Effect of Progesterone Pretreatment on Cadmium Toxicity in Male Fischer (F344/NCr) and Wistar (WF/NCr) Rats

Abstract

A previous report indicated that progesterone pretreatment can markedly reduce cadmium (Cd) toxicity in male NAW mice. Therefore we examined the effects of progesterone pretreatment on Cd toxicity in male Fischer (F344) and Wistar (WF) rats. A single subcutaneous injection of 10 or 30 pmole (CdCI2)/kg proved nonlethal over 24 hr but caused the typical spectrum of testicular lesions in these rats. Moreover, when F344 rats were pretreated with progesterone (100 mg/kg, sc, at -48, -24, and 0 hr) and then given cadmium (20 pmole CdCI2/kg, 0 hr), this dose of cadmium proved very toxic, unexpectedly causing 53% mortality. Progesterone pretreatment had no effect on cadmium-induced lethality in WF rats or on testicular lesions in either strain. Significant elevations in serum lactate dehydrogenase (LDH) activity, indicative of hepatotoxicity, were also observed in progesterone-pretreated F344 rats given cadmium as compared to rats given Cd alone. Progesterone did not induce increases in hepatic or renal metallothionein (MT) and hepatic or testicular MT-I mRNA levels in F344 rats. In contrast, levels of the testicular cadmium-binding protein (TCBP) in progesterone-pretreated F344 rats were doubled. This increase in TCBP provided no protection against cadmium toxicity in the testes. These results indicate that, in contrast to previously reported data for mice, progesterone pretreatment increased the lethality of cadmium in male F344 rats and had no effect on cadmium-induced testicular toxicity in F344 and WF rats. -Environ Health Perspect 1 02(Suppl 3): 277-280 (1994).

Diabetes Mellitus induces alterations in metallothionein protein expression and metal levels in the testis and liver

“…These data suggest there are organ-specific patterns of diabetes-induced MT expression in the early stage of diabetes in rats. Similar to previous findings, 26,27,28,29 we revealed that the testicular MT protein levels were much higher than the hepatic MT in the Ctrl group, indicating that the antioxidant capacity of the testis may be higher than that of the liver. The basal difference in MT expression between the two organs may explain why we did not observe an obvious change in testicular MT protein in the relatively early stage of diabetes (30 days).…”