Kv. Dubinin et al., IMMUNOMODULATING EFFECT OF MET-ENKEPHALIN ON DIFFERENT STAGES OF LYMPHOCYTE-PROLIFERATION INDUCED WITH CONCANAVALIN-A IN-VITRO, Immunopharmacology and immunotoxicology, 16(3), 1994, pp. 463-472
Met-enkephalin (ME) in the range of concentrations 10(-15) M to 10(-9)
M has exhibited an immunomodulating effect on concanavalin A (Con A)
induced proliferation of mice Lymphocytes from lymph nodes in vitro. T
he effect of ME was shown to vary with the stage of lymphocyte activat
ion and to depend on the mitogen dose. In the case that ME and Con A w
ere injected simultaneously, at the zero time of proliferation, maximu
m inhibition was observed on the first and fourth days. In an other se
t of experiments when ME was added at intervals of 4 hours before meas
uring the proliferation response value, both inhibition (after 24 hour
s of proliferation) and stimulation (after 28 and 96 hours) were obser
ved. Opioid ligands of various classes were found to act in the same m
anner as ME. Naloxone was shown to block the immunomodulating effect o
f opioids.