Résumé
The protective role of "essentiale phospholipids" (EPL) on mercury induced thyroid dysfunction with special reference to cholesterol, thyroid peroxidase and thyroxine activity in mice were investigated. The animals were treated with 0.5 ml/day of 0.5 ppm aqueous mercuric chloride for a period of 7, 14 and 21 days. For the recovery 175 mg of EPL was given to mice (already treated with HgCl2) for a period of 7, 14 and 21 days. Daily treatment of HgCl2 for 7, 14 and 21 days decreased serum cholesterol, TPO and T4 activity. Simultaneous administration of EPL (25 mg/mice) restored thyroid function in mice by maintaining serum thyroid hormone concentration almost normal. It increased serum cholesterol, TPO and T4 activity. It appears that the protective effect of EPL against HgCl2 induced thyroid dysfunction is mediated through its antioxidative action.
Sujets)
Animaux , Cholestérol/sang , Iodide peroxidase/sang , Chlorure de mercure II/administration et posologie , Souris , Phospholipides/administration et posologie , Récupération fonctionnelle/physiologie , Glande thyroide/effets des médicaments et des substances chimiques , Hormones thyroïdiennes/sang , Thyroxine/sang , Facteurs tempsRésumé
Intraperitoneal administration of methylmercury chloride (MMC) and mercuric chloride (MC) to male rats in doses of 5, 10 micrograms MMC/kg or 50, 100 micrograms MC/kg for 90 days induced cellular disintegration of Leydig cells which was conspicuous on day 30 and onwards in the exposed groups. Progressive degeneration of Leydig cells and decrease in their nuclear diameter and population were associated with gradual increase in deposition of mercury. Gradual diminution of 3 beta-hydroxy-delta 5-steroid dehydrogenase activity in Leydig cells after MMC or MC treatment was correlated with different structural deformations of the cells over 90 days. Moreover, a significant decrease in serum testosterone levels by day 90 confirmed steroidogenic impairment after MMC or MC treatment.