Impact of altered thyroid hormone status on prostatic glycosidases

Abstract

The impact of hyper‐ and hypothyroidism on prostatic glycosidases was investigated. Hyper‐thyroidism was induced by administering L‐thyroxine (25 μg/100 g body weight/day) for 60 days and hypothyroidism was induced by total thyroidectomy. To test the direct influence of thyroid hormones, prostatic lobes were incubated with different concentrations (10, 25 and 50 ng/mL) of T 3 and β‐N‐acetylglucosaminidase and β‐N‐acetylgalactosaminidase were assayed. Serum levels of thyroid hormones, oestradiol and testosterone increased in hyperthyroid, and decreased in hypothyroid rats. TSH decreased in hyperthyroid, and an opposite trend was seen in thyroidectomized, rats. Prostatic [anterior (coagulating glands), dorsolateral and ventral prostates] β‐glucosidase, β‐galactosidase, β‐N‐acetylglucosaminidase and β‐N‐acetylgalactosaminidase activities increased uniformly in hyperthyroid, and decreased in thyroidectomized, rats. In vitro studies showed a dose‐dependent stimulatory effect of T 3 on β‐N‐acetylglucosaminidase and β‐N‐acetylgalactosaminidase in all three lobes of the prostate. From the present study, it is concluded that hyperthyroidism augments and hypothyroidism inhibits prostatic glycosidases and T 3 has a direct stimulatory effect on these enzymes.