Endothelin and platelet activating factor. Possible indices for biocompatibility of hemodialysis.

Abstract

To clarify the roles of endothelin (ET: vasoconstrictor) and platelet activating factor (PAF: vasodilator) in hemodialysis (HD), intradialytic changes in those substances were compared by a crossover study between HD with regenerated cellulose (RC) and polymethylmethacrylate (PMMA) membranes using currently developed radioimmunoassay methods. Hemodialysis patients demonstrated higher plasma ET values than normal controls, and hypertensive HD cases showed the highest levels. Although ET decreased significantly during the initial stage of HD with both membranes, the decreasing rates were greater in the group with intradialytic hypotension than those in the normotensive group. Plasma PAF did not differ among normal controls, hypertensive HD, and normotensive HD patients. Platelet activating factor tended to increase during HD in both hypotensive and normotensive groups; however, the increasing rates were greater in HD with RC than those with PMMA. These results indicate that the decrease in ET may partially contribute to the initiation of HD induced hypotension. Because PAF is an intracellular mediator, and there is an intradialytic increase in PAF with RC membrane, PAF should be regarded as one of the indices of membrane biocompatibility.