COMPARISON OF CIRCULATORY AND METABOLIC EFFECTS OF ISOPROTERENOL EPINEPHRINE AND METHOXAMINE IN NORMAL AND ASTHMATIC SUBJECTS

The circulatory responses of eleven asthmatic patients and six normal subjects were studied during infusion of isoproterenol, epinephrine and methoxamine. Blood pressure, heart rate, cardiac index, stroke volume index and peripheral resistance index were measured. The finding of increased myocardial chronotropic and inotropic stimulation with isoproterenol in asthmatic patients does not support the view that circulatory beta-adrenergic blockade is present. Responses of asthmatic patients and normal subjects to epinephrine infusion were sharply divergent. The difference observed between the two groups is not readily explained in terms of alpha- and beta-adrenergic sensitivity. The metabolic responses of the four normal subjects and the four asthmatic patients studied here were not significantly different. © 1968.