Effects of Thiol Group Inhibitors on Oxidant Production , Acid Phosphatase Release , and the Intracellular Ca2+ Level in Bovine Neutrophils

초록

The effects of thiol group inhibitors on respiratory burst, degranulation, and intracellular Ca^(2+) level in bovine neutrophils were examined. Superoxide and HOCl production in arnchidonic acid-activated neutrophils and NADPH oxidase activity were inhibited by HgCl₂, NEM, PCMB, and PCMBSA. PMA-stimulated superoxide and H202 generation in neutrophils were inhibited by HgCl₂, NEM, H-7, chlorpromazine, and propranolol, but were not affected by PCMB and PCMBSA The inhibitory effect of NEM on superoxide generation in PMA-activated neutrophils was almost completely prevented by GSH and MPG. The activity of NADPH oxidase, which is obtained from arachidonic acid-activated neutrophils, was inhibited by PMA, and the inhibitory effect of PMA was abolished by HgCl₂ and PCMB. Release of acid phosphatase from activated neutrophils was inhibited by HgCl₂, NEM, PCMB, PCMBSA, EGTA, vempamil, and diltiazem, but was not affected by H-7, chlorpromazine, and propmnolol. The arachidonic acid-induced elevation of Ca^(2+)i was inhibited by HgCl₂, NEM, EGTA, TMB-8, and verapamil, but was not affected by PCMB and PCMBSA. These results suggest that neutrophil responses, including superoxide generation and lysosomal enzyme release, may be influenced by the oxidation of sulfhydryl groups. The protein kinase C-mediated neutrophil response and the intracellular calcium mobilization appear to be affected by a change of intracellular sulfhydryl groups.