The effect of horse placental tissue extracts and equine chorionic gonadotrophin on the proliferation of horse lymphocytes stimulated in vitro.
Commercial preparations of equine chorionic gonadotrophin (eCG) and extracts of horse placenta taken at 80 days gestation were incorporated into mixed lymphocyte culture and mitogen stimulation assays of horse peripheral blood mononuclear cells. A dose-related inhibition of lymphocyte proliferation, indicative of immunosuppressive activity, was observed in both systems, both with commercial eCG preparations and tissue extracts. Negligible inhibitory activity was observed with an extract of term placenta. The inhibitory activity of the placental samples was not related to their eCG content as measured by immunoassay. The fact that one pregnant horn allantochorion extract containing 50 IU/ml of eCG showed an identical dose-dependent lymphoproliferation-inhibitory activity to an extract of a second such allantochorion containing only 1.7 IU/ml of eCG suggests that this hormone does not inhibit lymphocyte proliferation and that commercially available eCG contains inhibitory contaminants.
Lea
R G
RG
Department of Biomedical Sciences, Sheffield City Polytechnic, U.K.
Bolton
A E
AE
D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D006736:Horses / Q000276:immunology* / Q000378:metabolism; D007108:Immune Tolerance; D008213:Lymphocyte Activation / Q000187:drug effects*; D010920:Placenta / Q000737:chemistry / Q000276:immunology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000276:immunology; D014020:Tissue Extracts / Q000494:pharmacology
D006064:Gonadotropins, Equine; D014020:Tissue Extracts; D003208:Concanavalin A