[Second messengers in the realization of immunomodulating effects of chorionic gonadotropin]

The mechanisms of the molecular action of chorionic gonadotropin (CG) at different doses have been studied in splenocyte culture on the level of secondary messengers. It has been demonstrated that in the dose of 40 IU CG suppresses the splenocyte ability to form plaque-forming cells (PFC) only in the presence of macrophages through the eicosanoid system. The dose of 200 IU produced an analogous effect using Ca2+ as the secondary messenger. Transduction of the hormonal signal, leading to immunosuppression does not depend on the inositide system. It is established that in a low dose CG selectively stimulates PFC formation on the condition that there are no macrophages in the cell culture. This effect depends on Ca2+ and inositol phosphates, which are synergists. The dose of 200 IU in the absence of macrophages does not show an immunomodulating effect. We propose the presence of high-affinity receptors for CG on macrophages an B-lymphocytes and low-affinity receptor on T-lymphocyte suppressors, which are associated with "slow" Ca2+ channels.