The part played by the hypothalamus and pituitary gland in the control of renal excretion

Abstract

The main established facts and the lines of approach that various workers have taken to the solution of the problem of renal control have been set out. The posterior pituitary hormone, with its stimulus to tubular reabsorption, has satisfied experimental and clinical investigation; and the linking of the hypothalamus to the posterior pituitary in a renal control complex is well established. It is possible that the supraoptico-hypophysial tract is nutritive only to the secretory pars nervosa cells, but it seems unlikely. There is little doubt that the anterior pituitary is an equally important agent in control; and on a slender basis of work not yet complete, it is suggested that the active agent is hormonal rather than metabolic, and that its action is upon the glomeruli. It may be that it increases filtration by calling into action a number of the glomeruli which we know to be resting in the normal kidney.It seems possible to advance a tentative view of the whole problem as an autonomic system in balance between a sympathetic anterior pituitary hormone and a parasympathetic posterior pituitary one; between renal filtration and renal reabsorption as the ultimate mechanism of urine variation, controlled each by its autonomic agent. That emotion, sleep and anaesthesia profoundly affect the pituitary machinery makes a cortical control an established fact; but the details of that control have not yet been properly grasped by experiment.The very delicate and complex problem of mammalian excretion, with its simultaneous need for conservation and rejection has built up an equally delicate and complex answer in this balanced and duplicated control, and one can only solve it piecemeal and slowly.