Arachidonic acid activatable electrogenic H+transport in the absence of cytochromeb558in human T lymphocytes

Abstract
To test the suggested structural relationship between the electrogenic H+ transporting system and the NADPH oxidase of phagocytes, the existence of the enzyme and the transport process was investigated in human tonsillar T lymphocytes. It is shown that tonsillar T cells possess an arachidonic acid activatable, Cd2+- and Zn2+-sensitive electrogenic H+ efflux pathway with similar properties as reported earlier in various phagocytic cells. The presence of cytochrome b 558, the membrane component of the oxidase, could not be detected in tonsillar T lymphocytes either by immunoblot or by flow cytometric analysis. It is suggested that the electrogenic H+ transporting pathway is structurally independent of the NADPH oxidase complex.