Forskolin Blocks Carbachol-mediated Ion-permeability of Chick Myotube Nicotinic Receptors and Inhibits Binding of 3H-phencyclidine to Torpedo Microsac Nicotinic Receptors

Overview

Journal Naunyn Schmiedebergs Arch Pharmacol

Specialty Pharmacology

Date 1987 Oct 1

PMID 2448658

Citations 1

Authors

J Haggblad

H Eriksson

B Hedlund

E Heilbronn

Affiliations

Soon will be listed here.

Abstract

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- (IC50 = 20 microM) and time-dependent manner. This effect was not correlated to increases in cellular cAMP. Forskolin, at a concentration (50 microM) that totally blocked the carbachol-induced 86Rb influx, caused no change in carbachol or alpha-bungarotoxin binding to chick myotube nAChR in situ. In contrast, in the presence of carbachol, forskolin inhibited (IC50 = 10 microM) the binding of 3H-phencyclidine, a putative nAChR ion-channel ligand, to Torpedo microsac nAChR. Inhibition of 3H-phencyclidine binding in the absence of carbachol was not complete. Membrane leakage studies on myotubes, measuring 3H-efflux from 2-deoxy-D(1-3H)-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.

Citing Articles

Desensitization of the acetylcholine receptor of frog end-plates measured in a Vaseline-gap voltage clamp.

Cachelin A, Colquhoun D J Physiol. 1989; 415:159-88.

PMID: 2561785 PMC: 1189172. DOI: 10.1113/jphysiol.1989.sp017717.

Effects of forskolin and analogues on nicotinic receptor-mediated sodium flux, voltage-dependent calcium flux, and voltage-dependent rubidium efflux in pheochromocytoma PC12 cells.

Nishizawa Y, Seamon K, Daly J, Aronstam R Cell Mol Neurobiol. 1990; 10(3):351-68.

PMID: 1701359 PMC: 11567200. DOI: 10.1007/BF00711180.

References

NASTUK W, Su P, Doubilet P . Anticholinergic and membrane activities of amantadine in neuromuscular transmission. Nature. 1976; 264(5581):76-9. DOI: 10.1038/264076a0. View

Hedlund B, Arhem P, Lorentz M, Sydbom A . Non-muscarinic effects of scopolamine on N1E-115 neuroblastoma cells. Acta Physiol Scand. 1986; 127(1):127-32. DOI: 10.1111/j.1748-1716.1986.tb07884.x. View

Heidmann T, Oswald R, Changeux J . Multiple sites of action for noncompetitive blockers on acetylcholine receptor rich membrane fragments from torpedo marmorata. Biochemistry. 1983; 22(13):3112-27. DOI: 10.1021/bi00282a014. View

Warnick J, Maleque M, Bakry N, Eldefrawi A, Albuquerque E . Structure-activity relationships of amantadine. I. Interaction of the N-alkyl analogues with the ionic channels of the nicotinic acetylcholine receptor and electrically excitable membrane. Mol Pharmacol. 1982; 22(1):82-93. View

Albuquerque E, Deshpande S, Aracava Y, Alkondon M, Daly J . A possible involvement of cyclic AMP in the expression of desensitization of the nicotinic acetylcholine receptor. A study with forskolin and its analogs. FEBS Lett. 1986; 199(1):113-20. DOI: 10.1016/0014-5793(86)81235-2. View

Eldefrawi M, Eldefrawi A, Aronstam R, Maleque M, Warnick J, Albuquerque E . [3H]Phencyclidine: a probe for the ionic channel of the nicotinic receptor. Proc Natl Acad Sci U S A. 1980; 77(12):7458-62. PMC: 350523. DOI: 10.1073/pnas.77.12.7458. View

Oswald R . Effects of calcium on the binding of phencyclidine to acetylcholine receptor-rich membrane fragments from Torpedo californica electroplaque. J Neurochem. 1983; 41(4):1077-84. DOI: 10.1111/j.1471-4159.1983.tb09054.x. View

Schimerlik M, Quast U, RAFTERY M . Ligand-induced changes in membrane-bound acetylcholine receptor observed by ethidium fluorescence. 1. Equilibrium studies. Biochemistry. 1979; 18(10):1884-90. DOI: 10.1021/bi00577a006. View

LOWRY O, ROSEBROUGH N, FARR A, RANDALL R . Protein measurement with the Folin phenol reagent. J Biol Chem. 1951; 193(1):265-75. View

10.

Middleton P, Jaramillo F, Schuetze S . Forskolin increases the rate of acetylcholine receptor desensitization at rat soleus endplates. Proc Natl Acad Sci U S A. 1986; 83(13):4967-71. PMC: 323865. DOI: 10.1073/pnas.83.13.4967. View

11.

Whetton A, Needham L, Dodd N, Heyworth C, Houslay M . Forskolin and ethanol both perturb the structure of liver plasma membranes and activate adenylate cyclase activity. Biochem Pharmacol. 1983; 32(10):1601-8. DOI: 10.1016/0006-2952(83)90334-9. View

12.

Catterall W . Sodium transport by the acetylcholine receptor of cultured muscle cells. J Biol Chem. 1975; 250(5):1776-81. View

13.

Oswald R, Changeux J . Ultraviolet light-induced labeling by noncompetitive blockers of the acetylcholine receptor from Torpedo marmorata. Proc Natl Acad Sci U S A. 1981; 78(6):3925-9. PMC: 319686. DOI: 10.1073/pnas.78.6.3925. View

14.

Albuquerque E, Eldefrawi A, Eldefrawi M, Mansour N, Tsai M . Amantadine: neuromuscular blockade by suppression of ionic conductance of the acetylcholine receptor. Science. 1978; 199(4330):788-90. DOI: 10.1126/science.622570. View

15.

McHugh E, McGee Jr R . Direct anesthetic-like effects of forskolin on the nicotinic acetylcholine receptors of PC12 cells. J Biol Chem. 1986; 261(7):3103-6. View

16.

Albuquerque E, Tsai M, Aronstam R, Eldefrawi A, Eldefrawi M . Sites of action of phencyclidine. II. Interaction with the ionic channel of the nicotinic receptor. Mol Pharmacol. 1980; 18(2):167-78. View

17.

Manning A, Kinoshita K, Buschmans E, Coltart D, Hearse D . The genesis of arrhythmias during myocardial ischemia. Dissociation between changes in cyclic adenosine monophosphate and electrical instability in the rat. Circ Res. 1985; 57(5):668-75. DOI: 10.1161/01.res.57.5.668. View

18.

Haggblad J, Eriksson H, Heilbronn E . Oxotremorine acts as a partial nicotinic agonist on cultured chick myotubes. Acta Pharmacol Toxicol (Copenh). 1985; 57(5):317-21. DOI: 10.1111/j.1600-0773.1985.tb00051.x. View

19.

Walum E . Membrane lesions in cultured mouse neuroblastoma cells exposed to metal compounds. Toxicology. 1982; 25(1):67-74. DOI: 10.1016/0300-483x(82)90087-7. View

20.

Eldefrawi A, Miller E, Murphy D, Eldefrawi M . [3H]Phencyclidine interactions with the nicotinic acetylcholine receptor channel and its inhibition by psychotropic, antipsychotic, opiate, antidepressant, antibiotic, antiviral, and antiarrhythmic drugs. Mol Pharmacol. 1982; 22(1):72-81. View