Reversibility of leukocyte dysfunction in rats with obstructive jaundice

Abstract

Background The role of leukocytes in obstructive jaundice is obscure and the effect of relieving cholestasis on leukocyte function is unclear. We postulated that cholestasis affects systemic polymorphonuclear leukocyte function by deranging phagocytosis and hydrogen peroxide release and the leukocyte dysfunction is reversible by internal and external biliary drainage. Materials and methods Sixty male Sprague Dawley rats were randomly assigned to four groups: obstructive jaundice (OJ), sham operation (SH), OJ with internal drainage (ID), and OJ with external drainage (ED). The phagocytic functions of neutrophils and monocytes in whole blood were measured with flow cytometry using fluorescent microspheres. Intracellular hydrogen peroxide production by leukocytes was assessed with flow cytometry using dihydrorhodamine-123 as probes. Results Leukocyte count and percentage of monocytes in rats with OJ was significantly increased compared with SH rats ( P < 0.001). These elevations could be reversed by both ID and ED method ( P < 0.001). The phagocytic function of neutrophils and monocytes was significantly depressed in OJ rats compared with that in SH rats ( P < 0.001). After relief of the OJ, the suppressed phagocytic function of neutrophils and monocytes was completely improved in ID rats (ID versus OJ, P < 0.001), but only partially reversed in ED rats. The hydrogen peroxide production by monocytes and lymphocytes was significantly increased in OJ rats ( P < 0.05). ID reversed the increased hydrogen peroxide generation ( P < 0.05), but ED only partially did. Conclusions In our rodent model of biliary obstruction, deranged phagocytosis, and hydrogen peroxide generation by leukocytes was found. Internal drainage is superior to external drainage for reversal of the distorted leukocyte function.