Cardiovascular responses evoked by endothelin-1(1-31) microinjected into the nucleus tractus solitarius

Abstract

Abstract: AIM: To observe the cardiovascular functions of endothelin-1(1-31)[ ET-1(1-31)] within the nucleus tract solitarius(nucleus tracts solitarius, NTS) and explore their mechanism.METHODS: 90 male SD rats were included into the present study. Among them, 50 were randomized into bilateral or unilateral microinjection of ET-1(1-31)(0.5-2.0 pmoL)or aCSF (100 nL) group, in which ET-1(1-31) (0.5-2.0 pmoL) or aCSF (100 nL) was bilaterally or unilaterally applied to observe the dose-dependant responses of ET-1(1-31) within the NTS. ET-1(1-31) (1.0 pmol) or aCSF (100 nL) was bilaterally applied into the NTS to observe the influences of ET-1(1-31) (1.0 pmoL) on the arterial baroreflex function (BRS) within the bilateral NTS in 11 rats. ET_A receptor antagonist BQ₁₂₃, ET_B receptor antagonist BQ₇₈₈or non-selective glutamate receptor antagonist kynurenine (KYN) was prior applied to explore the mechanism of ET-1(1-31) within the NTS in 29 rats.RESULTS: Bilateral or unilateral microinjection of ET-1(1-31) into the NTS produced dose-dependant hypotension and bradycardia of rats.Bilateral microinjection of ET-1(1-31) into the NTS significantly decreased the BRS function.Pretreatment with BQ₁₂₃ or KYN significantly decreased BP and HR responses induced by unilateral microinjection of ET-1(1-31) (1.0 pmol) into the NTS. There was no obvious influence to BP and HR responses treatment with BQ₇₈₈.CONCLUSION: ET-1(1-31) within the NTS produces hypotension and bradycardia, mediated by ET_A receptors and glutamate receptor at least partly.

Key words: Endothelin-1(1-31), Nucleus tract solitarius, Cardiovascular, Baroreflex

CLC Number:

R965.2

LI Pei-wu, WANG Xian-kun, CHONG Xiao-qin, LI Pei-jie, CUI Hong-bin, LU Yan, FU Zhong-xue. Cardiovascular responses evoked by endothelin-1(1-31) microinjected into the nucleus tractus solitarius[J]. Chinese Journal of Clinical Pharmacology and Therapeutics, 2013, 18(7): 754-759.

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