Adrenergic activity on rat pleural and peritoneal mast cells. Loss of beta-receptors during the purification procedure.

Adrenergic agonists inhibit the release of histamine from rat pleural and peritoneal mast cells stimulated with compound 48/80 to a degree dependent on their beta-activity. Isoprenaline takes part in a stereoselective inhibitory action in the range 10(-7)-10(-4) M. Adrenaline induces a similar response pattern, with inhibition at higher concentrations. The response profile, but not the maximum values of inhibition, is clearly dependent on the concentration of the histamine releaser. Noradrenaline by itself is a histamine releaser, no stereoselectivity being observed. In the presence of compound 48/80 it takes part in a non-stereoselective inhibitory reaction at low concentrations. Inhibition of histamine release by isoprenaline was antagonized by 10 or 100 microM propranolol except at the highest isoprenaline concentration (1 mM). Both atenolol and propranolol nullified the inhibitory activity of noradrenaline, but not the increased histamine release it induces at higher concentrations (at least when acting in conjunction with compound 48/80). When rat mast cells are purified through Percoll, a change in their response profiles is observed. Isoprenaline and adrenaline by themselves elicit non-specific release of histamine; with compound 48/80, release is additive in the case of isoprenaline and supra-additive in the case of adrenaline. Results point to the loss of beta-adrenergic inhibitory activity after purification.