CHANGES IN IP(3)R1 AND SERCA2B MESSENGER-RNA LEVELS IN THE GERBIL BRAIN AFTER CHRONIC ETHANOL ADMINISTRATION AND TRANSIENT CEREBRAL ISCHEMIA-REPERFUSION

Despite epidemiological studies indicating a positive relationship bet ween alcohol and stroke, little is known with regard to effect of chro nic alcohol on neuronal injury after stroke. In this study, we examine d the effect of chronic ethanol on mRNA levels of sarcoplasmic or endo plasmic Ca2+-ATPase (SERCA2b) and inositol 1,4,5-triphosphate receptor (IP(3)R1) in gerbils subjected to global cerebral ischemia induced by ligation of both common carotid arteries. Gerbils were given daily by intragastric intubation either a liquid diet containing ethanol (4 g/ kg) or the same diet with an isocaloric amount of sucrose for 35 days. They were subsequently subjected to a 5 min ischemic insult followed by reperfusion for 48 h. In agreement with other studies, ischemic ins ult caused significant decreases (P < 0.05) in mRNA levels of both IP( 3)R1 and SERCA2b in the hippocampal CA1 region but not in the dentate gyrus. Nevertheless, despite a significant (P < 0.05) decrease in SERC A2b mRNA in the Purkinje neurons, chronic ethanol did not alter the ex pression of this mRNA species in the hippocampal CA1 neurons nor did i t alter the decrease in SERCA2b mRNA due to cerebral ischemic insult. Since IP(3)R1 and SERCA2b are key mediators for regulation of intracel lular Ca2+ stores, the decrease in SERCA2b mRNA but not IP(3)R1 mRNA i n cerebellar neurons may be an important mechanism underlying alterati on of calcium homeostasis and cerebellar degeneration upon chronic eth anol consumption. (C) 1998 Elsevier Science B.V.