@entity859 and @entity4443 have a regulatory role in lung surfactant secretion in the newborn XXXX .

@entity859 @entity1439 @entity4443 @entity18412 @entity95 @entity2434 @entity14922 @entity4352 @entity2604 @entity35 @entity10271 @entity4291
Previous studies have shown that secretion of @entity2434 in cultured adult @entity35 type II pneumocytes is stimulated by purinoceptor agonists and @entity4443 . The objective of the present study was to determine if such agents have a physiological role in the regulation of surfactant secretion. We chose the newborn @entity95 as the experimental model, since in this system there is a marked increase in surfactant secretion immediately after birth. We examined the effects of an inhibitor of leukotriene biosynthesis, @entity2604 , two leukotriene antagonists, @entity1439 and @entity18412 , and a P1 purinoceptor antagonist, @entity14922 , on this increase. Newborn @entity95 were delivered by Cesarean section at 30 days gestation. Some animals in each litter were killed immediately, while others were injected with test agents or solvent vehicle while still in the amniotic sacs. After breathing for 3 h in an incubator, these animals were also killed. The lungs were lavaged with saline and the phospholipid content and composition of the lung lavage liquid was measured. In control animals, there was a greater than 2-fold increase in the amounts of total @entity10271 and @entity2434 and in the @entity2434 / @entity4291 ratio during the 3 h period of breathing. The increases in total phospholipid and @entity2434 were decreased 38-62% by the antagonists, while the increase in the @entity2434 / @entity4291 ratio was decreased 61-77%. These data show that the ventilation-induced increase in secretion of lung surfactant in the newborn @entity95 is inhibited by @entity4352 and P1 receptor antagonists and by an inhibitor of leukotriene biosynthesis and, when taken together with the data from the tissue culture system, support a role for @entity4443 and @entity859 in the physiological regulation of surfactant secretion.
