Journal article

Publication year: 2006

Pages: 229-233

Journal: European Journal of Pharmacology

Volume number: 530

Issue number: 3

ISSN: 0014-2999

eISSN: 1879-0712

DOI Link: https://doi.org/10.1016/j.ejphar.2005.11.055

Publisher: Elsevier

Abstract: 

Cholinergically induced intestinal anion secretion is generally believed to be caused by stimulation of epithelial muscarinic M-3 receptors, whereas muscarinic M-1 receptors are thought to be localized primarily on enteric neurons. In order to test this assumption, carbachol-stimulated Cl- secretion across distal colon, measured as increase in short-circuit current (I-sc), was compared between M-1-knockout (M1R-KO) and M-3- knockout (M3R-KO) mice. Surprisingly, the maximal increase in,, evoked by carbachol was more than twice as large in M3R-KO compared to MIR-KO mice. This difference was not due to a reduced secretory capacity of the epithelium from M3R-KO animals, as forskolin stimulated a similar maximal I-sc in both types of animals. The neurotoxin tetrodotoxin diminished, but did not abolish the secretory response evoked by carbachol in M3R-KO distal colon, suggesting the existence of epithelial muscarinic receptors other than the type M-3. Furthermore, in muscarinic receptor wild-type animals, the muscarinic M-1 receptor antagonist pirenzepine inhibited the carbachol-stimulated I-sc by more than 70% suggesting the presence of epithelial muscarinic M-1 receptors; a conclusion, which was confirmed by the identification of mRNA for muscarinic M-1 receptors in isolated crypts from wild-type colon. Consequently, epithelial muscarinic receptors from the type M-1 contribute to cholinergically induced ion secretion in mouse colon.

Harvard Citation style: Haberberger, R., Schultheiss, G. and Diener, M. (2006) Epithelial muscarinic M1 receptors contribute to carbachol-induced ion secretion in mouse colon, European Journal of Pharmacology, 530(3), pp. 229-233. https://doi.org/10.1016/j.ejphar.2005.11.055

APA Citation style: Haberberger, R., Schultheiss, G., & Diener, M. (2006). Epithelial muscarinic M1 receptors contribute to carbachol-induced ion secretion in mouse colon. European Journal of Pharmacology. 530(3), 229-233. https://doi.org/10.1016/j.ejphar.2005.11.055