Pulmonary surfactant release in fetal rabbits as affected by terbutaline and aminophyllin.
Terbutaline; a beta2-adrenergic agonist, and aminophyllin, a phosphodiesterase inhibitor, were given separately, or in combination, to rabbit fetuses on the 28th day of gestation. The possibility of these drugs causing a release of pulmonary surfactant was evaluated 3 h after i.m. injection directly to the fetus. Lung compliance was studied and lung lavage fluid assessed as regards content to total phospholipid phosphorus, lecithin/sphingomyelin (L/S) ratio, and surface activity. It was found that terbutaline, in a dose of 0.1 mg, had a significant (p less then 0.05) effect on each of the four parameters studied and, when given in a dose of 0.05 mg, significantly affected all except L/S ratio. Aminophyllin, in a dose of 10 mg, resulted in a 40% mortality, but in the surviving fetuses the drug had no significant (p greater than 0.05) effect on any of the four parameters. When 5 mg aminophyllin was given together with 0.05 mg terbutaline, the effect could be attributed to terbutaline.
D000628:Aminophylline / Q000494:pharmacology*; D000818:Animals; D005260:Female; D005865:Gestational Age; D008168:Lung / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D011247:Pregnancy; D011663:Pulmonary Surfactants / Q000378:metabolism*; D011817:Rabbits; D013107:Sphingolipids / Q000378:metabolism; D013726:Terbutaline / Q000494:pharmacology*
D010713:Phosphatidylcholines; D010743:Phospholipids; D011663:Pulmonary Surfactants; D013107:Sphingolipids; D000628:Aminophylline; D010758:Phosphorus; D013726:Terbutaline