Factors that influence the distention of immature lung with artificial surfactant.
The exogenous therapy of respiratory distress syndrome with artificial surfactants is controversial. In the present work we treated premature rabbits with artificial ultrasonic obtained surfactant suspensions [dipalmitoyldiphosphatidylcholine:dipalmitoyldiphosphatidylglyc erol (DPPC:DPPG) 7:3] in various physical conditions produced by changing the carrier (saline solution and amniotic fluid) or incubating at 41 degrees C. Nonincubated samples (S0) were nonactive, the best effect on alveolar distention being found after 8 h incubation (S8), while 16 h incubated samples (S16) were less effective. Liposomal size of the mixtures correlated with their effectiveness; small unilamellar liposomes were nonactive, large unilamellar ones were active and in presence of large multilamellar liposomes the tensioactive effect decreased. Fifty-one percent of the alveolar distention, evaluated by morphometry, was due to treatment and 11% was linearly related to body weight. The ponderal effect of body weight was mathematically excluded in order to obtain more uniform results; the resulting parameter was called true treatment influence on alveolar distention (TIAD). 15% of TIAD varied due to the carrier, with significantly better results when saline solution was used as a carrier. These findings question the hypothesis of the prevention of respiratory distress syndrome by means of intraamniotic injection of surfactants.
Ferrer-Roca
O
O
Department of Pathology, Faculty of Medicine, University of La Laguna, Tenerife, Spain.
Padilla
M C
MC
Domenech
E
E
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001835:Body Weight; D004337:Drug Carriers; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D010715:Phosphatidylglycerols / Q000494:pharmacology; D011663:Pulmonary Surfactants / Q000494:pharmacology*; D011817:Rabbits; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy* / Q000503:physiopathology
D004337:Drug Carriers; D010715:Phosphatidylglycerols; D011663:Pulmonary Surfactants; D015060:1,2-Dipalmitoylphosphatidylcholine; C030345:1,2-dipalmitoylphosphatidylglycerol