The influence of orchidectomy on collagen glycosylation of trabecular bone in rat

This study evaluates the effect of male rat castration on the degree of collagen glycosylation of bone. Twenty 100-day-old male Sprague-Dawley rats were subjected to either orchidectomy (n = 10) or sham operation (n = 10). After surgery animals were divided at random into 2 groups: the first group (5 sham operated and 5 orchidectomized) was sacrificed under anaesthetic at 130 days of age, while the second group (5 sham operated and 5 orchidectomized) was sacrificed at 250 days of age. Femurs and tibiae were separated into cortical and trabecular bone, demineralized, hydrolyzed and analyzed by HPLC for hydroxylysine glycosides and hydroxyproline content. Orchidectomy causes an increased collagen glycosylation only in trabecular bone, as already observed in ovariectomized rats. However, the effect was not seen in the group of 130 day old rats, i.e. 30 days after orchidectomy, but was evident in the 250 day old rats, i.e. at 150 days from castration. These data suggest that collagen glycosylation could also be controlled by testosterone.