Pharmacologically Induced Resistance to Heat Shock

OBSERVATIONS on the protective action of three tranquilizing drugs—the rauwolfoids reserpine and reserpine-free mother liquor, and chlorpromazine—against death from exposure to a standardized experimental acute thermal stressor (Burger and Lorenz, 1960a) led to observations suggesting that a reduction in reactivity of the sympathetic nervous system is important (Burger and Lorenz, 1960b). Since heart rate reflects (however imperfectly) the activity of the sympathetic system, a series of experiments was undertaken attempting to relate heart rates to treatment with two of these drugs and to conditions of heat shock. MATERIALS AND METHODS For the experiments an electrocardiotachometer was constructed: Each lead was a flexible shielded cable (grid-lead wire) terminated at one end with a phono pin plug. At the other end the active lead was terminated with two 2-inch safety pins, and the indifferent lead with one. The leads were connected to a switch box with 48 input positions; the …