Presence of a substance P-like peptide in an acid extract of the intestinal bulb of the carp (Cyprinus carpio).
1. The effect of an acid extract of the carp intestinal bulb (ECI) on guinea-pig ileum longitudinal smooth muscle (GPLM) and carp intestinal bulb longitudinal smooth muscle (CIBLM) was examined. 2. ECI caused a concentration-dependent contraction of GPLM and CIBLM. This ECI-induced response was reduced by atropine to 30-40% of the control, indicating that part of the contracting activity of ECI is attributable to acetylcholine. The atropine-resistant contracting activity of ECI was not mediated by histamine, 5-hydroxytryptamine, ATP, ADP, angiotensin II, neurotensin, vasoactive intestinal peptide or an opioid peptide. 3. The active material mediating the atropine-resistant contracting activity is probably a peptide, because the contraction in response to ECI was abolished on incubation with pepsin or alpha-chymotrypsin. 4. [D-Pro2, D-Trp7,9]-substance P, [D-Pro4, D-Trp7,9]-substance P (4-11) decreased the atropine-resistant contracting activity of ECI as did desensitization induced by substance P. 5. On a Sephadex G 25 column, the active material was eluted as one peak. The active fractions were pooled and then applied to another Sephadex G25 column to compare the Ve/Vo value for the active material with those for peptides of known molecular weights. The molecular weight of the active material was estimated to be 1200-1700 (1410 +/- 70, n = 6). 6. The results indicate the presence of a substance P-like peptide in the carp intestinal bulb.
Kitazawa
T
T
Department of Veterinary Pharmacology, School of Veterinary Medicine and Animal Sciences, Kitasato University, Aomori, Japan.
Kondo
H
H
Temma
K
K
D000109:Acetylcholine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002347:Carps / Q000502:physiology*; D002850:Chromatography, Gel; D002918:Chymotrypsin / Q000494:pharmacology; D003530:Cyprinidae / Q000502:physiology*; D005260:Female; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D007422:Intestines / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009496:Neurotensin / Q000494:pharmacology; D010434:Pepsin A / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D013373:Substance P / Q000302:isolation & purification* / Q000494:pharmacology; D014020:Tissue Extracts / Q000032:analysis / Q000502:physiology*
D014020:Tissue Extracts; D000804:Angiotensin II; D012701:Serotonin; D013373:Substance P; D009496:Neurotensin; D006632:Histamine; D000255:Adenosine Triphosphate; D002918:Chymotrypsin; D010434:Pepsin A; D000109:Acetylcholine