严重烧伤大鼠胃粘膜血流量和Na^＋—K^＋—ATP酶活性的改变及对胃粘膜电位差的影响

目的观察大鼠严重烧伤后胃粘膜血流量(GMBF)和Na+-K+-ATP酶活性的变化,探讨其对胃粘膜电位差(GTPD)的影响. 方法制作烧伤大鼠模型,分别采用激光多普勒微循环血流计、电生理记录仪和生化法,检测大鼠伤前及伤后3、6、12、24、48 h时GMBF、GTPD和胃粘膜Na+-K+-ATP酶活性的改变;另设正常大鼠为对照组,于相同时相点检测以上指标.随后对各指标进行相关性分析. 结果与对照组比较,大鼠烧伤后3 ～24 h GMBF与Na+-K+-ATP酶活性均明显降低(P<0.05～0.01),GTPD于伤后6～48 h明显下降(P<0.05～0.01),3项指标均于12 h时降至最低.相关性分析结果显示Na+-K+-ATP酶活性随GMBF的降低而下降(r=0.417,P<0.01);GMBF的减少或Na+-K+-ATP酶活性的降低,均可引起GTPD降低(r=0.453或0.527,P<0.01). 结论大鼠严重烧伤后,GMBF减少,Na+-K+-ATP酶活性降低,二者均为引起胃粘膜屏障功能受损的主要原因.

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OBJECTIVE: To investigate the postburn changes in gastric mucosal blood flow (GMBF) and Na(+)-K(+)-ATPase activity and their effects on gastric transmucosal potential difference (GTPD) in severely scalded rats. METHODS: Rats were inflicted with hot water scald on the back. Laser Doppler blood flow meter, electric physiological recorder meter and biochemical method were employed in the study to determine the changes in GMBF, GTPD and gastric mucosal Na(+)-K(+)-ATPase activity in the rats before injury and at 3, 6, 12, 24 and 48 PBHs. Normal rats served as controls, The above indices were also detected at the corresponding time points. All the data was collected and analyzed for their correlation. RESULTS: The GMBF and Na(+)-K(+)-ATPase activity was at 3 - 24 PBHs were evidently lower in the scalded rats than those in controls (P < 0.05 - 0.01). GTPD was decreased significantly at 6 - 48 PBHs (P < 0.05 - 0.01). was above three indices reached the lowest values at 12 PBH. By correlation analysis the results indicated that the Na(+)-K(+)-ATPase activity The decreased in accordance with a decrease in GMBF (r = 0.527, P < 0.01). The GTPD decrease could both be induced by GMBF decrease and Na(+)-K(+)-ATPase activity decrease (r = 0.453 and 0.527, respectively, P < 0.01). CONCLUSION: The decrease in GMBF and Na(+)-K(+)-ATPase activity occurred in severely scalded rats, both changsh might be the major cause of postburn gastric mucosal barrier injury.