The program of the Specialized Center of Research in Hypertension has been broadened to provide a spectrum ranging from molecular events in the initiation of hypertension, through behavioral, normal, nervous and renovascular changes in the development of hypertension in animals and man, to the possible prevention of the hypertension, the pharmacology of antihypertensive drugs, the treatment of early and malignant hypertension, and a study of the on-the-job blood pressure patterns of air-traffic controllers. Studies are in progress on the nature and mode of functioning of the adrenergic receptors for catecholamines, the localization, isolation and purification of renin, mechanisms controlling renin secretion, the efficiency of inhibitors of renin and the converting-enzyme in prevention and treatment of hypertension, behavioral factors in the development of hypertension in monkey and man, the role of renin-angiotensin-aldosterone-vasopressin in the initiation of renovascular hypertension, pharmokinetics and metabolism of anti-hypertensive drugs, and evaluation of antihypertensive drugs administered singly or in combination. At each end of the spectrum, new approaches have recently been added to the program: (1) The experience gained in studying the induction of hypertension in squirrel monkeys by operant conditioning will be extended to man in a unique laboratory-like setting. the air-traffic control tower of a busy airport, and (2) the application of a potentially powerful new analytic tool, the electronprobe microanalyzer.