![]() |
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
GASTROINTESTINAL, HEPATIC, PULMONARY, AND RENAL
Departments of Medicine (T.S., C.F., M.C.M.) and Urology (T.S., S.K.), University of Essen, Essen, Germany; and Department of Pharmacology and Pharmacotherapy (M.C.M.), University of Amsterdam, Amsterdam, The Netherlands
The present study was designed to reexamine the muscarinic acetylcholine receptor subtype mediating carbachol-induced contraction of human urinary bladder and to investigate the underlying signal transduction. Based upon the nonselective tolterodine, the highly M2-selective (R)-4-{2-[3-(4-methoxy-benzoylamino)-benzyl]-piperidin-1-ylmethyl}piperidine-1-carboxylic acid amide (Ro-320-6206), and the highly M3-selective darifenacin and 3-(1-carbamoyl-1,1-diphenylmethyl)-1-(4-methoxyphenylethyl)pyrrolidine (APP), contraction occurs via M3 receptors. The phospholipase C inhibitor 1-(6-[([17
]-3-methoxyestra-1,3,5[10]-trien-17-yl)amino]hexyl)-1H-pyrrole-2,5-dione (U 73,122) (1-10 µM) did not significantly affect carbachol-stimulated bladder contraction. The phospholipase D inhibitor butan-1-ol relative to its negative control butan-2-ol (0.3% each) caused small but detectable inhibition of carbachol-induced bladder contraction. The Ca2+ entry blocker nifedipine (10-100 nM) strongly inhibited carbachol-induced bladder contraction. In contrast, 1-[
-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole HCl (SK&F 96,365) (1-10 µM), an inhibitor of store-operated Ca2+ channels, caused little inhibition. The protein kinase C inhibitor bisindolylmaleimide I (1-10 µM) did not significantly affected carbachol-induced bladder contraction. In contrast, trans-4-[(1R)-1-aminoethyl]-N-4-pyridinylcyclohexanecarboxamide (Y 27,632) (1-10 µM), an inhibitor of rho-associated kinases, concentration dependently and effectively attenuated the carbachol responses. We conclude that carbachol-induced contraction of human urinary bladder via M3 receptors largely depends on Ca2+ entry through nifedipine-sensitive channels and activation of a rho kinase, whereas phospholipase D and store-operated Ca2+ channels contribute only in a minor way. Surprisingly, phospholipase C or protein kinase C do not seem to be involved to a relevant extent.
Address correspondence to: Prof. Martin C. Michel, Academisch Medisch Centrum, Afd. Farmacologie en Farmacotherapie, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands. E-mail: m.c.michel{at}amc.uva.nl
This article has been cited by other articles:
![]() |
A. Morelli, R. Squecco, P. Failli, S. Filippi, L. Vignozzi, A. K. Chavalmane, B. Fibbi, R. Mancina, G. Luciani, M. Gacci, et al. The vitamin D receptor agonist elocalcitol upregulates L-type calcium channel activity in human and rat bladder Am J Physiol Cell Physiol, May 1, 2008; 294(5): C1206 - C1214. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. P. Frazier, A. S. Braverman, S. L. M. Peters, M. C. Michel, and M. R. Ruggieri Sr. Does Phospholipase C Mediate Muscarinic Receptor-Induced Rat Urinary Bladder Contraction? J. Pharmacol. Exp. Ther., September 1, 2007; 322(3): 998 - 1002. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. S. Braverman, A. S. Tibb, and M. R. Ruggieri Sr M2 and M3 Muscarinic Receptor Activation of Urinary Bladder Contractile Signal Transduction. I. Normal Rat Bladder J. Pharmacol. Exp. Ther., February 1, 2006; 316(2): 869 - 874. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. P. Frazier, M.-J. Mathy, S. L. M. Peters, and M. C. Michel Does Cyclic AMP Mediate Rat Urinary Bladder Relaxation by Isoproterenol? J. Pharmacol. Exp. Ther., April 1, 2005; 313(1): 260 - 267. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Ding and P. A. Murray Regulation of pulmonary venous tone in response to muscarinic receptor activation Am J Physiol Lung Cell Mol Physiol, January 1, 2005; 288(1): L131 - L140. [Abstract] [Full Text] [PDF] |
||||