Adrenal influences on the inhibitory effects of procaterol, a selective Beta-two-adrenoceptor agonist, on antigen-induced airway microvascular leakage and bronchoconstriction in Guinea pigs

摘要: While the guinea pig has been preferred choice for use as a model of allergic bronchial asthma in evaluation anti-asthmatic drugs, it shown that antigen-induced bronchoconstriction pigs is attenuated by epinephrine released from adrenal gland. In order to investigate possible influence gland on effects antiexudative and bronchodilative drugs airway responses, we examined inhibitory procaterol, selective beta(2)-adrenoceptor agonist, microvascular leakage adrenalectomized compared them with drug's sham-operated animals. Guinea sensitized passively anti-ovalbumin (OA) guinea-pig serum were or under urethane anesthesia 30 min after surgery following experiments. (1) Animals intravenously administered Evans blue dye quantify plasma exudation, then OA was inhaled 10 while measuring pulmonary inflation pressure, parameter bronchoconstriction. Procaterol (1, 3, 10, microg/kg) saline (control) into airways prior inhalation. The amount extravasated calculated. (2) Venous blood samples collected during inhalation catecholamine levels compared. control animals, OA-induced increases both pressure markedly greater animals than dose-dependently inhibited bronchoconstriction, its more potent (significant at 1 microg/kg higher) higher). Although concentration approximately 3 times higher no difference seen conclusion, procaterol essentially possesses pronounced pigs, are considerably masked