Effect of adrenalectomy on cadmium- and turpentine-induced hepatic synthesis of metallothionein and α2-macrofetoprotein in the rat

Abstract
Recent reports have strongly implicated glucocorticoids in the induction of hepatic metallothionein synthesis and hypozincemia which occurs in certain pathophysiologic conditions. Studies were performed in rats to determine the effect of adrenalectomy and glucocorticoid treatment on the hepatic accumulation of metallothionein subsequent to the administration of cadmium and turpentine, two diverse substances known to induce hypozincemia and hepatic synthesis of metallothionein as well as α2-macrofetoprotein in intact rats. By 24 h, both substances induced significant hypozincemia, hepatic metallothionein accumulation, and a severe tissue inflammatory response in adrenalectomized rats. Adrenalectomy only prevented the increase in plasma α2-macrofetoprotein concentration. Results indicate that hepatic synthesis of α2-macrofetoprotein, but not metallothionein, is mediated by adrenal hormones. Thus, glucocorticoids do not play a “vital” role in hepatic metallothionein accumulation or hypozincemia induced by inflammatory stress, as previously postulated.