The present study was designed to delineate the immunomodulatory role of histamine receptors (H1- and H2-) on induction of antibody response to sheep red blood cells (SRBC), as well as the antibody generation profile, in rabbit system, systemically. The rabbits in two groups received pheniramine (H1-receptor antagonist) and ranitidine (H2-receptor antagonist), respectively, via intramuscular route and were immunized with SRBC intravenously to evaluate suppression or enhancement of antibody responses in sem. A third, control group, received vehicle and were immunized in a similar manner. Histamine released from effector cells (mast cells and basophils) _in vivo_ during inflammatory reactions could influence a detectable antibody response to SRBC as early as... |