TY - JOUR
T1 - Effects of trout endothelin on the motility of gastrointestinal smooth muscle from the trout and rat
AU - Wang, Yuqi
AU - Jensen, Jorgen
AU - Abel, Peter W.
AU - Fournier, Alain
AU - Holmgren, Susanne
AU - Conlon, J. Michael
PY - 2001
Y1 - 2001
N2 - Trout endothelin (ET), previously isolated from the kidney of the rainbow trout Oncorhynchus mykiss, contains four amino acid substitutions at residues 4-7 compared with rat ET-1. Trout ET produced sustained and concentration-dependent contractions of strips of longitudinal smooth muscle from trout stomach (pD2 = 7.52 ± 0.06) and proximal small intestine (pD2 = 7.80 ± 0.10) and from rat fundus (pD2 = 7.78 ± 0.14). Rat ET-1 was equipotent with trout ET for contraction of rat fundus and 2- to 3-fold more potent for contraction of trout gastrointestinal tissues. In contrast, rat ET-1 was 10- to 20-fold more potent than trout ET in constricting isolated rings of vascular tissue from trout efferent branchial artery and cardinal vein and from rat aorta (Y. Wang et al., 1999, Am. J. Physiol. 277, R1605-R1611). It is known that the contractile effects of ET-1 on rat fundus are mediated through the ETB receptor and effects on the rat aorta are mediated through the ETA receptor. We propose, therefore, that trout gastrointestinal tissues express an ETB-type receptor that differentiates poorly between trout ET and rat ET-1, whereas trout vascular tissues express an ETA-type receptor that is preferentially activated by rat ET-1. The rat ET-1-induced contractions of the trout gastrointestinal tissues are in part indirect, involving a serotoninergic neuronal pathway in the intestine and a noncholinergic, nonserotoninergic pathway in the stomach.
AB - Trout endothelin (ET), previously isolated from the kidney of the rainbow trout Oncorhynchus mykiss, contains four amino acid substitutions at residues 4-7 compared with rat ET-1. Trout ET produced sustained and concentration-dependent contractions of strips of longitudinal smooth muscle from trout stomach (pD2 = 7.52 ± 0.06) and proximal small intestine (pD2 = 7.80 ± 0.10) and from rat fundus (pD2 = 7.78 ± 0.14). Rat ET-1 was equipotent with trout ET for contraction of rat fundus and 2- to 3-fold more potent for contraction of trout gastrointestinal tissues. In contrast, rat ET-1 was 10- to 20-fold more potent than trout ET in constricting isolated rings of vascular tissue from trout efferent branchial artery and cardinal vein and from rat aorta (Y. Wang et al., 1999, Am. J. Physiol. 277, R1605-R1611). It is known that the contractile effects of ET-1 on rat fundus are mediated through the ETB receptor and effects on the rat aorta are mediated through the ETA receptor. We propose, therefore, that trout gastrointestinal tissues express an ETB-type receptor that differentiates poorly between trout ET and rat ET-1, whereas trout vascular tissues express an ETA-type receptor that is preferentially activated by rat ET-1. The rat ET-1-induced contractions of the trout gastrointestinal tissues are in part indirect, involving a serotoninergic neuronal pathway in the intestine and a noncholinergic, nonserotoninergic pathway in the stomach.
KW - Endothelin
KW - Gastrointestinal vascular smooth muscle
KW - Trout
UR - http://www.scopus.com/inward/record.url?scp=0034920106&partnerID=8YFLogxK
U2 - 10.1006/gcen.2001.7658
DO - 10.1006/gcen.2001.7658
M3 - Article
C2 - 11482936
AN - SCOPUS:0034920106
SN - 0016-6480
VL - 123
SP - 156
EP - 162
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 2
ER -