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Endothelin receptors mediating vasoconstriction in rat pressurized small arteries.
Can J Physiol Pharmacol. 1996 Aug; 74(8):934-9.CJ

Abstract

The effects of endothelin-1 (ET-1), a nonselective ETA and ETB receptor agonist, and sarafotoxin S6c, a selective ETB agonist, were investigated in the presence and absence of BQ123 and BQ788, ETA- and ETB-selective antagonists, respectively, in rat mesenteric small arteries, using a perfusion pressurized arteriograph in which segments of vessels were cannulated and exposed to constant pressure and flow. ET-1 (10(-13)-10(-7) M) induced vasoconstriction in both intact and endothelium-denuded arteries in a concentration-dependent manner. BQ123 (10(-7) and 10(-6) M) inhibited the effect of ET-1, displacing the concentration-response curve to the right in a concentration-dependent manner. The effect of ET-1 was not significantly affected by BQ788 (10(-7) and 10(-6) M), a selective antagonist of ETB receptors. Sarafotoxin S6c (10(-11)-10(-7) M) also induced a slight concentration-dependent vasoconstriction. The effect of sarafotoxin S6c (10(-8) M) was inhibited by the ETB-selective antagonist BQ788 (10(-7) M), but was not significantly changed by BQ123 (10(-7) M). Vasoconstriction induced by sarafotoxin S6c (10(-8) M) in a single bolus concentration was significantly greater than the contraction induced by the same concentration as part of a cumulative concentration-response curve, indicating desensitization or downregulation of ETB receptors during the latter. Repeated application of single concentrations of sarafotoxin S6c (10(-8) M) caused progressively smaller contraction of arteries. These results show the existence of both ETA and ETB vasoconstrictor receptors located on smooth muscle of small arteries. They also show that ETB receptors induce a smaller constrictor effect, and rapidly undergo desensitization after sustained or repeated activation.

Authors+Show Affiliations

MRC Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montréal, University of Montréal, QC, Canada.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

8960383

Citation

Sharifi, A M., and E L. Schiffrin. "Endothelin Receptors Mediating Vasoconstriction in Rat Pressurized Small Arteries." Canadian Journal of Physiology and Pharmacology, vol. 74, no. 8, 1996, pp. 934-9.
Sharifi AM, Schiffrin EL. Endothelin receptors mediating vasoconstriction in rat pressurized small arteries. Can J Physiol Pharmacol. 1996;74(8):934-9.
Sharifi, A. M., & Schiffrin, E. L. (1996). Endothelin receptors mediating vasoconstriction in rat pressurized small arteries. Canadian Journal of Physiology and Pharmacology, 74(8), 934-9.
Sharifi AM, Schiffrin EL. Endothelin Receptors Mediating Vasoconstriction in Rat Pressurized Small Arteries. Can J Physiol Pharmacol. 1996;74(8):934-9. PubMed PMID: 8960383.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Endothelin receptors mediating vasoconstriction in rat pressurized small arteries. AU - Sharifi,A M, AU - Schiffrin,E L, PY - 1996/8/1/pubmed PY - 1996/8/1/medline PY - 1996/8/1/entrez SP - 934 EP - 9 JF - Canadian journal of physiology and pharmacology JO - Can J Physiol Pharmacol VL - 74 IS - 8 N2 - The effects of endothelin-1 (ET-1), a nonselective ETA and ETB receptor agonist, and sarafotoxin S6c, a selective ETB agonist, were investigated in the presence and absence of BQ123 and BQ788, ETA- and ETB-selective antagonists, respectively, in rat mesenteric small arteries, using a perfusion pressurized arteriograph in which segments of vessels were cannulated and exposed to constant pressure and flow. ET-1 (10(-13)-10(-7) M) induced vasoconstriction in both intact and endothelium-denuded arteries in a concentration-dependent manner. BQ123 (10(-7) and 10(-6) M) inhibited the effect of ET-1, displacing the concentration-response curve to the right in a concentration-dependent manner. The effect of ET-1 was not significantly affected by BQ788 (10(-7) and 10(-6) M), a selective antagonist of ETB receptors. Sarafotoxin S6c (10(-11)-10(-7) M) also induced a slight concentration-dependent vasoconstriction. The effect of sarafotoxin S6c (10(-8) M) was inhibited by the ETB-selective antagonist BQ788 (10(-7) M), but was not significantly changed by BQ123 (10(-7) M). Vasoconstriction induced by sarafotoxin S6c (10(-8) M) in a single bolus concentration was significantly greater than the contraction induced by the same concentration as part of a cumulative concentration-response curve, indicating desensitization or downregulation of ETB receptors during the latter. Repeated application of single concentrations of sarafotoxin S6c (10(-8) M) caused progressively smaller contraction of arteries. These results show the existence of both ETA and ETB vasoconstrictor receptors located on smooth muscle of small arteries. They also show that ETB receptors induce a smaller constrictor effect, and rapidly undergo desensitization after sustained or repeated activation. SN - 0008-4212 UR - https://www.unboundmedicine.com/medline/citation/8960383/Endothelin_receptors_mediating_vasoconstriction_in_rat_pressurized_small_arteries_ L2 - http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=8960383.ui DB - PRIME DP - Unbound Medicine ER -