[Interaction between angiotensin II and endothelin isoforms in the pithed rat].

The 3 isoforms of endothelin (ET) (potent peptidic vasoconstrictor isolated from endothelial cells) induce biphasic pressor effects when given intravenously: a transient hypotension followed by a long-lasting hypertension. The aim of this work was to study the regulatory effect of vascular tone on ET-induced pressor responses in the pithed rat. After pithing, diastolic blood pressure (DBP) was elevated by continuous perfusion of angiotensin-II (AII) or methoxamine (MTX).

Endothelium independent protective effect of NG-monomethyl-L-arginine on endotoxin-induced alterations of vascular reactivity.

The effects of NG-monomethyl-L-arginine (NMMA), a specific inhibitor of nitric oxide (NO) synthesis was tested on the endotoxin-induced alterations of alpha-adrenoceptor function. In isolated aorta, there was no significant difference in the tension induced by phenylephrine (PE, 10 microM) on rings removed from control and endotoxin injected rats (10 mg/kg, ip). However, a lack of tonicity of the contraction was observed in rings of shocked rats (8 +/- 2.

Cross-desensitization between angiotensin II and endothelin-1 in the pithed rat.

It has been shown that in vitro angiotensin II (Ang II) potently downregulates endothelin-1 (ET-1) binding sites. In this study, we investigated in vivo the interactions between the renin-angiotensin system and ET-1. Sprague-Dawley rats were pithed, ventilated, and diastolic blood pressure (DBP) was recorded.

Endothelium-dependent vasorelaxation induced by Cn-acetal plasmalogens.

In this study the effects of the synthetic acetal plasmalogens (AP) C17-AP, C13-AP, C9-AP on isolated rabbit aorta were investigated with emphasis on their putative relationship with endothelium-dependent relaxing factor (EDRF). The various AP were obtained by total synthesis from the related fatty acid chlorides. In isolated rabbit aorta precontracted with phenylephrine (PE, 10(-7) M), C17-AP (greater than 10(-6) M) and C13-AP (greater than 10(-5) M) exerted an endothelium-dependent relaxation (EDR).