Effects of exendin-4 on GFAP and IL-1βexpression in hippocampi of aged rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of exendin-4 on glial brillary acidic protein (GFAP ) and interleukin-1β(IL-1β) expression in hippocampi of aged rats .Methods Forty-eight healthy male Sprague-Dawley rats ,aged 22-24 weeks ,weighing 500-700 g ,were randomly divided into 4 groups (n=12 each) using a random number tablecontrol group (group C ) ,exendin-4 group (group E ) ,operation group (group O ) and exendin-4 plus operation group (group OE) .The rats were anesthetized with intraperitoneal fentanyl and droperidol .Groups C and E did not receive anesthesia or splenectomy .In O and OE groups ,splenectomy was carried out .In E and OE groups , exendin-4 5 μg/kg was injected intraperitoneally at 30 min before skin incision and 12 h after operation .C and O groups received the equal volume of normal saline instead of exendin-4 .Learning and memory function was assessed using Morris water maze test (escape latency (EL) and total swimming distance (TSD) at 1 day before operation (T0 ) .The fasting blood glucose was measured after anesthesia (T1 ) ,at the end of operation (T2 ) and on postoperative day 1 (T3 ) .The rats were sacrificed after assessment of the cognitive function at T 3 and the hippocampi were removed for determination of the expression of GFAP (by immuno-histochemistry ) and IL-1β(by Western blot ) .Results There was no significant difference in the EL and TSD at T0 between the four groups ( P>0.05) .Compared with group C ,the EL and TSD were significantly prolonged at T3 and fasting blood glucose was increased at T2 ,3 ,and the expression of IL-1βand GFAP was up-regulated at T3 in O and OE groups ( P<0.05) .Compared with group O ,the EL and TSD were significantly prolonged at T3 and fasting blood glucose was decreased at T2 ,3 ,and the expression of IL-1βand GFAP was down-regulated at T3 in group OE ( P<0.05) . Conclusion Exendin-4 can improve the postoperative cognitive function of aged rats by inhibiting inflammatory responses in hippocampi and maintaining stable perioperative blood glucose .