Busija D W, Leffler C W
Department of Physiology and Biophysics, University of Tennessee, Memphis 38163.
Am J Physiol. 1989 Jan;256(1 Pt 2):H120-5. doi: 10.1152/ajpheart.1989.256.1.H120.
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.
我们研究了前列腺素类物质在新生猪荷包牡丹碱诱发癫痫发作中的作用。采用闭合颅窗法和前列腺素类物质放射免疫分析法，我们发现癫痫发作期间软脑膜小动脉扩张；这种扩张与皮质蛛网膜下脑脊液（CSF）中前列腺素E2、6-酮前列腺素F1α、前列腺素F2α和血栓素B2水平升高有关。使用放射性微球，我们发现仔猪癫痫发作期间脑血流量（CBF）显著增加。为了研究环氧化酶药理阻断的作用，我们测定了用吲哚美辛（5mg/kg）预处理的仔猪以及相应的一组体温降低的仔猪的CBF，以确保癫痫发作前的CBF值相似。在体温降低的组中，癫痫发作期间CBF增加，但吲哚美辛组癫痫发作期间所有脑区的CBF增加均显著减少。我们得出结论：1）荷包牡丹碱诱发的癫痫发作导致软脑膜小动脉扩张和CBF增加；2）癫痫发作期间CSF中前列腺素类物质水平升高；3）用吲哚美辛预处理可严重抑制癫痫发作期间CBF的增加。
