title: Effects of streptozotocin-diabetes on sympathetic nerve, endothelial and smooth muscle function in the rat mesenteric arterial bed.
abstract: Mesenteric arterial function was assessed in constantly perfused preparations isolated from rats 12 weeks after treatment with streptozotocin (65 mg kg-1, i.p.) to induce diabetes. Frequency-dependent vasoconstrictor responses to electrical field stimulation of sympathetic nerves (4-32 Hz, 0.1 ms, 90V, 30 s) were severely attenuated in preparations from streptozotocin-diabetic rats, although dose-dependent vasoconstrictions to the sympathetic cotransmitters noradrenaline and ATP, as well as to potassium chloride, were not significantly changed. Dose-dependent relaxations to the endothelium-dependent vasodilators acetylcholine and ATP were significantly impaired in preparations from streptozotocin-diabetic rats, although endothelium-independent vasodilatation to sodium nitroprusside was unimpaired. These results suggest 12 weeks after induction of streptozotocin-diabetes in rats there is pre-junctional impairment of sympathetic neurotransmission and impaired endothelial function of the mesenteric arteries. This is in contrast to our previous findings that at 8 weeks after induction of streptozotocin-diabetes sympathetic nerve and endothelial function is normal, although sensory-motor vasodilatation is severely attenuated. It is suggested that selective changes occur in mesenteric arterial function after streptozotocin treatment depending on the duration of diabetes; sensory-motor nerves are affected first, followed by sympathetic nerves and the endothelium, while the smooth muscle is relatively resistant to change.
authors.affiliation: Department of Anatomy and Developmental Biology, University College London, UK.
authors.forename: V
authors.initials: V
authors.lastname: Ralevic
authors.forename: A
authors.initials: A
authors.lastname: Belai
authors.forename: G
authors.initials: G
authors.lastname: Burnstock
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D013311:Streptozocin; D000109:Acetylcholine