Variations in the contents of calcium, phosphate, magnesium and sodium in bones of castrated male rats.

Bilateral castration (TX) or sham surgery -respectively- was performed in two groups of twelve male Holtzman rats, 90 days old. Food was available ad libitum to sham-operated rats, and it was restricted to TX ones. After castration, at 30, 60, 90, 120 and 150 days, a segment of the rails was sectioned. At 150 days all rats were subjected to bone mineral densitometry (BMD), sacrificed and the left femurs excised. With the tail's bones (TB) and the femur we determined ash and the concentration of Ca++, PO4-3, Mg++ and Na+. In the TB, at 30 days the ash and the concentrations of Ca++ and PO4-3 decreased (p<0,05) in the TX rats. At 60 days the ash and all analysed ions were reduced (p<0.05 and p<0.025) in the TX rats. The decreases were major forward. The more significative decreases in the TB were: in Ca++ at 90 days (p<0.005); in the ash at 120 days (p<0.005); in PO4-3, Mg++ and Na+ at 150 days (p<0.005). All ions' concentrations and the ash were statistically equal between the TB and the femurs after 150 days of castration. At the same time, the BMD was significantly less (p<0.05) in the TX rats. The body weigh of the two group was statistically equal during the 150 days. Our results suggest that in 90 days old castrated male rats, the ash and the concentration of calcium, phosphate, magnesium and sodium in the TB are good indicators of bone mass loss, after 30 and 60 days of castration. Besides, 150 days post castration, the ash and the analysed ions are equal in the femur and in the TB. Moreover, the ions' concentrations were betters indicators of the bone mass loss than the BMD.