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Biomedical subjects

M Náray

Publications and source records attributed to M Náray.

27 records · Page 2Linked to original sources
PubMed1991

Distribution of cadmium in ovaries, adrenals and pituitary gland after chronic administration in rats.

Wistar rats were given 0.25, 0.5 or 1.0 mg/kg/week CdCl2 for 14, 18 or 22 weeks and the body weight, Cd content of ovaries, adrenals, pituitary gland, furthermore the progesterone and oestradiol-17 beta secretion of ovary were checked. Cd treatment caused a slight decrease in the body weight, but failed to alter the weight of endocrine organs. CdCl2 in a dose of 0.25 mg/kg/week resulted in almost the same Cd content in all the three organs. Rising the amount of Cd administered the pituitary gland accumulated more Cd than the adrenals, and the lowest levels were found in the ovary. CdCl2 even in the dose of 1.0 mg/kg/week failed to alter the ovarian cycle, progesterone and oestradiol-17 beta production of ovary. The data point also to a developing tolerance to Cd as the cumulative dose of CdCl2 lies close to the LD50 levels.

Adrenal Glands↗
PubMed1990

Uptake and distribution of Cd in the ovaries, adrenals, and pituitary in pseudopregnant rats: effect of Cd on progesterone serum levels.

Pseudopregnant (PSP) rats were treated with 3.5 or 7.0 mg/kg body wt of CdCl2 on Day 1 of PSP sc. In the lower dose Cd content of the ovaries (luteal and nonluteal tissues), adrenals, pituitary, and blood on Days 1, 2, 5, 8, 10, and 12, and in the higher dose that of luteal and nonluteal tissue on Days 2 and 5 of PSP were determined with atomic absorption spectrophotometry. A rapid incorporation into the corpora lutea was measured on Day 1 and Day 2 of PSP followed by a decrease of Cd content toward the end of PSP whereas the nonluteal tissue, adrenals, and pituitary accumulated Cd gradually until the fifth to 10th day, respectively. Progesterone (P) serum levels were measured with RIA in the blood collected daily from the jugular vein following administration of 3.5 to 7.0 mg/kg body wt of CdCl2 sc on Day 1 or Day 8 of PSP. The serum levels of P remained unchanged when CdCl2 was administered on Day 1 of PSP; however, 7.0 mg/kg body wt CdCl2 given on Day 8 of PSP induced a significant decrease in serum levels of P. It is supposed that the regressing luteal tissue is more sensitive to the toxic effects of Cd than the developing one.

Adrenal Glands↗
PubMed1986

Changes in the rat's motor behaviour during 4-hr inhalation exposure to prenarcotic concentrations of benzene and its derivatives.

Group motility was recorded continuously in male rats during the inhalation of benzene, toluene, ethylbenzene, o-, m- and p-xylene vapours. The solvents were applied in at least six concentrations, up to those inducing anaesthesia. Minimum narcotic concentrations (ppm) were: 5940 (benzene), 3590 (toluene), 2180 (ethyl-benzene), 2180 (0-xylene), 2100 (m-xylene), and 1940 (p-xylene). The results indicate that prenarcotic concentrations of these structurally related aromatic hydrocarbons and also the xylene isomers elicit qualitatively and quantitatively different acute behavioral effects. Except o-xylene which caused depression only the agents produced bell-shaped concentration-action curves characteristic of the biphasic effect, i.e., activation at lower and depression at higher concentrations. The curves differed in form and magnitude depending on the stimulatory potency and on the range of effective concentrations. Based on arbitrary assessment of central excitation, the five aromatics may be ranked as follows: benzene and toluene (striking activation), p-xylene (marked activation), ethylbenzene (moderate activation), m-xylene (slight activation). At the same time, high degree of motor incoordination, and in the case of benzene and p-xylene, also marked tremor could be seen.

Animals↗
PubMed1982

Comparative study on the acute effects of benzene, toluene and m-xylene in the rat.

Solvents were tested for their influence on motivational state, as well as for their sedative effects, after intraperitoneal administration. The following tests were used: open field (exploratory activity, locomotion), activity wheel (running activity), tube test and tilted plane (muscle weakness, incoordination). The agents proved to be similar in causing muscle weakness and ataxia already at low dose levels. Benzene was the most potent in this respect. The three solvents, however, contrasted strongly in influencing motor activity. While benzene and especially toluene exerted CNS stimulation, no such effect could be detected following m-xylene treatment. On the basis of human experiences with these substances it may be suggested that the screening procedure applied in rats might be useful for predicting acute adverse effects in man.

Acute Disease↗
PubMedDate not supplied

Combined pulmonary toxicity of diethyldithiocarbamate and lead (II) oxide in rats.

The pulmonary toxicity of sodium diethyldithiocarbamate and lead(II) oxide alone or in combination was studied in rats after a single intratracheal instillation. The lead content in the lungs and the whole blood was determined and it has been found that the clearance of lead from the lung was delayed by dithiocarbamate complex formation, which probably had a role in increased IgA levels in the bronchoalveolar fluid and the induction of local immune response. The combined exposure gave rise to calcium deposits in the lungs both extra- and intracellularly after 1 month of exposure. Both separate and combined exposure invoked permanent injury in membranes or dystrophic changes in the cytoplasm of pneumocytes, which may initiate and generate a series of events leading to fibrosing alveolitis.

Adjuvants, Immunologic↗
PubMedDate not supplied

Combined pulmonary toxicity of cadmium chloride and sodium diethyldithiocarbamate.

The pulmonary toxicity of sodium diethyldithiocarbamate and cadmium chloride, each separately and in combination, was compared in Sprague-Dawley rats after single intratracheal instillation in sequential experiments by chemical, immunological and morphological methods. With combined exposure, the cadmium content of the lungs increased permanently relative to that of the lungs of just cadmium-treated animals. Immunoglobulin levels of the whole blood did not change, whereas in bronchoalveolar lavage the IgA and IgG levels increased significantly. Morphological changes were characteristic of the effects of cadmium but were more extensive and more serious than in the case of cadmium administration alone: by the end of the first month, interstitial fibrosis, emphysema and injury of membranes of type I pneumocytes developed and hypertrophy and loss of microvilli in type II pneumocytes were detectable. These results showed that although dithiocarbamates as chelating agents are suitable for the removal of cadmium from organisms, they alter the redistribution of cadmium within the organism, thereby increasing the cadmium content in the lungs, and structural changes are more serious than observed upon cadmium exposure alone.

Animals↗
PubMedDate not supplied

Age dependent accumulation of cadmium in the human ovary.

Cadmium (Cd) was determined by atomic absorption spectrophotometry in small pieces (< 1 g) of healthy human ovaries excised for histologic examination. Cd levels in the ovary increased linearly between 30 and 65 years of age. Below 30 years, there was no age dependent increase and over 65 a tendency was observed for ovarian Cd levels to decrease. There was no difference in the Cd content of fresh luteal and nonluteal tissue taken from regularly cycling ovaries. In smokers, the amount of Cd in the ovaries was elevated compared to nonsmokers. In multiparous women (more than 3 children) a tendency of decreased Cd ovarian levels was observed. There was no difference between ovarian Cd content of physical and mental workers. It can be proposed that Cd may be a risk factor for conception and pregnancy in women in their forties.

Adolescent↗