Systemic circulatory response to stress of simulated flight and to physical exercise before and after propranolol blockade.

Stress can induce profound responses in the cardiovascular system. In such situations increased systemic blood pressure and flow have been observed (Groilman, 1929; Stead et al., 1945; Hickam, Cargill, and Golden, 1948; Stevenson, Duncan, and Wolff, 1949; Wolf et al., 1955). Much of our further knowledge of the responses to emotional stimuli on central and regional hamodynamics in man has been summarized by Brod (1963). In most investigations the experimental situations and environments cannot be considered representative of day-to-day stressful occurrences. For example, most often stimuli such as mental arith-