内皮素-1可使大鼠精囊收缩并增强其对ATP的运动反应。

Endothelin-1 contracts and increases motor responses to ATP in rat seminal vesicle.

作者信息

Luciano L G, D'Orléans-Juste P, Calixto J B, Rae G A

机构信息

Department of Pharmacology, Universidade Federal de Santa Catarina, Florianópolis, Brazil.

出版信息

J Cardiovasc Pharmacol. 1995;26 Suppl 3:S91-4.

PMID:8587479

Abstract

Endothelin-1 (ET-1; 0.3-100 nM) induced graded tonic contractions in rat isolated seminal vesicle, with an EC50 of 7.2 nM and an Emax of 0.24 +/- 0.03 g/100 mg wet tissue. In contrast, norepinephrine (NE) and acetylcholine (ACh) caused short-lasting phasic contractions, yielding EC50s of 8.0 and 30.3 microM and Emaxs of 1.99 +/- 0.21 and 2.16 +/- 0.31, respectively. ET-3 and sarafotoxin S6c were 10- to 30-fold less potent than ET-1. Contractions to ET-1 (1-100 nM) were markedly inhibited by the selective ETA receptor antagonist BQ-123 (300 nM). ET-1 also potentiated, in graded fashion, contractions induced by ATP (1 mM; 30 nM of ET-1 caused a 10-fold potentiation) but not by NE (3 microM) or ACh (10 microM). Indomethacin (5.6 microM) reduced ET-1-induced contractions and abolished the potentiation of responses to ATP. Big ET-1 also contracted the preparation, being 10- to 15-fold less potent than ET-1. Therefore ET-1 causes modest tonic contractions of the rat seminal vesicle via stimulation of ETA receptors and selectively potentiates motor responses to ATP. Eicosanoids of the cycloxygenase pathway are involved in both effects.

摘要

内皮素 -1（ET -1；0.3 - 100 nM）可引起大鼠离体精囊的分级强直收缩，其半数有效浓度（EC50）为7.2 nM，最大效应（Emax）为0.24±0.03 g/100 mg湿组织。相比之下，去甲肾上腺素（NE）和乙酰胆碱（ACh）引起短暂的相性收缩，其EC50分别为8.0和30.3 μM，Emax分别为1.99±0.21和2.16±0.31。ET -3和芋螺毒素S6c的效力比ET -1低10至30倍。选择性ETA受体拮抗剂BQ -123（300 nM）可显著抑制对ET -1（1 - 100 nM）的收缩反应。ET -1还能以分级方式增强由ATP（1 mM）诱导的收缩（30 nM的ET -1可引起10倍的增强），但对NE（3 μM）或ACh（10 μM）诱导的收缩无增强作用。吲哚美辛（5.6 μM）可减少ET -1诱导的收缩，并消除对ATP反应的增强作用。大内皮素 -1也能使该标本收缩，其效力比ET -1低10至15倍。因此，ET -1通过刺激ETA受体引起大鼠精囊适度的强直收缩，并选择性地增强对ATP的运动反应。环氧化酶途径的类花生酸参与了这两种效应。