title: Sensory neuropeptides (substance P) and 4-11 SP enhance human neutrophils chemiluminescence; the role of L-arginine.
abstract: Investigations on the effect of a naturally occurring neuropeptide, substance P (SP) and one of its synthetic analogues, 4-11 SP, on luminol-enhanced chemiluminescence (CL) of human polymorphonuclear leukocytes (PMN) are presented. Both peptides elicited a strong burst of CL with different time course and dose-response curves. SP- and tuftsin-induced CL were similar, both peptides sharing a Lys-Pro-Arg terminal; 4-11 SP, which lacks the terminal arginine, peaked earlier than the natural peptide. Surprisingly when PMN were pre-incubated with L-arginine (L-Arg) this enhancing effect was abolished or diminished. L-Arg and an L-Arg synthetic derivative (PCF-39) were also evaluated; PCF-39 strongly increased the PMN CL, while L-arginine showed a significant CL enhancement only in 43% of the donors tested. Peptide- and arginine-induced CL were Ca++/MG++ dependent.
mesh_terms: D001120:Arginine / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008163:Luminescent Measurements; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D010446:Peptide Fragments / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013373:Substance P / Q000494:pharmacology*; D014405:Tuftsin / Q000494:pharmacology
chemical_list: D010446:Peptide Fragments; D013373:Substance P; C032682:substance P (4-11); D001120:Arginine; D014405:Tuftsin