Bronchodilator Inhalation During Ex Vivo Lung Perfusion Improves Posttransplant Graft Function After Warm Ischemia.

BACKGROUND: We hypothesized that an injured lung graft from donation after cardiac death donors could be reconditioned before transplantation using an ex vivo lung perfusion (EVLP) system and ventilation with high-dose short-acting ß2-adrenergic receptor agonists. METHODS: Cardiac arrest was induced in a canine model by intravenous potassium chloride injection. Lungs were randomly assigned to two groups after 150 minutes of warm ischemia: inhalation of 1,400 µg of procaterol (BETA group, n = 5) or control group receiving solvent (CON group, n = 5) during EVLP. Left lungs were transplanted after 120 minutes of EVLP. Functional variables, tissue adenosine 5'-triphosphate levels, and tissue cyclic adenosine monophosphate levels were measured 240 minutes after transplantation. RESULTS: Physiologic pulmonary function was similar at the end of EVLP in both groups. However, significantly better graft oxygenation, dynamic pulmonary compliance, and reduced pulmonary vascular resistance were observed in the BETA group than in the CON group 240 minutes after transplantation. No severe adverse effects were observed after lung transplantation in the BETA group. Lung tissue adenosine 5'-triphosphate levels and cyclic adenosine monophosphate levels were significantly higher in the BETA group than in the CON group at the end of EVLP and at 240 minutes after transplantation. CONCLUSIONS: High-dose nebulized procaterol during EVLP ameliorated lung graft dysfunction at the early posttransplantation period without severe adverse effects. These data suggest that lung reconditioning with procaterol ventilation during EVLP improves lung graft function after transplantation.

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.

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