Stimulation of peritoneal synthesis of vasoactive prostaglandins during peritonitis in patients on continuous ambulatory peritoneal dialysis.

The peritoneal generation of arachidonic acid metabolites was studied in eight patients with end-stage renal disease undergoing continuous ambulatory peritoneal dialysis (CAPD) during infection-free periods and during bacterial peritonitis. The prostacyclin metabolite 6-keto-PGF1 alpha was found to be the major prostanoid generated by human peritoneal mesothelium (1090 ng (6h)-1, SEM 86, n = 8) followed by lesser amounts of PGE2 (142 ng (6 h)-1, SEM 26, n = 8), PGF2 alpha (162 ng (6 h)-1, SEM 27, n = 8) and TXB2 (59 ng (6 h)-1, SEM 5, n = 8). During peritonitis a significant increase of all prostaglandins and TXB2 occurred (P less than 0.001). The ratio of the vasodilating prostaglandins and their metabolites (PGE2 and 6-keto-PGF1 alpha) to the vasoconstrictors and their metabolites (PGF2 alpha and TXB2) increased from 6.6 to 10.5 during peritoneal inflammation. Augmented peritoneal clearances of creatinin and urea and increased losses of proteins during peritonitis as well as the enhanced peritoneal generation of prostanoids were reduced to basal values by adequate antibiotic therapy. The present results suggest that the increased peritoneal blood flow during peritonitis, probably responsible for the observed changes of peritoneal transport properties, may be induced by a change in the ratio of vasoactive prostaglandins generated by peritoneal mesothelial cells.