In vitro studies of the modulatory effects of sensory neuropeptides on peripheral blood mononuclear leukocytes of normal and allergic subjects.

The purpose of the present study was to evaluate the modulatory effects of sensory neuropeptides on peripheral blood mononuclear leukocytes of normal and allergic subjects. Peripheral blood mononuclear leukocytes obtained from five normal subjects and from five patients with allergic rhinitis and asthma were incubated with morphine, ACTH, vasoactive intestinal peptide, or substance P at concentrations of 10(-9) M, 10(-7) M, 10(-6) M and suboptimal (0.0125 microgram/mL, 0.025 microgram/mL, and 0.05 microgram/mL) concentrations of PHA. Uptake of 3H-thymidine was evaluated at 72 hours of culture. An inhibitory effect was observed with morphine, ACTH, and substance P while stimulatory effects were seen with vasoactive intestinal peptide, both in normal and in allergic subjects. The results of these preliminary studies provide further evidence for a modulatory role of neuropeptides on the immune function in both normal and allergic subjects.