The Effect Of Parecoxib On Postoperative Cognitive Of Aged Male Rats

Objective: Injecting cox-2inhibitors parecoxib to aged male Sprague-Dawley rats, we observe the drug’s effect on postoperative cognitive, theneurons，and the expression of proinflammatory cytokines in the rats’hippocampal CA1area, for investigating the effect of parecoxib onpostoperative cognitive of aged male rats.Methods:50elderly Sprague-Dawley male rats were divided into threegroups by Computer random number method: control group (group NS)10rats, did not receive operation; surgery group (group Sur)20rats,received abdominal surgery; surgery and parecoxib group(groupPare)20rats,received abdominal surgery and were injected parecoxib;Rats of Group Pare were injected the same dose1mL/Kg(40mg, dilutedby0.9%sodium chloride injection to8mL) of parecoxib into theabdomen,while rats of group NS and group Sur were injected the samecapacity of0.9%sodium chloride injection. Group Pare were repeatedlyinjected the same dose of parecoxib at6th hour,2nd and3th day afteroperation.Group NS and group Sur were injected the same capacity of0.9%sodium chloride injectionin at the same time. Morris Water Mazeexperiment was used to test the postoperative cognitive of aged malerats,and we used Hematoxylin-Eosin staining to observe neurons, immunohistochemical staining to inspect the expression of IL-1β andIL-6,TUNEL technique to inspect the apoptosis of hippocampal CA1area.Results:1.Result of the Morris Water Maze experiment The experimentalgroup animals could find the platform in a shorter time and distance onplace navigation test after training(before operation); and they could stayfor a longer time in the target quadrant than other quadrants. their motiontracks converged on the target quadrant on spatial probe test. The MorrisWater Maze experiment before operation showed no statistical difference(P>0.05). Rats of group Sur had to swim for a longer distance to find theplatform, the escape latency was longer than group NS(P<0.01) andgroup Pare(P<0.05) on place navigation test at3th day after operation.While on spatial probe test,rats of group Sur stayed in the target quadrantwithout platform for a sharply shorter time than rats of group NS andgroup Pare at3th day after operation(P<0.01). There were no statisticaldifference(P>0.05) on both place navigation test and spatial probe test at7th day after operation.2.Neuronal density of hippocampal CA1area Nerve cells ofhippocampal CA1area from group NS arranged compactly,continuouslyand evenly. Their forms were full and intact, and nucleolus clearly locatedin the center of the nucleus. Nerve cells of group Sur had some damage. The cells arranged mussily.Their tissue structures were slightly obscure,and the neuronal density had a certain amount reducing. Neuronal densityof group Sur had no difference at3th day and7th day. Nerve cells ofgroup Pare had no obvious damage,arranging slightly sparsely, andpyknosis of nucleus were rare.Rats’neuronal density declined than groupNS at3th day(P<0.01). While neuronal density of group Pare had noobvious change(P>0.05). Neuronal density of group Sur declined thangroup NS at7th day(P<0.01). Group Pare had no obviouschange(P>0.05).3.Expression in IL-1β and IL-6of hippocampal CA1area There werelow expressions of IL-1β and IL-6in hippocampal CA1area from rats ofgroup NS, and this expression≤5%, marked as(－). There were highexpressions of IL-1β and IL-6in hippocampal CA1area of rats fromgroup Sur at3th day, marked as(++).Expressions of IL-1β and IL-6inhippocampal CA1area of rats from group Pare was rare, all markedas(－). Comparing group Sur with group NS and group Pare, there bothwere remarkable statistical differences(P<0.01). The expressions of IL-1βand IL-6in hippocampal CA1of group Sur had a vast reducing at7thday,marked as(+). There were no statistical differences between groupPare and group NS at3th day and7th day(P>0.05).4.Apoptosis of hippocampal CA1area There were a few of apoptoticcells in group NS’rats’hippocampal CA1area. More apoptotic cells from group Sur were found. A few apoptotic cells from group Pare werefound. Comparing group Pare with group NS, there were no statisticaldifferences(P>0.05) at3th day and7th day.Comparing group Sur withgroup NS and group Pare, there were remarkable statisticaldifferences(P<0.01) at the each same time point.Conclusion:1. To aged male Sprague-Dawley rats, high expressions of IL-1β andIL-6in hippocampal CA1area can induce postoperative cognitivedysfunction.2. To aged male Sprague-Dawley rats, parecoxib can effectively restrainthe expression of IL-1β and IL-6in hippocampal CA1area, and reduceinflammatory response to improving the aged rat’s postoperativecognitive.3. To aged male Sprague-Dawley rats, parecoxib can restrain apoptosis ofnerve cell in hippocampal CA1area,and protect nervus.