Calorigenic Response of Warm- and Coldadapted Rabbits to Intravenous Infusion of Epinephrine and Norepinephrine

摘要

Measurements were made on 16 New Zealand and 8 Dutch breed rabbits to determine the effect of cold acclimation on the calorigenic responsiveness to epinephrine and norepinephrine. Oxygen consumption, colonic temperature, respiratory rate and blood glucose measurements were made before, during and after intravenous infusion of epinephrine (3micrograms/kg/min) and norepinephrine (30micrograms/kg/min). Warm-adapted rabbits (27 = 1C) showed less increase in colonic temperature and oxygen consumption after infusion of epinephrine and norepinephrine than did cold-adapted rabbits (5 = 1C). Blood glucose concentration increased equally in both groups after infusion of epinephrine and norepinephrine. Respiratory rate decreased the same in warm- and cold-adapted animals during infusion of norepinephrine and increased after infusion was stopped. In cold-adapted groups I and III norepinephrine infusion increased oxygen consumption 3 and 13 times greater than that of warm-adapted groups I and III. In cold-adapted group II oxygen consumption did not increase notably above that of warm-adapted group II after infusion of norepinephrine. Epinephrine infusion induced an increased oxygen consumption in cold-adapted groups I and II tow and five times greater than that of warm-adapted groups I and II. Cold-adapted group III showed no marked increase in oxygen consumption above that of warm-adapted group III after infusion of epinephrine. (Author)