| Autor: |
Häggblad, J., Eriksson, H., Hedlund, B., Heilbronn, E. |
| Zdroj: |
Naunyn-Schmiedeberg's Archives of Pharmacology; 1987, Vol. 336 Issue 4, p381-386, 6p |
| Abstrakt: |
Forskolin, a commonly used adenylate cyclase activator, was found to inhibit reversibly the carbachol-induced ion-translocating capacity of the nicotinic acetylcholine receptor (nAChR) on chick myotubes in a dose- (IC = 20 μM) and time-dependent manner. This effect was not correlated to increases in cellular cAMP. Forskolin, at a concentration (50 μM) that totally blocked the carbachol-induced Rb influx, caused no change in carbachol or α-bungarotoxin binding to chick myotube nAChR in situ. In contrast, in the presence of carbachol, forskolin inhibited (IC = 10 μM) the binding of H-phencyclidine, a putative nAChR ion-channel ligand, to Torpedo microsac nAChR. Inhibition of H-phencyclidine binding in the absence of carbachol was not complete. Membrane leakage studies on myotubes, measuring H-efflux from 2-deoxy- d(1-H)-glucose loaded cells and electrophysiological measurements of membrane properties supported the interpretation that forskolin induced decreases in plasma membrane permeability. In conclusion, forskolin blocks the carbachol-mediated increase in permeability of the nAChR channel by (1) binding to the ion-channel (open state) and (2) generally perturbing the plasma membrane function possibly by interfering with the protein-lipid interface. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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