thromboxane-b2 and methylmercury-hydroxide

The effects of methylmercury hydroxide' (MeHg), atrazine, and dietary methionine on the activity of blood glutathione peroxidase (GSH-Px), total blood glutathione (TGSH) level, and the ex-vivo synthesis of prostaglandin E1 (PGE1) and thromboxane B2 (TXB2) by platelets from clotted blood in rats were studied. One-month-old male Wistar rats were fed different diets (60, 100 or 140% of sulfur amino acids requirement) and treated with atrazine (0 or 500 mg/kg diet), MeHg (0, 0.5 or 1.5 mg Hg/kg/day) orally, or a combination of the two toxicants for 30-35 days. Blood was analyzed for glutathione peroxidase (GSH-Px), total mercury, TGSH, PGE1, and TXB2. The concentration of mercury in the blood was significantly affected by MeHg treatment as well as by its interaction with dietary methionine. Increasing MeHg dose in the diet decreased the activity of whole blood GSH-Px and total blood GSH while increasing ex-vivo synthesis of PGE1 and TXB2. Methionine deficiency caused a slight increase in serum PGE1 level. Overall factorial analysis for TXB2 revealed a highly significant effect of MeHg and methionine as well as their interaction on serum TXB2 level. The effect of atrazine on PGE1 and TXB2 levels was not statistically significant. The possible mechanisms of increased serum PGE1 and TXB2 levels due to MeHg toxicity are discussed.

Topics: Alprostadil; Animals; Atrazine; Blood Platelets; Diet; Drug Interactions; Glutathione; Glutathione Peroxidase; Male; Mercury; Methionine; Methylmercury Compounds; Prostaglandins E; Rats; Rats, Inbred Strains; Thromboxane B2; Thromboxanes