The Role of Hormones in the Regulation of Bone Turnover and Eggshell Calcification
Published on Jan 1, 2015
· DOI :10.1016/B978-0-12-407160-5.00025-7
Birds, particularly chickens and Japanese quail, have made an important contribution to our understanding of bone and calcium (Ca) metabolism in vertebrate species, including humans. This chapter reviews and updates actions of classical bone- and Ca-regulating factors, including parathyroid hormone, calcitonin, and their related peptides, PTHrP, PLP, CGRP, and amylin. The important roles of the vitamin D system, gonadal steroids, and paracrine factors including prostaglandins are also included. Recently recognized factors which act on the skeleton, including the RANK–RANKL system and osteopontin, are also reviewed in relation to avian Ca and bone metabolism. Important hormonal target tissues including bone and bone cells, gut, kidney, and eggshell gland are considered. The evolution, organization of avian medullary bone, and hormonal actions on this specialized labile Ca store and its role in eggshell calcification form an important part of this chapter.