Affordable Access

Interaction between carbachol and vasoactive intestinal peptide in cells of isolated colonic crypts.

Authors
  • Greenwald, L
  • Biagi, B A
Type
Published Article
Journal
The American journal of physiology
Publication Date
May 01, 1992
Volume
262
Issue
5 Pt 1
Identifiers
PMID: 1590403
Source
Medline
License
Unknown

Abstract

In a previous study [B. Biagi, Y.-Z. Wang, and H. J. Cooke, Am. J. Physiol. 258 (Gastrointest. Liver Physiol. 21): G223-G230, 1990], carbachol stimulated active chloride transport in rabbit distal colon, yet had no effect on the basolateral membrane potential (Vbl) of cells from isolated crypts from the same tissue. In the present study, crypt cells were first depolarized with vasoactive intestinal peptide (VIP; 1 x 10(-9) M) (control Vbl = -62 mV; VIP Vbl = -48 mV) and then exposed to carbachol in the presence of VIP. The VIP-induced depolarization of Vbl was completely reversed by carbachol (0.1 mM; repolarization to -65 mV). Similar repolarization was seen by applying carbachol to crypt cells depolarized by 10 mM aminophylline. Intracellular K+ activity (aiK), measured with K(+)-selective microelectrodes, was 64.3 mM (concn = 85 mM), yielding a K+ equilibrium potential (EK+) of -76 mV. Neither carbachol nor VIP application caused significant changes in aiK. These results demonstrate the presence of cholinergic receptors on colonic crypt cells. The magnitude of the carbachol effect on Vbl is greater when Vbl is depolarized relative to EK+. The results are consistent with the hypothesis that carbachol acts by increasing basolateral K+ conductance, driving the cell toward the EK+.

Report this publication

Statistics

Seen <100 times