NOREPINEPHRINE-INDUCED DEPOLARIZATION OF BROWN FAT CELLS
- 1 September 1969
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 64 (1), 113-120
- https://doi.org/10.1073/pnas.64.1.113
Abstract
Intracellular potentials of brown fat cells in lightly anesthetized cold-acclimated rats were measured in vivo. The effects of adrenergic agonists and antagonists on these potentials were examined in an attempt to relate the electrical activity of the cells to the adrenergic-induced stimulation of brown fat thermogenesis.Norepinephrine, the physiological mediator of brown fat heat production, significantly depolarized the membrane of these cells in vivo. This was effected either upon norepinephrine administration (3-100 mug/kg body wt) or excitation of the transsected nerve trunk to the interscapular fat pad and appreciably inhibited (55%) by doses of propranolol (1 mg/kg) sufficient to abolish the temperature increase of the tissue. Since theophylline (325 mum/kg) did not depolarize the cells, although it stimulated thermogenesis in the tissue, the depolarizing effect of norepinephrine is interpreted as being at least partially associated with biochemical events terminating in the activation of adenylate cyclase. However, the norepinephrine-induced electrical changes and the ensuing increase in brown fat thermogenesis appear to be causally independent and experimentally separable. On the other hand, our data do not preclude the speculation that the membrane phenomenon, if accompanied by increased Na(+), may serve partially to regulate the metabolic rate of brown fat during long-term physiological stimulation (e.g., cold stress) by increasing the rate of ATP utilization via the Na(+)/K(+) pump.Keywords
This publication has 10 references indexed in Scilit:
- Brown fat and thermogenesis.Physiological Reviews, 1969
- Membrane Potential of Brown Adipose TissueThe Journal of general physiology, 1968
- Effect of norepinephrine and uncoupling agents on brown adipose tissueCanadian Journal of Physiology and Pharmacology, 1968
- The effect of propranalol on the calorigenic response in brown adipose tissue of new‐born rabbits to catecholamines, glucagon, corticotrophin and cold exposureThe Journal of Physiology, 1966
- Sympathetic nervous control of brown adipose tissue and heat production in the new‐born rabbit.The Journal of Physiology, 1965
- CYTOLOGICAL RESPONSES OF BROWN FAT TISSUE IN COLD-EXPOSED RATSThe Journal of cell biology, 1964
- Brown Adipose Tissue and Thermoregulatory Heat Production in the RatNature, 1964
- Brown adipose tissue and the response of new‐born rabbits to coldThe Journal of Physiology, 1964
- Brown Fat: Thermogenic Effect during Arousal from Hibernation in the BatScience, 1963
- Brown Fat: Thermogenic Effector of Arousal in HibernatorsScience, 1963