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49 záznamů v PubMed Filtry

Článek

Disappearance of radioactivity from perfusate of isolated rat liver after administration of different doses of tritiated DH-ergotoxine

Sbornik vedeckych praci Lekarske fakulty Karlovy university v Hradci Kralove. 1991 ; 34 (3) : 249-54.

Sb Ved Pr Lek Fak Karlovy Univerzity Hradci Kralove
ISSN 0049-5514
Zdroj

In ergot alkaloids a disproportion between the size of the peroral dose and the achieved area under the curve concentrations was described. This process can be explained by nonlinearity in the absorption, distribution or elimination of alkaloids. The aim of the present paper is to find whether elimination of tritiated DH-ergotoxine (3HDHE) in the liver is a linear, dose-independent process. Therefore on the model of the isolated rat liver disappearance of radioactivity in perfusate after the administration of two doses of 3HDHE, viz. 60 ng g-1 of the liver and 3030 ng g-1 of the liver, was investigated. The disappearance curves of radioactivity expressed as the percentage of the administered dose did not significantly differ between both groups. No significant changes between the groups were found either in the size of pharmacokinetic parameters, or in the portion of the administered radioactivity excreted in bile. Therefore the present authors think that disappearance of radioactivity in perfusate of the isolated liver after administration of 3HDHE is a linear process following first-order kinetics.

Článek

Kinetics of 3H-thymidine label in rat liver regenerating after partial hepatectomy and after damage with carbon tetrachloride or silica

Sbornik vedeckych praci Lekarske fakulty Karlovy university v Hradci Kralove. 1989 ; 32 (4) : 395-401.

Sb Ved Pr Lek Fak Karlovy Univerzity Hradci Kralove
ISSN 0049-5514
Zdroj

Rat liver DNA was labelled with [methyl-3H] thymidine after partial hepatectomy, carbon tetrachloride poisoning, or an intravenous injection of silica dust. Changes in DNA labelling were studied for 4 weeks after the single pulse. Total radioactivity incorporated into liver DNA after partial hepatectomy and after carbon tetrachloride administration remained on the same level when compared with that found after 1 h. DNA activity in liver of untreated rats and of rats treated with silica decreased by about 50% within the first 2 weeks and then remained on this level for the rest of the studied period. These differences may reflect the fact that hepatocytes that have a long life span are preferentially labelled in partially hepatectomized and CCl4-treated rats, while liver macrophages with a short half-life take up a large part of the label in intact rats and in rats treated with silica.

Článek

Hormonal and organ weight changes in rats exposed to simultaneous chronic effects of CO and NO2

Journal of hygiene, epidemiology, microbiology, and immunology. 1988 ; 32 (3) : 279-85.

J Hyg Epidemiol Microbiol Immunol
ISSN 0022-1732
Zdroj

UNLABELLED: Activity of the pituitary-adrenocortical, sympathico-adrenomedullary and thyroid gland systems was examined in groups of male adult rats, average weight 180 g, exposed for 2 months to a mixture of 7 mg.m-3 NO2 and 32 mg.m-3 CO in air and in groups of matched controls inhaling fresh air. Corticosterone (B) concentrations in the serum of rats were determined by the competitive protein-binding method, noradrenaline (NA) in the hypothalamus and catecholamines (CA) in suprarenals by fluorometry, thyroxine (T4) and triiodothyronine (T3) in the thyroid gland by the RIA technique. Measurements of organ weight were related to overall body weight. The data emerging from this study were evaluated using the Student t-test. CONCLUSIONS: one-month exposure led to a decrease in hypothalamic NA and an increase in rat spleen weight; increase in CA concentration in the adrenals was initially insignificant, by the end of a 2-month exposure it reached the level of statistical significance; serum concentrations of B, T3 and T4 remained unaffected and so was the weight of the body, liver, lungs, suprarenals and the hypothalamus of exposed rats; at the concentrations used, NO2 and CO acted as synergists producing a mild stressogenic reaction affecting the activity of the sympathico-adrenomedullary system of exposed rats.