Growth and bone haemodynamic responses to castration in male rats. Reversibility by testosterone
Schoutens, A.; Verhas, M.; L'Hermite-Baleriaux, M.; L'Hermite, M.; Verschaeren, A.; Dourov, N.; Mone, M.; Heilporn, A.; Tricot, A.
Acta Endocrinologica 107(3): 428-432
1984
ISSN/ISBN: 0001-5598 PMID: 6507008 Document Number: 226614
Orchidectomy in postpubertal 55 day old rats, compared to sham-operated controls, led beyond 2 mo. to a decrease in body weight (87% of controls by 120 days), tibial length (97% of controls) and in tibial Ca content (85% of controls). Bone plasma flow increased 3 times to reach a peak at 31 days; it was decreased but not significantly at 86 and 120 days. The number of osteoclasts was maximal at 51 days (.times. 2.3) and was still elevated at 120 days. The Ca accretion rate increased briefly at 31 days (110% of controls) and was diminished at 86 and 120 days (78% of controls). The initial physiological changes in the tibia occurred before any weight change and might be directly due to the lack of androgens. They can be interpreted as inducing the conditions for enhanced bone resorption. Testosterone replacement therapy, initiated after the initial hemodynamic response, inhibited the negative effect of castration on bone growth.