![]()
|
|
||||||||
J. Biol. Chem., Vol. 259, Issue 15, 9520-9525, 08, 1984
M Ueda, FW Robinson, MM Smith and T Kono
Effects of divalent cations on the regulation of glucose transport and cAMP phosphodiesterase in isolated rat epididymal adipocytes were studied. EDTA (5 mM) moderately inhibited the binding of insulin to adipocytes in Krebs-Henseleit Hepes buffer. In the same buffer, A-23187 (an ionophore specific for divalent cations; 50 microM) plus EDTA (5 mM) almost completely blocked the insulin- or hydrogen peroxide- dependent stimulation of phosphodiesterase. This inhibition was not secondary to the loss of ATP. When cells that had been treated with A- 23187 plus EDTA were washed and then exposed to 1-10 mM of divalent cations, the cellular phosphodiesterase activity was elevated. Mn2+ was most stimulatory, Mg2+ was next, and Ca2+ was least effective. The stimulatory effects were enhanced by insulin. In the presence of insulin, Mn2+ at 10 mM was less stimulatory than that at 1 mM. In regular Krebs-Henseleit Hepes buffer, Mn2+ greatly stimulated phosphodiesterase if cells were first exposed to A-23187. The Mn2+- dependent stimulation was blocked by treatment of cells with 2,4- dinitrophenol. Results essentially parallel to those described above were also obtained when the rate of glucose transport was determined. The above results indicate that divalent cations mildly support the extracellular binding of insulin to its receptor, facilitate the physiological actions of insulin, and mimic the hormone actions, presumably by stimulating an intracellular enzyme.
This article has been cited by other articles:
![]() |
L. R. Legleiter, J. W. Spears, and K. E. Lloyd Influence of dietary manganese on performance, lipid metabolism, and carcass composition of growing and finishing steers J Anim Sci, October 1, 2005; 83(10): 2434 - 2439. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Gaudiot, C. Ribiere, A.-M. Jaubert, and Y. Giudicelli Endogenous nitric oxide is implicated in the regulation of lipolysis through antioxidant-related effect Am J Physiol Cell Physiol, November 1, 2000; 279(5): C1603 - C1610. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Dimon-Gadal, P. Gerbaud, G. Keryer, W. Anderson, D. Evain-Brion, and F. Raynaud In Vitro Effects of Oxygen-derived Free Radicals on Type I and Type II cAMP-Dependent Protein Kinases J. Biol. Chem., August 28, 1998; 273(35): 22833 - 22840. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |