Effects of short‐day photoperiods and of castration on the structural integrity of the ventral and dorsal prostates of the Syrian hamster (Mesocricetus auratus)

Abstract

Short-day photoperiods and castration both cause reductions in the weights of male accessory sex glands. In the Syrian hamster, we have found that the ventral prostate loses less weight following these treatments than does the dorsal prostate. In this paper, we report on the effects of the pineal and of castration on the structural integrity of these glands, as assessed by stereological techniques. Short days result in little alteration to the ventral prostate or its acinar composition. The typical acinus is narrower following 10 weeks in short days. The ventral prostate also responds to castration with a narrower acinus, and, in addition, it shows a decrease in the epithelial volume fraction and increases in those of the lumen and muscular stroma. In neither case is there a change in the proportion of the gland consisting of acinar or interacinar components. Short-day photoperiods and castration generally show similar effects in the dorsal prostate. In both cases, there are increases in the proportion of the gland made up of interacinar tissue. Within the acini, there are decreases in the volume fractions of lumen and large increases in those of lamina propria and muscular stroma. Following both treatments, typical acini are narrower and show reduction in the thickness of the epithelium and increases in the thickness of the lamina propria and muscular stroma.Thus, in the ventral prostate, both short days and castration lead to subtle changes which are different with each treatment and which differ from those that occur in the dorsal prostate. In the dorsal prostate, there are relative increases in the proportions of nonepithelial elements following both of these treatments. These results are discussed in relation to the mode of action of the pineal in causing accessory sex gland regression.