neanthine and methylmercuric-chloride

The toxic effects of mercuric chloride (HgCl2), emisan 6 (a methoxy-ethyl mercury fungicide), and methyl mercuric chloride (CH3HgCl) on the adrenocortical-pituitary activity of the catfish were investigated after 45, 90, and 180 days of exposure. The adrenocortical cells were highly stimulated in the 90-day HgCl2 group and became hyperplastic in the 180-day group. These cells were active in the 90-day emisan 6 group, with the infiltration of lymphocytes and fibrosis in the 180-day group. In the 90-day CH3HgCl gropu, the cells were active, with lymphocytic infiltration, fibrosis, and necrotic changes in some areas. In the 180-day CH3HgCl group, there was an extensive infiltration of lymphocytes, with localized sites of necrosis and hyperplasia. The ACTH cells in the pituitary were hypertrophied and degranulated in the Hg-treated groups, suggesting increased secretion of ACTH. The plasma cortisol level decreased significantly in the 90- and 180-day Hg-exposed groups in a time-dependent manner. Of the three mercurials, CH3HgCl is the most toxic in reducing the plasma cortisol level in all durations. These results suggest that Hg impairs the adrenocortical-pituitary activity of the catfish.

Topics: Animals; Catfishes; Ethylmercuric Chloride; Female; Fungicides, Industrial; Hydrocortisone; Male; Mercuric Chloride; Methylmercury Compounds; Pituitary-Adrenal System

Topics: 3-Hydroxysteroid Dehydrogenases; Animals; Catfishes; Ethylmercuric Chloride; Fungicides, Industrial; Male; Mercuric Chloride; Mercury; Methylmercury Compounds; Testis

In Clarias batrachus methylmercuric chloride (CH3HgCl) was 1.18 and 10.05 times more toxic than mercuric chloride (HgCl2) and emisan 6 (methoxyethyl mercury chloride), respectively, for 96 hr. A similar trend was observed at 24, 48, and 72 hr. Exposure of the catfish to sublethal concentrations of these mercurials for 14 and 28 days caused progressive changes in the kidney. The diameter of the proximal convoluted tubules was increased, the epithelial cells were hypertrophied, and the lumen was reduced and filled with secretory material and sloughed-off cells. In 14-day emisan 6-treated fish, some glomeruli were also degenerated. Exposure of the catfish to toxicologically safe concentrations of the mercurials for 90 days caused vacuolation, atrophy, and extensive damage of the tubules in HgCl2-and CH3HgCl-treated fish, and hypertrophy and vacuolation of epithelial cells of some tubules in the emisan 6-treated fish. Regeneration was noticed in the 90-day HgCl2-exposed group. After 180 days of exposure, however, histology of the kidney appeared normal in all the groups.

Topics: Animals; Biological Assay; Catfishes; Ethylmercuric Chloride; Ethylmercury Compounds; Female; Kidney; Male; Mercuric Chloride; Methylmercury Compounds