Dendroaspis natriuretic peptide system and its paracrine function in rat colon.
Dendroaspis natriuretic peptide (DNP), a 38-amino-acid peptide, was isolated from the venom of Green Mamba. It has structural and functional similarities to other members of the natriuretic peptide family. The purpose of this study was to determine whether DNP system is present in the rat colon and to define its biological functions. The serial dilution curve of extracts of colonic tissues was parallel to the standard curve of DNP and a major peak of molecular profile by HPLC was synthetic DNP. The concentration of DNP was 0.5 +/- 0.04 ng/g of colonic tissues. DNP as well as atrial natriuretic peptide and C-type natriuretic peptide caused dose-dependent increases in cGMP production in the purified membrane of colonic tissues. Three types of natriuretic peptide receptor mRNAs were detected using semi-quantitative RT-PCR. Functionally, synthetic DNP inhibited the spontaneous contraction of rat colonic circular muscle in a concentration-dependent manner. The potency appeared to be at least 10 times greater than that of CNP. Furthermore, DNP inhibited carbachol-induced muscle contraction, suggesting that it also can modulate the nerve regulation of colonic motility. This study demonstrates the presence of DNP system in rat colon and its function as a local regulator of colonic motility.
Kim
Jong Hun
JH
Department of General Surgery, Chonbuk National University Medical School, Jeonju 560-181, South Korea.
Yang
Sung Hoon
SH
Yu
Mo Young
MY
Lee
Hye Kyung
HK
Kim
So Young
SY
Kim
Suhn Hee
SH
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002316:Cardiotonic Agents / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D004546:Elapid Venoms / Q000737:chemistry / Q000493:pharmacokinetics*; D006162:Guanylate Cyclase / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D020098:Natriuretic Peptide, C-Type / Q000235:genetics; D010455:Peptides / Q000737:chemistry / Q000493:pharmacokinetics*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D017461:Receptors, Atrial Natriuretic Factor / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000099242:Atrial Natriuretic Factor Receptor B
D002217:Carbachol; D002316:Cardiotonic Agents; D006152:Cyclic GMP; D004546:Elapid Venoms; D006162:Guanylate Cyclase; D036341:Intercellular Signaling Peptides and Proteins; D020098:Natriuretic Peptide, C-Type; D010455:Peptides; D012333:RNA, Messenger; D017461:Receptors, Atrial Natriuretic Factor; D000099242:Atrial Natriuretic Factor Receptor B; C075597:Dendroaspis natriuretic peptide; C091715:atrial natriuretic factor receptor A