Aldosterone alters the participation of endothelial factors in noradrenaline vasoconstriction differently in resistance arteries from normotensive and hypertensive rats

作者：Xavier Fabiano E; Blanco Rivero Javier; Avendano Maria Soledad; Sastre Esther; Yela Ruben; Velazquez Kyra; Salaices Mercedes; Balfagon Gloria^*

来源：European Journal of Pharmacology, 2011, 654(3): 280-288.

DOI：10.1016/j.ejphar.2011.01.007

• Aldosterone
• Mesenteric resistance artery
• Nitric oxide
• Superoxide anion
• Thromboxane A(2)
• Prostaglandin I(2)

This study analyzed the effect of aldosterone (0.05 mg/kg per day, 3 weeks) on vasoconstriction induced by noradrenaline in mesenteric resistance arteries from WKY rats and SHR. Contraction to noradrenaline was measured in mesenteric resistance arteries from untreated and aldosterone-treatedrats from both strains. Participation of nitric oxide (NO), superoxide anions, thromboxane A(2) (TXA(2)) and prostacyclin in this response was determined. 6-keto-prostaglandin (PG)F1 alpha and thromboxane B(2) (TxB(2)) releases were determined by enzyme immunoassay. NO and superoxide anion release were also determined by fluorescence and chemiluminiscence, respectively. Aldosterone did not modify noradrenaline-induced contraction in either strain. In mesenteric resistance arteries from both aldosterone-treated groups, endothelium removal or preincubation with NO synthesis inhibitor L-NAME increased the noradrenaline-induced contraction, while incubation with the superoxide anion scavenger tempol decreased it. Preincubation with either the COX-1/2 or COX-2 inhibitor (indomethacin and NS-398, respectively) decreased the noradrenaline contraction in aldosterone-treated animals, while this response was not modified by COX-1 inhibitor SC-560. TxA(2) synthesis inhibitor (furegrelate), or TxA(2) receptor antagonist (SQ 29 548) also decreased the noradrenaline contraction in aldosterone-treated animals. In untreated SHR, but not WKY rats, this response was increased by L-NAME, and reduced by tempol, indomethacin, NS-398 or SQ 29 548. Aldosterone treatment did not modify NO or TxB(2) release, but it did increase superoxide anion and 6-keto-PGF(1alpha) release in mesenteric resistance arteries from both strains. In conclusion, chronic aldosterone treatment reduces smooth muscle contraction to alpha-adrenergic stimuli, producing a new balance in the release of endothelium-derived prostanoids and NO.

• 出版日期2011-3-11