Medullary Bone Formation Research Articles

Influence of Large Doses of Œstrogens on the Structure of the Bones of Some Reptiles

IT was first shown by Kyes and Potter1 that, during reproductive activity, the marrow cavities of the bones of female pigeons become filled with endosteal bone. It is thought that this medullary bone is formed under the synergistic action of the androgens and œstrogens2 which are produced in the female bird during the breeding season. Similarly, injections of œstrogens induce the formation of medullary bone in male birds. Medullary bone differs from cortical bone histologically3,4, and it appears to act as a labile calcium store which can be mobilized rapidly during the formation of the eggshell.

THE PARTITION OF PLASMA CALCIUM AND INORGANIC PHOSPHORUS IN ESTROGENTREATED NORMAL AND PARATHYROIDECTOMIZED PIGEONS

IN OVIPAROUS VERTEBRATES each period of egg production is associated with a large increase in the non-ultrafiltrable fraction of the plasma calcium. Similar and evengreater increases in total plasma calcium of these vertebrates result from the administration of estrogens, but in these cases the partition of calcium has not been determined. The literature on this subject has been reviewed by Riddle (1942) and by Gardner and Pfeiffer (1943). A recent study by Riddle, Rauch and Smith (1945) has shown that parathyroidectomy has little or no effect on the ability of estrogens to cause hypercalcemia and medullary bone formation in the pigeon. Many of the same animals used in that investigation were further utilized for the present study of the partition of calcium and inorganic phosphorus in the plasmas of estrogen-treated pigeons.

Calcification and ossification. The formation of medullary bone in male and castrate pigeons under the influence of sex hormones

Calcification and ossification. The formation of medullary bone in male and castrate pigeons under the influence of sex hormones