The Active Principles of the Pituitary Gland

Abstract

SINCE the discovery by Oliver and Schafer of the blood-pressure raising or pressor effect of extracts of the posterior lobe of the pituitary gland, a number of other phenomena caused by injections of this material have been described; thus although in mammals the blood-pressure is raised, in birds it is reduced; in the former the extract also stimulates the uterus to contract, and produces an increased flow of milk and an increased secretion of urine, under certain conditions, but under others the urinary flow is markedly diminished. In frogs the extract stimulates the pigment-carrying cells or melanophores to dilate, producing thereby a darkening of the skin of the animal. It may be noted that these active principles are all obtained from the non-glandular posterior lobe of the organ, which is composed chiefly of neuroglial tissue, although it has a partial investment of glandular cells from the pars intermedia. The glandular anterior lobe, which is essential for normal growth, has not yet yielded for certainty an active extract to the labours of the biochemist.