Abstract
1. Experiments were designed to investigate the mechanisms underlying the diabetes-related impairment of the vasodilatations of the perfused mesenteric arterial bed induced by acetylcholine (ACh) and K+. 2. In streptozotocin (STZ)-diabetic rats, the ACh-induced endothelium-dependent vasodilatation was attenuated. The dose-response curves for ACh in control and diabetic rats were each shifted to the right by N(G)-nitro-L-arginine (L-NOARG) and by isotonic high K+ (60 mM). The ACh dose-response curves under isotonic high K+ were not different between control and diabetic rats. 3. We also examined the vasodilatation induced by K+, which is a putative endothelium-derived hyperpolarizing factor (EDHF). The mesenteric vasodilatation induced by a single administration of K+ was greatly impaired in STZ-induced diabetic rats. Treatment with charybdotoxin plus apamin abolished the ACh-induced vasodilatation but enhanced the K+-induced response in controls and diabetic rats. After pretreatment with ouabain plus BaCl2, the ACh-induced vasodilatation was significantly impaired and the K+-induced relaxation was abolished in both control and diabetic rats. 4. The impairment of the endothelium-dependent vasodilatation of the mesenteric arterial bed seen in STZ-induced diabetic rats may be largely due to a defective vascular response to EDHF. It is further suggested that K+ is one of the endothelium-derived hyperpolarizing factors and that the vasodilatation response to K+ is impaired in the mesenteric arterial bed from diabetic rats.
Original language | English (US) |
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Pages (from-to) | 549-556 |
Number of pages | 8 |
Journal | British Journal of Pharmacology |
Volume | 130 |
Issue number | 3 |
DOIs | |
State | Published - 2000 |
Externally published | Yes |
Keywords
- Diabetes
- Endothelium
- Endothelium-derived hyperpolarizing factor
- Mesenteric arterial bed
- Rat
- Streptozotocin
ASJC Scopus subject areas
- Pharmacology