[Possible mechanisms of the action of lymphocyte proliferation-inhibitory factor(s) in rat serum receiving electroacupuncture stimulation].

Previous reports showed that EA stimulation (3V, 2Hz, 30 min/d, 5 d) induced the production of one or more lymphocyte proliferation-inhibitory factor(s) in the rat serum. In this paper, the mechanisms of the action for the inhibitory factor(s) to suppress lymphocyte proliferation were studied. (1) the lymphocytes from different immune organs of the mice were prepared and cultured with the rat serum stimulated by EA. The results show that the serum not only inhibited the mouse lymph node T cell proliferation induced by Con A, but also inhibited the mouse thymocyte and spleen T cell proliferation induced by Con A. When B cells were stimulated by LPS, the proliferative effect can also be inhibited significantly by the rat serum stimulated by EA. This implies that the effect of the lymphocyte proliferation-inhibitory factor(s) has no specificity. (2) Incubation of the mouse lymph node cell with serum for one hour is enough to cause an inhibitory effect on Con A stimulated lymphocyte proliferation. However, no inhibitory effect was observed if the mouse lymph node cells were incubated with Con A for 15 min or 30 min before the addition of rat serum. The results demonstrate that the lymphocyte proliferation-inhibitory factor(s) act on the early events of T lymphocyte activation induced by Con A. (3) Protein kinase C (PKC) is a key link in the activation of T and B lymphocyte proliferation by Con A and LPS respectively. So it would be interesting to learn whether the inhibitory effect of the lymphocyte proliferation-inhibitory factor(s) is caused by the inhibition of PKC activity.(ABSTRACT TRUNCATED AT 250 WORDS)