Effect of diabetes mellitus on responses of the basilar artery in rats to products released by platelets.
OBJECTIVE
Aggregation and adherence of platelets to vascular endothelium are increased during diabetes mellitus, and thus responses of cerebral arteries to products released by platelets may have important implications for the pathogenesis of stroke during diabetes. The goal of this study was to determine whether responses of the basilar artery to products released by platelets are altered during diabetes.


METHODS
A craniotomy was performed over the ventral medulla to expose the basilar artery. Diameter of the basilar artery was measured using intravital microscopy in nondiabetic and diabetic (50-60 mg/kg i.p. streptozotocin) rats in response to adenosine 5'-diphosphate, serotonin, and the thromboxane analogue U-46619.


RESULTS
Topical application of 10 and 100 microM adenosine 5'-diphosphate produced only minimal changes in diameter of the basilar artery that were similar in nondiabetic and diabetic rats (p greater than 0.05). At 0.01, 0.1, and 1.0 microM serotonin produced dose-related constriction of the basilar artery that was similar in nondiabetic and diabetic rats (p greater than 0.05). At 0.1 and 1.0 microM U-46619 also produced similar dose-related constriction of the basilar artery in nondiabetic and diabetic rats (p greater than 0.05).


CONCLUSIONS
These findings suggest that responses of the basilar artery to products released by platelets are not altered by diabetes mellitus. Thus, it does not appear that alterations in reactivity of the basilar artery to products released by platelets contribute to the pathogenesis of stroke during diabetes.
Mayhan
W G
WG
Department of Physiology and Biophysics, University of Nebraska Medical Center, Omaha 68198.
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000818:Animals; D001488:Basilar Artery / Q000187:drug effects*; D001792:Blood Platelets / Q000378:metabolism; D002561:Cerebrovascular Disorders / Q000503:physiopathology; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D008297:Male; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology*; D051381:Rats; D012701:Serotonin / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects
D011450:Prostaglandin Endoperoxides, Synthetic; D012701:Serotonin; D000244:Adenosine Diphosphate; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid