RELATIONSHIP, BETWEEN THE CHEMILUMINESCENT RESPONSE OF BOVINE NEUTROPHILS AND CHANGES IN INTRACELLULAR FREE CALCIUM-CONCENTRATION

The relationship between luminol dependent chemiluminescent (LDCL) res ponse and changes in intracellular free Ca2+ concentrations in the bov ine neutrophils was evaluated. LDCL responses and changes in intracell ular Ca2+ concentrations of neutrophils were clearly detected by the s timulation with opsonized zymosan (OPZ), concanavalin A (ConA), heat-a ggregated IgG (H-agg.IgG) and phorbol myristate acetate (PMA). Pattern s of LDCL responses and intracellular Ca2+ of neutrophils showed chara cteristic features for each stimulant, PMA was a weak stimulant of the intracellular Ca2+ concentration, whereas it was a strong stimulant o f LDCL response. Con A strongly stimulated an increase in the intracel lular Ca2+ concentration, but was a weak stimulant of LDCL response. L DCL response of intracellular Ca2+-depleted neutrophils treated with i onomycin, stimulated with each stimulant was inhibited markedly withou t extracellular Ca2+. The sustained phase of intracellular Ca2+. Conce ntrations stimulated with OPZ was inhibited significantly (P < 0.05) b y the preincubation with anti-CD18 antibody, whereas the transient pha se of intracellular Ca2+ concentrations was not inhibited. These resul ts indicate that LDCL response is regulated at least in part by the el evation of the intracellular Ca2+, and a rise in intracellular Ca2+ co ncentration, which may be mediated by specific receptors appears to be essential in the LDCL response of bovine neutrophils.