[Effect of corticosteroids on tachyphylaxis induced by beta-2- receptor agonists in patients with bronchial asthma]

Fourteen patients with moderate bronchial asthma were selected for the study. Asthmatics were treated with intravenous salbutamol for one week. Peripheral blood lymphocyte beta-2-adrenergic receptor density and affinity were determined before and after the treatment. To investigate an effect of corticosteroids on beta-2-agonist induced desensitization of beta-2-receptors, beta-2-receptor density and affinity following prednisone administration have been determined in lymphocytes in 7 asthmatics. Patients have been given prednisone in the dose of 20 mg daily for 1 wk after salbutamol discontinuation. Spontaneous recovery of beta-2-adrenergic receptor density in the lymphocytes was estimated in further 7 asthmatics, not given corticosteroids following salbutamol therapy. Our data showed that down-regulation of beta-2-adrenergic receptors improves spontaneously and to significantly higher degree after corticosteroid therapy.