Effects of Diabetes, Insulin Treatment, and Osmolality on Contractility of Isolated Rat Resistance Arteries

摘要: The effects of osmolality, diabetes, and insulin-treatment on microvascular contractility were examined in mesenteric resistance arteries (internal diameter approximately 250 microns) isolated from streptozotocin-induced diabetic rats, rats treated with 1-3 U insulin/day during the week before being killed, age- sex-matched control rats. Vessels mounted a myograph for isometric tension recording responses generated physiological salt solutions varying amounts glucose or mannitol added. passive response (expressed as vessels would maintain if relaxed exposed to transmural pressure 100 mmHg), maximal noradrenaline, produced by partial depolarization 50 mmol/l potassium not dependent concentrations bathing medium; also, these dissimilar three groups tested. sensitivity however, was inversely related concentration (P < 0.01) medium without significant differences slopes regression lines between rat groups. Moreover, less sensitive noradrenaline than rats; insulin-treated animals had lowest noradrenaline. These data suggest that independently affect endogenous neurotransmitter,