AJP - Heart and Circulatory Physiology, Vol 256, Issue 1 120-H125, Copyright © 1989 by American Physiological Society
Role of prostanoids in cerebrovascular responses during seizures in piglets
D. W. Busija and C. W. Leffler
Department of Physiology and Biophysics, University of Tennessee, Memphis 38163.
We examined the role of prostanoids to bicuculline-induced seizures in
newborn pigs. Using the closed cranial window method and radioimmunoassay
for prostanoids, we found that pial arterioles dilated during seizures;
this dilation was associated with increased cortical periarachnoid
cerebrospinal fluid (CSF) levels of prostaglandin E2, 6-ketoprostaglandin
F1 alpha, prostaglandin F2 alpha, and thromboxane B2. Using radioactive
microspheres, we found cerebral blood flow (CBF) increased dramatically
during seizures in piglets. To examine the effects of pharmacological
blockade of cyclooxygenase, we determined CBF in piglets pretreated with
indomethacin (5 mg/kg) and in a corresponding group of piglets made
hypothermic to be sure preseizure CBF values were similar. In the
hypothermic group, CBF increased during seizure, but the increase in CBF
during seizure in the indomethacin group was reduced dramatically in all
brain areas. We conclude that 1) bicuculline-induced seizures result in
pial arteriolar dilation and increased CBF; 2) CSF levels of prostanoids
increase during seizures; and 3) pretreatment with indomethacin severely
blunts increases in CBF during seizures.
