Contributions of clinical medicine to renal physiology.

The strong influence of clinical medicine on the development of renal physiology in the 20th century is a natural consequence of the striking disorders imposed by disease on the volume and composition of the fluids of the body. Clinicians well grounded in physiology were able to seize unusual opportunities provided by sick patients to elucidate principles of homeostatic control applicable to health as well as to disease. Three examples of such contributions, primarily originating at the bedside, are discussed: the role of potassium in metabolic alkalosis, the function of the parathyroid glands as exemplified by the syndrome of hyperparathyroidism, and the discovery of a humoral factor, distinct from parathyroid hormone, that may regulate phosphate excretion by the kidneys.