Secretory event in intestinal grafts during preservation ischemia

Background. Ischemia triggers secretion of proteins from the intestine, inc luding type II secretory phospholipase A(2) (sPLA(2)). This "secretory even t" was studied in intestinal grafts during the first few hours of preservat ion by measuring total protein, sPLA(2), and other enzymes in the UW preser vation solution over time. The effect of PX-13, a PLA, inhibitor, was also studied, Materials and methods. Twenty-five centimeter intestinal grafts were harves ted from Lewis rats, hushed, and preserved in UW solution +/- PX-13 at 4 de grees C. UW samples from 0 to 48 h (n = 5 each) were analyzed for total pro tein, sPLA(2), lactate dehydrogenase (LDH), N-acetylglucosamine (NAGA), and lysozyme. Nonpreserved grafts were homogenized in PBS as tissue controls, Standard biochemical methods were used for all assays, Results. Total protein increased rapidly by 5 min, continued to rise more s lowly until 30 min, and then stabilized. The most significant increase in s PLA(2) activity occurred between 90 and 180 min. NAGA increased most marked ly between 30 and 180 min, while LDH increased in the first 30 min, althoug h the level of both enzymes was negligible compared to tissue enzyme, Lysoz yme levels were minimal at all times. PX-13 decreased sPLA(2) activity mark edly at all time points, Conclusion. Total protein levels increased before sPLA(2), suggesting that sPLA(2) may be secreted in response to other proteins or enzymes released e ven earlier during preservation (e.g., cytokines). These elevations do not appear to be caused by cell death. Phospholipase A(2) secretion may be bloc ked, and this may greatly improve the outcome of intestinal preservation. ( C) 1999 Academic Press.