and captopril were isolated from the blood plasma and purified by means of solid-phase extraction. The calibration plot is linear in the concentration range from 0.5 to 200 ng/ml. The detection limits for both enalaprilat and enalapril in the blood plasma are 0.1 ng/ml.__________Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 2, pp. 49 – 52, February, 2005.     

Features of the formation, expression and transmission of basic genetic and androgen programs of the level of unusual estrogen-binding protein in sexually mature female rat hepatocytes under experimental conditions]

Some features of the formation, expression and inheritance of basic genetic and androgen programs of the level of unusual estrogen-binding protein (UEBP) in mature female rat hepatocytes under experimental conditions were investigated. Liver regeneration after partial (2/3) hepatectomy of mature rats was used for generation of a new population of differentiated hepatocytes. The UEBP content was determined by radioligand technique in control liver and at 2, 4, 14 days of liver regeneration and related to the total DNA content as an indicator of cell proliferative activity. It was revealed that the basic genetic program of low UEBP level of hepatocytes of ovariectomized females was fully transferred to daughter cell during cell proliferation and characterized by a temporary elevation of its expression during initial steps of liver regeneration. It was shown that the androgen program of a high UEBP level was completely and stably formed after androgen action in hepatocytes of ovariectomized females and was fully transferred to daughter cells during hepatocyte proliferation. However experimentally formed androgen program of a high UEBP level in female hepatocytes was completely revealed only during early steps of liver regeneration (the 4th day), its expression was essentially declined after regeneration process was over.     

Lipid peroxidation and the mechanisms of hepatocyte damage and protection in chronic hepatitis and cirrhosis

A study was made of the indices of lipid peroxidation (LPO)--conjugated dienes (CD) and diene ketones (D), cyclic nucleotides (CN)--cAMP and cGMP, prostaglandins (PG) E and F2 alpha in biopsy tissue of the liver in 55 patients with chronic hepatitis (CH) and liver cirrhosis (LC). LPO was determined by spectrophotometry, CH and LC--by a radioimmunoassay. In patients with CPH and CAH the indices of LPO and cGMP were normal, cAMP, PG and PGE/PGF2 alpha were raised. In a severe fast progressive liver lesion disorder of coordination activity of the cell membranous systems was characterized by a high LPO activity, a decrease in cAMP and relative deficit of liver PG.     

Stability and variability in hormonal responses to prolonged exercise.

To study the dynamics of alterations in blood hormones and their individual variability during prolonged exercise, changes in plasma levels of corticotropin, cortisol, aldosterone, testosterone, progesterone, somatotropin, insulin and C-peptide were recorded in 32 endurance athletes and 50 untrained persons during a 2-hour exercise on a cycle ergometer at 60% VO2max. Common changes were activation of the pituitary corticotropin function, mostly at the end of exercise, rises in aldosterone and somatotropin concentrations and decreases in insulin and C-peptide levels during exercise. The activation of pituitary-adrenocortical system and the decrease of insulin but not C-peptide levels were more pronounced in athletes than in untrained persons. A large inter-individual variability existed in changes of cortisol, testosterone and progesterone in both groups. Five variants were found in the dynamics of cortisol concentration. Whereas the alterations of corticotropin were characterized mainly by a biphasic increase, the dynamics of corticotropin and cortisol coincided only in one variant out of five. Most characteristic for the postexercise recovery period were decreased activity of the pituitary-adrenocortical system and delayed normalization of aldosterone level.     

Effect of platinum-containing cytostatics on rat progeny

Pathological changes in internal organs are seen in some offspring of intact females and males treated with platidiam 1 month before mating. One case of malformation was found in the progeny of cytostatic-treated females. High embryonal mortality is noted in animals treated with cytostatics 3 and 6 months before mating. Delayed ossification is observed in some animals of almost all experiments groups. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 11, pp. 516–519, November, 1997     

Effect of verapamil on development of the pain syndrome in rats after sciatic nerve division

Laboratory of Pathophysiology of Pain and Laboratory of General Pathology of the Microcirculation, Research Institute of General Pathology and Pathological Physiology, Russian Academy of Medical Sciences, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 114, No. 9, pp. 229–231, September, 1992.