Tong L J, Dong L W, Hsu H K, Liu M S
Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, Missouri 63104, USA.
J Surg Res. 1998 Mar;75(2):165-9. doi: 10.1006/jsre.1998.5273.
Changes in the activities of secretory phospholipase A2 (sPLA2) and cytosolic phospholipase A2 (cPLA2) in the rat heart during early hyperdynamic and late hypodynamic phases of sepsis were studied in an attempt to understand the pathophysiology of cardiac dysfunction during sepsis.
Sepsis was induced by cecal ligation and puncture (CLP). Experiments were divided into three groups: control, early sepsis, and late sepsis. Early and late sepsis refers to those animals sacrificed at 9 and 18 h, respectively, after CLP. PLA2 activity was measured based on the rate of hydrolysis of 1-palmitoyl-2-[1-(14)C]-oleoyl phosphatidylcholine.
The results show that under physiological conditions, sPLA2 and cPLA2 activities were time and protein dependent. The optimal Ca2+ concentrations for sPLA2 and cPLA2 activities were 3 mM and 40 microM, respectively. During sepsis, sPLA2 activity was decreased by 25% (P < 0.01) during early phase while it was increased by 49% (P < 0.01) during late phase of sepsis. Similarly, cPLA2 activity was decreased by 23% (P < 0.01) during early sepsis while it was increased by 60% (P < 0.01) during late sepsis.
Since PLA2 functions to maintain cell membrane integrity and function, a biphasic change in sPLA2 and cPLA2 activities may contribute to the development of the two cardiodynamically distinct phases during the progression of sepsis.
研究了脓毒症早期高动力和晚期低动力阶段大鼠心脏中分泌型磷脂酶A2（sPLA2）和胞质型磷脂酶A2（cPLA2）活性的变化，以试图了解脓毒症期间心脏功能障碍的病理生理学。
通过盲肠结扎和穿刺（CLP）诱导脓毒症。实验分为三组：对照组、早期脓毒症组和晚期脓毒症组。早期和晚期脓毒症分别指CLP后9小时和18小时处死的动物。基于1-棕榈酰-2-[1-（14）C]-油酰磷脂酰胆碱的水解速率测量PLA2活性。
结果表明，在生理条件下，sPLA2和cPLA2活性具有时间和蛋白质依赖性。sPLA2和cPLA2活性的最佳Ca2+浓度分别为3 mM和40 microM。在脓毒症期间，sPLA2活性在早期阶段降低了25%（P<0.01），而在脓毒症晚期阶段增加了49%（P<0.01）。同样，cPLA2活性在早期脓毒症期间降低了23%（P<0.01），而在晚期脓毒症期间增加了60%（P<0.01）。
由于PLA2具有维持细胞膜完整性和功能的作用，sPLA2和cPLA2活性的双相变化可能有助于脓毒症进展过程中两个心脏动力学不同阶段的发展。
