title: Distribution and function of brain natriuretic peptide in the stomach and small intestine of the rat.
abstract: The distribution and function of brain natriuretic peptide (BNP) was studied in the rat stomach and jejunum. BNP-like immunoreactive nerves were found in the myenteric plexus, circular muscle, submucosa and in the crypt region of the jejunum. In the stomach, BNP-like immunoreactivity was found in the myenteric plexus, circular muscle, submucosa and at the base of the gastric glands. In the submucosa, BNP-like immunoreactivity was often associated with blood vessels. In segments of rat jejunum mounted in Ussing chambers, serosal exposure to rat BNP caused a concentration-dependent increase in short circuit current. A maximal effect of 18 +/- 4 microA/cm2 was observed with 1 microM BNP. The effect was quantitatively and qualitatively similar to that elicited by serosal exposure to equimolar atrial natriuretic peptide. The response to BNP was reduced by 88% in chloride free Kreb's buffer, by 83% in tissues pretreated with cinanserin, an antagonist of the 5-HT2 subtype of the 5-hydroxytryptamine receptor, and by 96% in tissues pretreated with tetrodotoxin, a blocker of axonal conduction. These results are consistent with a physiological role for BNP as a neuromodulator of gastrointestinal electrolyte transport.
authors.affiliation: Neuroscience Group, University of Calgary, Alberta, Canada.
authors.forename: K A
authors.initials: KA
authors.lastname: Sharkey
authors.forename: D G
authors.initials: DG
authors.lastname: Gall
authors.forename: W K
authors.initials: WK
authors.lastname: MacNaughton
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D004553:Electric Conductivity; D004573:Electrolytes / Q000378:metabolism; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D007150:Immunohistochemistry; D007583:Jejunum / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D020097:Natriuretic Peptide, Brain; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D013270:Stomach / Q000737:chemistry / Q000502:physiology
chemical_list: D004573:Electrolytes; D009419:Nerve Tissue Proteins; D020097:Natriuretic Peptide, Brain