Effect of testosterone on fracture healing in hypophysectomized rats.

The effect of hypophysectomy and hypophysectomy + testosterone treatment on fracture healing was investigated on 60 Wistar rats (30 day old). The aim of the experiment was to elucidate whether in callus formation testosterone acts directly on the cells (peripheral effect), or its effect is mediated through the hypophysis (central effect). Changes induced by hypophysectomy take place in the course of callus formation due primarily to the impairment of the enzyme system of the cells. The effect of hypophysectomy can be attenuated with testosterone which, despite hypophysectomy, stimulates fracture healing. It may be concluded that testosterone exerts a direct peripheral effect on the callus cells, presumably on their enzyme system.