How Dendroaspis Natriuretic Peptide Regulates Gastric Motility

Main Category: GastroIntestinal / Gastroenterology
Also Included In: Biology / Biochemistry
Article Date: 26 Sep 2008 - 6:00 PDT

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Kim et al proved the presence of DNP-like immunore activity in the rat colon, and that the DNP-like molecule may control colonic motility as a local regulator. Up to now, there is little research exploring the relationship between DNP and gastric motility. In the author's previous study, they demonstrated that DNP inhibited gastric motility. However, the mechanism remains unclear.

A research article published on September 21, 2008 in the World Journal of Gastroenterology addresses this. The research team led by Prof. Guo from Centralab of the first Affiliated Hospital of Dalian Medical University used the patch-clamp technique, a pharmacologic approach and radioimmunoassays to systematically investigate if the cGMP/cGMP-dependent protein kinase (PKG) signaling pathway may participate in DNP-induced relaxation of gastric circular smooth muscle.

Their results showed that DNP markedly enhanced cGMP levels in gastric antral smooth muscle tissue and in the perfusion medium. DNP induced relaxation in gastric antral circular smooth muscle, which was inhibited by KT5823, a cGMP-dependent PKG inhibitor. DNP increased IK(Ca). This effect was almost completely blocked by KT5823, and partially blocked by LY83583, an inhibitor of guanylate cyclase to change the production of cGMP. DNP also increased spontaneous transient outward currents (STOCs). The effect of DNP on STOCs was abolished in presence by KT5823, but not affected by KT-5720, a PKA-specific inhibitor. It is concluded that DNP activates IK(Ca) and relaxes guinea-pig gastric antral circular smooth muscle via the cGMP/PKG-dependent singling axis, instead of cAMP/PKA pathway.

This work succeeded in better understanding the mechanism how DNP regulates gastric motility. It showed for the fist time that DNP activates IK(Ca) and relaxes guinea-pig gastric antral circular smooth muscle via the cGMP/PKG-dependent singling axis instead of cAMP/PKA pathway.

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Reference: Cai CY, Cai ZX, Gu XY, Shan LJ, Wang YX, Yin XZ, Qi QH, Guo HS. Dendroaspis natriuretic peptide relaxes gastric antral circular smooth muscle of guinea-pig through the cGMP/cGMP dependent protein kinase pathway. World J Gastroenterol 2008; 14(35): 5461-5466 http://www.wjgnet.com/1007-9327/14/5461.asp

Correspondence to: Hui-Shu Guo, Professor, Centralab, the first Affiliated Hospital of Dalian Medical Universty and Zhongshan Affiliated Hospital of Dalian University, Dalian 116011, Liaoning Province, China.

About World Journal of Gastroenterology

World Journal of Gastroenterology (WJG), a leading international journal in gastroenterology and hepatology, has established a reputation for publishing first class research on esophageal cancer, gastric cancer, liver cancer, viral hepatitis, colorectal cancer, and H pylori infection and provides a forum for both clinicians and scientists. WJG has been indexed and abstracted in Current Contents/Clinical Medicine, Science Citation Index Expanded (also known as SciSearch) and Journal Citation Reports/Science Edition, Index Medicus, MEDLINE and PubMed, Chemical Abstracts, EMBASE/Excerpta Medica, Abstracts Journals, Nature Clinical Practice Gastroenterology and Hepatology, CAB Abstracts and Global Health. ISI JCR 2003-2000 IF: 3.318, 2.532, 1.445 and 0.993. WJG is a weekly journal published by WJG Press. The publication dates are the 7th, 14th, 21st, and 28th day of every month. WJG is supported by The National Natural Science Foundation of China, No. 30224801 and No. 30424812, and was founded with the name of China National Journal of New Gastroenterology on October 1, 1995, and renamed WJG on January 25, 1998.

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Source: Lin Tian
World Journal of Gastroenterology

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