Cholinergic antagonism of beta-adrenergic stimulated action potentials and adenylate cyclase activity in rabbit ventricular cardiomyocytes - PubMed (original) (raw)
Cholinergic antagonism of beta-adrenergic stimulated action potentials and adenylate cyclase activity in rabbit ventricular cardiomyocytes
J M Watson et al. Eur J Pharmacol. 1988.
Abstract
The cholinergic antagonism of beta-adrenergic stimulation was examined by measuring adenylate cyclase activity and calcium-mediated action potentials in isolated ventricular cardiomyocytes of adult rabbits. The beta-adrenoceptor agonist isoproterenol and the direct adenylate cyclase activator forskolin increased adenylate cyclase activity in homogenates of the myocytes. The cholinergic agonist carbachol (10 nM-100 microM) inhibited in a concentration dependent manner basal, isoproterenol-stimulated and forskolin-stimulated adenylate cyclase activity. The carbachol effect on basal adenylate cyclase activity was antagonized by atropine (10 microM). In parallel experiments using intact cardiomyocytes, calcium action potentials were elicited by intracellular depolarizing current pulses in partially depolarized preparations. These action potentials were prolonged by isoproterenol, forskolin and dibutyryl cyclic AMP. Acetylcholine reversibly inhibited the prolongation of the action potential induced by isoproterenol and forskolin but not dibutyryl cyclic AMP. These results suggest that cholinergic agonists modulate the increase in the calcium current elicited by isoproterenol and forskolin in isolated ventricular cardiomyocytes by inhibiting adenylate cyclase activity.
Similar articles
- Transregulation of adenylyl-cyclase-coupled inhibitory receptors in heart failure enhances anti-adrenergic effects on adult rat cardiomyocytes.
Borst MM, Szalai P, Herzog N, Kübler W, Strasser RH. Borst MM, et al. Cardiovasc Res. 1999 Oct;44(1):113-20. doi: 10.1016/s0008-6363(99)00197-2. Cardiovasc Res. 1999. PMID: 10615395 - Parasympathetic effects on electrophysiologic properties of cardiac ventricular tissue.
Rardon DP, Bailey JC. Rardon DP, et al. J Am Coll Cardiol. 1983 Dec;2(6):1200-9. doi: 10.1016/s0735-1097(83)80351-9. J Am Coll Cardiol. 1983. PMID: 6355243 Review.
Cited by
- Evidence for cocaine and methylecgonidine stimulation of M(2) muscarinic receptors in cultured human embryonic lung cells.
Yang Y, Ke Q, Cai J, Xiao YF, Morgan JP. Yang Y, et al. Br J Pharmacol. 2001 Jan;132(2):451-60. doi: 10.1038/sj.bjp.0703819. Br J Pharmacol. 2001. PMID: 11159694 Free PMC article. - Effects of gestational age and cortisol treatment on ovine fetal heart function in a novel biventricular Langendorff preparation.
Fletcher AJ, Forhead AJ, Fowden AL, Ford WR, Nathanielsz PW, Giussani DA. Fletcher AJ, et al. J Physiol. 2005 Jan 15;562(Pt 2):493-505. doi: 10.1113/jphysiol.2004.074161. Epub 2004 Oct 28. J Physiol. 2005. PMID: 15513943 Free PMC article.