Effect of Extracts of Pars Tuberalis of Hypophysis on Urine Secretion.

Abstract

Saline suspensions or boiled acidulated extracts of the bovine pars tuberalis when injected intravenously into rabbits under paraldehyde anesthesia produce a diuresis differing from that produced by injection of posterior lobe extracts. The resulting diuresis comes on without a marked rise of blood pressure and without the latent period of 3 to 5 minutes (during which the flow of urine is entirely suppressed) which are characteristic accompaniments of posterior lobe diuresis. Diabetes insipidus is held, to be due to injury of the base of the brain in the region of the tuber cinereum. Critical examination of the figures of Bailey and Bremer, and of Curtis, shows that in practically every instance the injury has involved the pars tuberalis of the hypophysis. Bourquin has shown that experimental diabetes insipidus in dogs is an irritation rather than a deficiency phenomenon. Slight cauterization of the floor of the third ventricle produces the diabetes but deeper cautery destroys it. She further concludes that “the diuresis must be due to a substance produced at the site of the causative disturbance” for the diabetes insipidus “runs its typical course after trans-section of the spinal cord at the level of the eighth cervical vertebra, double vagotomy below the diaphragm, and paralysis of the parasympathetic nervous system with atropin.” If the cause of experimental diabetes insipidus is to be ascribed to the irritative production of a hormone in the floor of the third ventricle, it is no less reasonable to suppose that the hormone is derived from the pars tuberah, which is distinctly a glandular structure, than that it is produced by brain tissue.