Steroid 5β-Reductase Activity in the Livers of Rats administered with Lead Acetate

Abstract

The increase of urinary δ-aminolevulinic acid in lead poisoning is well observed. In this paper, the effects of lead acetate on the activities of Δ4-reductase and 5β-reductase to cortisol, cortisone, testosterone and Δ4-androstene-3, 17-dione and of dehydrogenase to 3α-hydroxysteroid and 3β-hydroxysteroid were examined. To measure the activities, 12, 000×g and 105, 000×g supernatant of rat liver were used.The Δ4-reductase activity to cortisol and testosterone showed a significant decrease twenty-four hours after the administration of lead acetate, but that to testosterone showed a remarkable increase seventy-two hours after the administration of lead acetate.The 5β-reductase activity to testosterone decreased significantly twenty-four hours after the administration of lead acetate, but increased seventy-two hours after administration of lead acetate. No significant difference was found in Δ4-androstene-3, 17-dione.From these results, it was suggested that steroid 5β-reductase activity was an important factor in affecting the heme synthesis in lead poisoning.