Effects of prolactin on osteoblast alkaline phosphatase and bone formation in the developing rat

Djurdjica Coss, Lili Yang, Chiaoyun Benson Kuo, Xiaolei Xu, Richard A. Luben, Ameae M. Walker
2000 American Journal of Physiology. Endocrinology and Metabolism  
Effects of prolactin on osteoblast alkaline phosphatase and bone formation in the developing rat. Am J Physiol Endocrinol Metab 279: E1216-E1225, 2000The purpose of the current study was to determine whether maternal prolactin (PRL) had any effects on bone formation in the developing rat pup. Because the most prevalent forms of PRL in rats are unmodified and phosphorylated PRL, both recombinant PRL and a molecular mimic of phosphorylated PRL (PP-PRL) were administered to pregnant animals. Blood
more » ... nant animals. Blood samples from the dams showed normal estrogen and progesterone and no effect of extra PRL on parathyroid hormone (PTH), calcium, or alkaline phosphatase (AP). In newborn pups, however, there was a 30% decrease in blood AP in both PRL-treated groups, whereas PTH and calcium levels were not different from controls. When primary rat osteoblasts were exposed to both PRLs, AP activity was reduced, with PP-PRL being the more potent form of the hormone. Histological examination of pup bone formation showed reduced calvarial bone and reduced endochondral ossification in pups exposed to PP-PRL. These results are the first to show a direct inhibitory effect of PRL on osteoblast function. phosphorylated prolactin; intramembranous bone formation; endochondral bone formation Address for reprint requests and other correspondence: A. M. Walker,
doi:10.1152/ajpendo.2000.279.6.e1216 pmid:11093907 fatcat:jvkv65xyjnc6forjzo56ezeo3u