Possible mechanism of hydrocortisone induced eosinopoenia

Hydrocortisone (HC) injection in rabbits induced eosinopoenia (reduction in absolute eosinophil count) which could be successfully abolished by beta--adrenoceptor antagonists, a propranolol, sotalol, practolol and H 35/25 but not by alpha--adrenoceptor antagonist, phenoxybenzamine. Reserpine per se produced eosinopoenia followed by eosinophilia. However, reserpine pretreatment failed to abolish HC-induced eosinopoenia. It is suggested that the eosinopoenia is mediated through beta--adrenoceptors, which could not be differentiated into beta 1/beta 2--adrenoceptor subtypes as has been possible for other beta-adrenoceptor mediated responses.