Acute effect of a single infusion of papaverine on human peripheral lymphocyte.

It has been reported that drugs which modulate the intracellular levels of 3' 5' cyclic adenosinemonophosphate (cAMP) interfere with the cellular function of the immune system. In this work, papaverine, a drug effective in elevating cAMP levels, was observed to increase the T4+/T8+ ratio in vivo. Furthermore, peripheral blood mononuclear cells (PBMC) from young healthy volunteers who received intravenous papaverine (3 mg/kg i.v. over 15 min) showed a decreased response in allogenic mixed lymphocyte reaction (MLR) but a normal behaviour in a polyclonal mitogen assay and in autologous MLR (AMLR). These findings suggest that papaverine administration could influence the immune system functions.