The influence of local intravital administration of endothelin-1 on microvessels of rat small intestine was investigated by laser-doppler flowmetry and by intravital microscopy. Changes in vascular diameter and red blood cell velocity in microvascular beds were determined by using a high-speed video camera system. Endothelin-1 at concentrations in the 100 pmol/kg to 1 nmol/kg range caused the vasoconstriction of arterioles in a dose-dependent manner, and the constrictive actions were dominant especially in the terminal arteriole (3A). A decrease in red blood cell velocity was observed with the endothelin-induced arteriolar constriction, and was followed by mucosal ischemia. The present study also revealed that endothelin-1 is more potent as a constrictor on arteriolar than on venular smooth muscle. These results indicate that endothelin-1 is a potent vasoconstrictive peptide in microvessels of rat intestine and suggest that endothelin may participate as a modulator in the regulation of intestinal mucosal blood flow under physiologic conditions.
|ジャーナル||Journal of Vascular Medicine and Biology|
|出版ステータス||Published - 1991 12月 1|
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