Involvement of cyclic GMP in nitric-oxide-induced gastric relaxation - Comparison of the actions of cyclic GMP and cyclic AMP
- Authors
- Sim, SS; Kim, YC; Shim, HS; Choi, JC; Min, DS; Rhie, DJ; Yoon, SH; Hahn, SJ; Kim, MS; Jo, YH
- Issue Date
- Jan-2001
- Publisher
- TAYLOR & FRANCIS AS
- Keywords
- cyclic adenosine monophosphate; cyclic guanosine monophosphate; phospholipase C; smooth muscle contraction; trimethoxybenzoate-8; verapamil
- Citation
- SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY, v.36, no.1, pp 16 - 22
- Pages
- 7
- Journal Title
- SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY
- Volume
- 36
- Number
- 1
- Start Page
- 16
- End Page
- 22
- URI
- https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/25249
- DOI
- 10.1080/00365520150218011
- ISSN
- 0036-5521
- Abstract
- Background: Smooth muscle relaxation induced by various agents that increase the cellular levels of cyclic nucleotides (cAMP and cGMP) is accompanied by a decrease in intracellular Ca2+ concentration However, little is known about the differences between the inhibitory effects of cAMP and cGMP on the contraction of smooth muscle. Objective: To compare the effects and underlying mechanisms of cAMP and cGMP on the inhibition of gastric smooth muscle contraction, cyclic nucleotide promoting agents, as well as cell membrane permeable cyclic nucleotides were used. Methods: Isometric contraction was measured from circular muscle strips prepared from the fundus of cat stomach in a cylinder-shaped chamber filled with Krebs-Ringer solution (pH 7.4, temperature 36 degreesC) bubbled with. 5% CO2 in O-2. The level of inositol phosphates (IPs) was measured. Results: Forskolin and sodium nitroprusside significantly inhibited acetylcholine (ACh)-induced gastric smooth muscle contraction and increased the cellular levels of cAMP and cGMP, respectively. Direct application of 8-Br-cAMP and 8-Br-cGMP also significantly inhibited ACh-induced contraction. Both verapamil and TMB-8 inhibited ACh-induced contraction. The combined inhibitory effect of venpamil and TMB-8 was significantly greater than the effect of either one, separately. Forskolin or sodium nitroprusside similarly augmented the effect of verapamil. However, the inhibitory effect of TMB-8 was augmented only by 8-Br-cGMP or sodium nitroprusside but not by 8-Br-cAMP or forskolin. Forskolin and 8-Br-cAMP significantly inhibited the formation of inositol phosphates stimulated by ACh. Conclusions: cAMP inhibits the contraction mechanism associated with intracellular Ca2+ mobilization as well as extracellular Ca2+ influx, while cGMP inhibits contraction by inhibiting the mechanism associated with extracellular Ca2+ influx.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - College of Pharmacy > School of Pharmacy > 1. Journal Articles
![qrcode](https://api.qrserver.com/v1/create-qr-code/?size=55x55&data=https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/25249)
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.