Human chorionic gonadotrophin: a chemoattractant for human blood monocytes, neutrophils and lymphocytes.

Treatment of rats with human chorionic gonadotrophin (hCG) induced in the testes an inflammation-like reaction characterized by migration of leukocytes into the interstitial space. In order to find out whether hCG acts in a direct manner in this process, we tested peripheral human blood leukocyte attraction by hCG in vitro. Chemotaxis through cellulose nitrate to gradients of test substances was measured using a 48-well microchemotaxis chamber. Human CG was found to be a potent attractor of neutrophils, monocytes and lymphocytes in vitro in the picomolar concentration range. Checkerboard analyses revealed that the type of migration depends on positive concentration gradients of hCG. The chemoattractant nature of hCG is consistent with its having a role to play in regulation of tissue accumulation of these cells within the reproductive tract.