| Abstract: | The effects of IV histamine infusion and beta-adrenergic blockade on pulmonary function were studied in neonatal Holstein calves, beta-Adrenergic blockade with IV propranolol increased total pulmonary resistance, but was without effect on lung compliance, lung volumes, and gas exchange. beta-Adrenergic blockade enhanced the histamine-induced increase in total pulmonary resistance and the decrease in dynamic and quasistatic compliance, lung volumes, and arterial oxygen tension. These data indicate that beta-adrenergic receptors may be present in the large and small airways of cattle and they modulate the effects of bronchoconstrictor agents as in other species. |
