In vitro and in vivo effect of salbutamol on histamine release from human basophils

The effect of salbutamol, a selective beta 2-adrenergic agonist, on immunological release of histamine from leukocytes isolated from blood of 14 allergic, asthmatic patients, was investigated after in vivo or in vitro drug administration. Simultaneously, the effect of this drug on peak expiratory flow rate (PEFR) was estimated. Histamine was assayed by the single isotope-enzymatic method. Obtained results have confirmed that salbutamol is a rather poor inhibitor of histamine release from basophils. Although both administered salbutamol doses (0.5 or 1 mg, i.v.) significantly increased PEFR (p less than 0.01), inhibitory effect on histamine release by allergen was seen only after higher dose administration in vivo (p less than 0.01 against control). Similarly, a small but significant decrease in histamine release by both concanavalin A (by 20%, p less than 0.01) and allergen (by 30%, p less than 0.025) was seen in vitro after incubation of leukocytes with 8 x 10(-6) mol/l salbutamol, whereas 4 x 10(-7) mol/l salbutamol was without effect.