Characterisation of the endogenous intestinal peptide that stimulates the
rectal gland of scyliorhinus canicula..
Gary, W., Anderson, J. Michael Conlon* and Neil Hazon.
Department of Biology and Preclinical Medicine, Gatty Marine Laboratory,
University of St. Andrews, KY16 8LB; and * Regulatory Peptide Centre,
Department of Biomedical Sciences, Creighton University, Omaha Nebraska
68178.
APStracts 2:0006R, 1995.
It has been postulated that gut peptides play a major role in the regulation
of rectal gland secretion in elasmobranchs. An isolated perfused rectal gland
preparation was developed for Scyliorhinus canicula, that responded to
Dibutyrl 3'5' cyclic monophosphate plus Isobutyl-methylxanthine increasing
chloride clearance rates 3 fold over basal levels. Activity was stimulated by
an endogenous peptide, isolated in pure form by reverse-phase HPLC, from the
intestine of S. canicula . The primary structure was established as: Ser-Pro
-Ser-Asn-Ser-Lys-Cys-Pro-Asp-Gly-Pro-Asp-Cys-Phe-Val-Gly-Leu-Met-NH2. This is
a sequence identical to that of the tachykinin scyliorhinin II. Perfusion of
synthetic scyliorhinin II increased secretion rate in the rectal gland of S.
canicula in a dose dependant manner, with a maximal response at 10-6M,
whereas vasoactive intestinal peptide, a stimulator in the spiny dogfish,
Squalus acanthias had no effect. We propose that scyliorhinin II is the
uncharacterized peptide rectin, previously identified from the intestine of
S. canicula .
Received 3 October 1994; accepted in final form 3 January 1995.
APS Manuscript Number R571-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative Comp.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 25 February 1995.