Lanthanum inhibits surfactant secretion stimulated by lung distension in newborn rabbits.
The effect of lanthanum on lung phospholipid secretion stimulated by lung distension was examined in 29.5-d gestation newborn rabbits. Lung lavage with saline alone produced 608 +/- 109 micrograms phospholipid/lung (mean +/- SEM), whereas lavage with 10(-3) M lanthanum produced only 153 +/- 40 micrograms phospholipid/lung (p less than 0.05), the difference in yield being attributed to inhibited lavage-induced secretion with lanthanum. If this interpretation is correct, then an increased residual tissue surfactant should be found in lanthanum-lavaged lungs. Postlavaged lung was separated into IA, IB, and IC fractions by homogenization and then centrifugation with 0.25 and 0.65 M sucrose. The surfactant IB fraction was 763 +/- 65 micrograms phospholipid/g wet lung for saline-lavaged lungs, but 1002 +/- 90 micrograms phospholipid/g wet lung for lanthanum-lavaged lungs (p less than 0.002). This confirms that decreased secretion with lanthanum was associated with increased residual surfactant in postlavaged lung. It is concluded that lanthanum is a potent inhibitor of surfactant secretion stimulated by lung distension.
Corbet
A
A
Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030.
Owens
M
M
D000818:Animals; D000831:Animals, Newborn; D007811:Lanthanum / Q000494:pharmacology*; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D010743:Phospholipids / Q000302:isolation & purification*; D011663:Pulmonary Surfactants / Q000378:metabolism*; D011817:Rabbits; D007507:Therapeutic Irrigation
D010743:Phospholipids; D011663:Pulmonary Surfactants; D007811:Lanthanum