[Interrelation between the hypothalamic arcuate nucleus and the bone variation of osteoporosis in rats]

This study investigated the interrelation between the hypothalamic arcuate nucleus (ARC) and the bone variation of osteoporosis in rats. Four animal models of ovariectomy-induced osteoporosis (OVX), glucocorticoid-induced osteoporosis (GIOP), retinoic acid-induced osteoporosis (RAOP) and senile osteoporosis (SOP) were used to study the influence of osteoporosis on ARC. Ovariectomized rats were further treated with thymopeptide, ciclosporin and exercise respectively to detect the changes of ARC nerve cells number. The results showed that: (1) The OVX, GIOP, RAOP and SOP models were successfully established, showing osteoporosis as well as decrease of the number of ARC nerve cells; (2) Thymopeptide and exercise respectively alleviated the bone loss induced by ovariectomy, accompanied by increase of the number of ARC nerve cells, while ciclosporin further increased the bone loss of ovariectomized rats, accompanied by further decrease of the number of ARC nerve cells. These results suggest that there is a close interrelationship between ARC and osteoporosis in rat. There is a hypothalamus-pituitary-bone (HPB) axis, and HPB axis regulates the mechanism of osteoporosis in rats.