Characterization of the beta receptor responsible for enhanced histamine release from bovine leukocytes

The present study was undertaken to determine the beta-receptor subtype responsible for the enhanced anaphylactic histamine release from bovine leukocytes produced by isoprenaline. The selective beta 1 antagonist practolol competitively inhibited the enhancement of histamine release produced by isoprenaline. The selective beta 2 agonists salbutamol and terbutaline produce no significant effect on antigen-induced histamine release. This indicates that the receptor responsible for enhancement of histamine release from bovine granulocytes is of the beta 1 subtype. The question is raised as to whether this is a normal physiological response or an abnormal condition produced by the sensitization procedure.