The influence of prolactin on bone mineral density (BMD) and some biochemical markers of ovariectomized rats.

A model of postmenopausal osteoporosis was used in the study. 107 days after ovariectomy the animals were subcutaneously applied 1.0 IU PRL/kg BM or 1.0 IU calcitonin/kg BM for 7 days in single doses. The application of the preparations started again 80 days after the first application. After 194 days the animals were narcotized, blood was collected, and lumbar (L2-L4) and femoral bones were prepared. The material obtained was subjected to densitometric analysis of bone mineral density (BMD). In ovariecto - mized rats the loss of osseous tissue was observed only in the lumbar bone. The application of prolactin to ovariectomized rats caused an increase in the mineral density of the lumbar bone up to a BMD value equal to that of the control group which had not been subjected to ovariectomy (control healthy group - SHAM). Similar results were obtained in the case of calcitonin. An increase in osteocalcin concentration and activity of isoenzyme alkaline phosphatase (BAL), with a decrease in the activity of isoenzyme acid phosphatase (TRAP) was observed in experimental groups compared to control ones.