Effects of dipyridamole in spontaneously hypertensive rabbits with diffuse chronic cerebral ischemia.
The effect of intravenous dipyridamole (0.7 mg/kg) on cerebral blood flow (CBF), mean arterial blood pressure (MABP), heart rate, respiration rate, cerebral electrical activity, arterial blood gases, pH, and glucose was investigated in 14 normotensive and 14 stroke-prone spontaneously hypertensive anesthetized rabbits. CBF was measured by hydrogen and heat clearance. In both groups, MABP decreased (normotensive: -24 mm Hg, hypertensive: -47 mm Hg; ANOVA: P < 0.0001) and CBF increased (normotensive: +59 ml/100 g/min, hypertensive: +72 ml/100 g/min; ANOVA: P < 0.0002). CBF returned to the initial level 21 min later in hypertensive than in normotensive rabbits. Changes in other parameters were insignificant. In additional experiments, 30 mg/kg theophylline entirely prevented the cerebral vasodilator and systemic hypotensive effects of dipyridamole in both normotensive and hypertensive rabbits. We conclude that, in stroke-prone spontaneously hypertensive rabbits, the longer-lasting and larger CBF increase in response to dipyridamole may be attributed to reversible functional changes in the cerebral vasculature resulting from hypertension.
Hegedüs
K
K
Department of Neurology and Psychiatry, University Medical School, Debrecen, Hungary.
Fekete
I
I
Molnár
L
L
D000704:Analysis of Variance; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002545:Brain Ischemia / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004176:Dipyridamole / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000503:physiopathology; D007275:Injections, Intravenous; D008297:Male; D011817:Rabbits
D004176:Dipyridamole