Ann M. Budy

Species Differences in the Reaction of the Mammalian Skeleton to Estrogens.

Summary Estrogenic steroid hormones stimulate endosteal bone formation and inhibit bone resorption in mice. In young growing rats, the same substances do not produce endosteal bone but interfere with endochondral ossification by inhibiting resorption of cartilage matrix and new bone. In other rodents, such as hamsters, guinea pigs, and rabbits, and also in cats and dogs, there is no apparent specific effect of estrogens upon formation of bone.

Chemistry and Physiology of the Parathyroid Hormone

Publisher Summary During the year 1960, some 35 years after the first preparation of an active extract of the parathyroid glands, the chemistry and physiology of the parathyroid hormone entered a new era. For the first time the hormone was isolated in pure form and characterized, and small amounts were made available for experimental purposes, supplementing the crude extracts upon which virtually all the work on the physiologic activity of the hormone had been based. Work with the purified hormone has already clarified some important problems, and it may be confidently expected that other major advances will follow. Between 1925 and 1960, there were many efforts to extract and purify the active principle of the parathyroid glands; that they were not completely successful until recently was owing in part to the difficulties inherent in the procedures and to the degradation of the hormonal molecule during extraction, and in part also to the need of modern instrumentation for extraction and separation of substances in solution. Hot dilute hydrochloric acid and hot concentrated acetic acid were used successfully for extraction of hormonal activity from minced glands, but not without damage to the molecule. Aurbach developed a superior extraction method using aqueous phenol solutions.