Modified expression of steroid 5 alpha-reductase as well as romatase, but not cholesterol side-chain cleavage enzyme, in the reproductive system of male mice during (Taenia crassiceps) cysticercosis

Infection with Taenia crassiceps cysticerci in male mice produces an increa se in serum estradiol levels? whereas serum testosterone is abolished. Conc omitantly, complete atrophy of the reproductive tract of infected male mice is observed. The present study was undertaken to determine the expression pattern of three key steroidogenic enzymes in the reproductive tissues of n ormal and infected male mice. In infected mice, serum estradiol levels were increased 97 times as compared with control mice of the same age. Testoste rone and dihydrotestosterone levels were completely inhibited. The expressi on of Sa-reductase in the reproductive tract was markedly reduced, whereas aromatase mRNA levels were highly elevated in the testes of parasitized mic e. No change in the mRNA content for cholesterol side-chain cleavage enzyme was evident. The overall results suggest that the change in the normal pro duction of sex steroids in infected male mice is produced concomitantly by the inhibition of expression of the 5 alpha-reductase enzyme and the activa tion of aromatase gene expression. This induces a preferential metabolism f rom testosterone to estradiol instead of the normal metabolism from testost erone to dihydrotestosterone.