Inhibition by nonsteroidal antiinflammatory drugs of luminol-dependent human-granulocyte chemiluminescence and [³H]FMLP binding

Abstract

A system is described to evaluate for nonsteroidal antiinflammatory drugs by means of luminol-dependent human-granulocyte chemiluminescence (CL) is described. The CL is produced using either opsonized zymosan (yeast cells) or the soluble chemotactic peptide f-Met-Leu-Phe as the perturbant of the granulocyte membrane. Using either system, the following drug effects 2×10⁻⁵ M were noted: only sulindac sulfide, and not sulindac sulfone or sulindac, displayed marked inhibition of chemiluminescence, following the in vivo data regarding inflammatory effects. The 5-OH indomethacin metabolite was likewise inactive as an inhibitor of CL mirroring in vivo effects. MK(+)410, MK(−)830 and MK835 all showed approximately 50% inhibition of CL, displaying deviation from in vivo data. MK(+)830 markedly stimulated CL, 4–6 times the control (without drug), which is clearly different from its enantiomer, MK(−)830. The reasons for this behavior are unclear. However, receptor binding studies with [³H]FMLP were accomplished in the presence and absence of the various drugs at 2×10⁵ M that were effective inhibitors of chemiluminescence (CL). Indomethacin, MK(−)830 and MK(+)410 had equivalent percent control binding and percent control CL. Sulindac sulfide and MK(+)835 both had higher percent control binding than percent control CL, with MK(+)835 displaying apparent increased numbers of available receptors relative to control. MK(+)830, which produces large increases in CL, produced a minor effect on percent control binding. A direct relationship between binding and CL does not exist with each drug. Chemiluminescence is dependent on ion movement and oxidative metabolism and is a secondary event to agonist-receptor occupation.