Effects of sulfhydryl reagents on phagocytosis and exocytosis in rabbit polymorphonuclear leukocytes.
The effect of sulfhydryl reagents on phagocytosis and concomitant enzyme release and on ionophore A 23187 + Ca2+-induced exocytosis in rabbit polymorphonuclear leukocytes (PMN's) was studied. Membrane-penetrating sulfhydryl reagents such as cytochalasin A and N-naphthylmaleimide in micromolar concentrations inhibit both phagocytosis and exocytosis. Poorly penetrating reagents such as p-chloromercuribenzene sulfonate (pCMBS) and 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB), inhibit only in high concentrations (pCMBS), or they are ineffective as inhibitors (DTNB). Inhibition by pCMBS is not reversed by glutathione or dithiothreitol; this suggests that some pCMBS probably enters the cell. Specific intracellular sulfhydryl compounds appear to be essential in the cellular apparatus involved in phagocytosis and exocytosis; various possibilities are considered. A concentration of N-naphthylmaleimide which completely inhibits phagocytosis and exocytosis leaves cellular ATPase activity intact.
D002731:4-Chloromercuribenzenesulfonate / Q000494:pharmacology; D003572:Cytochalasins / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects*; D005978:Glutathione / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D009113:Muramidase / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology; D010587:Phagocytosis / Q000187:drug effects*; D013439:Sulfhydryl Reagents / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D003572:Cytochalasins; D007476:Ionophores; D008301:Maleimides; D013439:Sulfhydryl Reagents; D002731:4-Chloromercuribenzenesulfonate; D009113:Muramidase; D005978:Glutathione