ADENYL CYCLASE AND HORMONE ACTION, I. EFFECTS OF ADRENOCORTICOTROPIC HORMONE, GLUCAGON, AND EPINEPHRINE ON THE PLASMA MEMBRANE OF RAT FAT CELLS
- 1 June 1969
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 63 (2), 350-356
- https://doi.org/10.1073/pnas.63.2.350
Abstract
A large number of hormones, of diverse molecular structure, evoke characteristic responses in target cells via the intermediary 3',5'-AMP, the specificity of hormone action upon cell type being achieved by selective stimulation of adenyl cyclase. In the fat cells of rat adipose tissue, adenyl cyclase is stimulated by a number of hormones of disparate molecular structure, posing the question whether this cell type posesses multiple cyclase systems with distinctive specificities for individual hormones, or a single cyclase with broad specificity to a variety of hormones. Studies of the stimulatory effects of adenocorticotropin, glucagon, and epinephrine upon the adenyl cyclase of the rat fat cell "ghosts" (plasma membrane sacs) have shown that distinctive selectivity sites for each of these hormones can be differentiated. The beta-adrenergic blocking agent Kö 592 abolished the stimulatory effect of epinephrine without influencing adenocorticotropin or glucagon; Ca was required for adenocorticotropin action, but not for glucagon or epinephrine. Dose-response curves show that the affinity of hormones to the cyclase system was in the order: glucagon > adenocorticotropin >> epinephrine; the magnitude of cyclase activation by maximal doses of hormones had a reversed order. Combinations of maximal doses of hormones failed to produce additive stimulation. The results show that in the membrane of the fat cell a single catalytic unit of adenyl cyclase is coupled to distinctive selectivity sites for three lipolytic hormones.Keywords
This publication has 20 references indexed in Scilit:
- Histone Phosphorylation: Stimulation by Adenosine 3′,5′-MonophosphateScience, 1968
- The enhancement of phosphoryl transfer by adenosine 3′,5′-monophosphate in the presence of a membranous fraction from canine kidneyBiochimica et Biophysica Acta (BBA) - General Subjects, 1968
- Method for measuring hormonal effects on conversion of adenosine triphosphate to adenosine 3′, 5′-monophosphate by isolated lipocytesMetabolism, 1968
- Evidence for separate epinephrine and glucagon responsive adenyl cyclase systems in rat liverBiochemical and Biophysical Research Communications, 1968
- Cyclic AMPAnnual Review of Biochemistry, 1968
- The effect of catecholamines on the adenyl cyclase of frog and tadpole hemolysatesBiochemical and Biophysical Research Communications, 1968
- Activation of adenyl cyclase in thyroid homogenates by thyroid-stimulating hormoneBiochemical and Biophysical Research Communications, 1967
- Effects of electrolytes on epinephrine stimulated lipolysis in adipose tissue in vitroBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1967
- Acth stimulation of adenyl cyclase in adrenal homogenatesBiochemical and Biophysical Research Communications, 1967
- The effect of epinephrine and other agents on adenyl cyclase in the cell membrane of avian erythrocytesBiochimica et Biophysica Acta (BBA) - General Subjects, 1966