Architecture of the dorsal and ventral lobes of the prostate of the Syrian hamster, Mesocricetus auratus, after regrowth from short day-induced regression

Abstract

The structures of the dorsal and ventral lobes of the prostate of 4 groups of Syrian hamsters were studied by a stereological approach. Groups studied were young hamsters (kept in long-day photoperiods for 4 weeks) in their first breeding season, older hamsters (kept in short-day photoperiods for 24 weeks so that their prostates had regressed and regrown) in their second breeding season, and two groups of older hamsters in an extended first breeding season (either because they were kept in long days for 24 weeks or because they were pinealectomized before being put into short-day photoperiods for 24 weeks). There were very few differences between groups, but generally dorsal prostates of older hamsters in their second breeding season closely resembled those of young hamsters in their first breeding season. More differences were noted between either of these two groups and older hamsters in an extended first breeding season than between these two groups. The differences noted generally involved increases in the amount of smooth muscle in the walls of secretory tubules in the dorsal prostates of hamsters in an extended first breeding season. This may be associated with the fact that these glands had not regressed and regrown. Ventral prostates were very similar in all 4 groups, which may reflect the fact that they normally regress very little in short days.

Photoperiod‐induced apoptosis in the male genital tract epithelia of the golden hamster

“…, 1995), although in the rat it is the ventral lobe that undergoes the most dramatic changes. Nevertheless, in the hamster, it is the dorsal lobe that undergoes the most profound changes during regression (Buzzell, 1989) which is in agreement with our results. These responses to photoperiod must be reflecting in some way the changes in testosterone levels.…”