Abstract
Experimental hens producing soft-shelled eggs were established, in which secretion of egg-shell calcium was suppressed by ligation of the uterus of the oviduct with a loop of a string. X-ray and histological observations were made of the distribution and stucture of medullary bones of these experimental hens.
Medullary bones were distributed all over the medullary space and showed increased width and curved lamellar structure. Matrix of medullary bones was poor in acid mucopolysac-charide, rich in collagen fibers, and bone salts were also abundant. Each of osteoblasts, osteoclasts and osteocytes was small in number, and the proportion of atrophic cells was large. The alkaline phosphatase activity of osteoblasts, the acid phosphatase activity of osteoclasts and osteocytes and the succinate dehydrogenase activity of each of these cells were weak, and cellular functions of these cells were also decreased.
The results suggested that calcium metabolism of medullary bones is decreased in hens of which calcium-secreting function at the uterus of the oviduct is experimentally suppressed.
