Bone activity under the influence of estrogen replacement alone and with testosterone in ovariectomized rats

ABSTRACT

Replacement therapy with estrogen alone or in combination with testosterone was studied in ovariectomized rats. Bone activity was estimated by serum alkaline phosphatase, calcium and parathyroid hormone and urinary excretion of calcium. It was found that estrogen replacement resulted in considerable fall in serum calcium [14-18%], alkaline phosphatase [20-25%] and urinary calcium/creatinine ratio [28-34%]. Administration of estrogen combined with testosterone resulted in more decrease in all of these values. Parathyroid hormone returned to normal serum level after estrogen therapy and significantly increased more than normal levels after the combined therapy. These results proved that replacement therapy with estrogen in combination with testosterone is more effective than estrogen alone in treating osteoporosis after oophorectomy