Effect of altered hormonal states on the histochemical distribution of lipase activity in the rat prostatic complex

Summary Lipase activity is localized mainly in the cytoplasm of the epithelial cells of all the rat prostatic lobes, and in periacinar stroma of the dorsal prostate; lateral lobe has little enzyme activity. Progesterone (1 and 2.5 mg) causes an increase in lipase activity in the acinar epithelia, periacinar and interfollicular stroma, blood vessels and the mast cells of the ventral prostate. A low dose of estrogen (0.1 g) markedly stimulates and a high dose (5 g) virtually obliterates the activity of the enzyme in the prostatic complex. Following cessation of progesterone therapy the enzyme activity is augmented still further, but near normalization is seen after withdrawal of estrogen. When the two steroids are given conjointly, an estrogenic pattern of morphology is the feature; at the same time there is some suggestion of an antagonism between the two hormones with respect to their effect on the enzyme. Thyroidectomy causes an increase in lipase activity of the complex which is not normalized after thyroxine therapy.Communication no. 1398. Part IX in the series Prostate and endocrines.