Stimulation of Surfactant Production by Oxytocin-Induced Labor in the Rabbit

Rooney, Seamus A.; Gobran, Laurice I.; Wai-Lee, Theresa S.

doi:10.1172/jci108828

Cited by 62 publications

(21 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The developmental increase in the activity of this enzyme in rat lung cytosol parallels the increase in phospholipids in the same fraction (72 (68,133) and mouse (65) lung. There is a postnatal increase in the activity of CPT in the rabbit (70,71,81) while in the rat adult activities are considerably higher than those of the fetus or newborn (68,133). In two studies, however, the activity of lung CPT was reported to peak 1 to 2 days before term in the rat (67,135) and mouse (69).…”

Section: Enzymes Of Phospholipid Synthesismentioning

confidence: 93%

“…Birthandlaborhavebeenreported to stimulate surfactant production. There was a 2-to 4-fold increase in the phospholipid content of lung lavage from newborn rabbits delivered by cesarean section prior to labor at 29-31 days gestation (70,194). A similar finding was reported by Lawson et al.…”

Section: Other Factors Which Influence Surfactant Production In the Fmentioning

confidence: 98%

“…There is a developmental increase in the activity of CP-CYT either at the end of gestation or immediately after birth in the rabbit (70,71), rat (66)(67)(68)72) and mouse (65,69) lung. Fetal lung CP-CYT activity is stimulated up to 7-fold by phosphatidylglycerol in the rat (136), rabbit (76) and mouse (65).…”

Section: Enzymes Of Phospholipid Synthesismentioning

confidence: 99%

“…Recent studies have shown that labor increases the L/S ratio and PC content of human amniotic fluid (201,(313)(314)(315). Animal studies have also shown that labor increases surfactant production (70,199). Studies with newborn rabbit lung slices showed that labor stimulated surfactant secretion rather than synthesis (199).…”

Section: Other Factors Which Influence Surfactant Production In the Fmentioning

confidence: 99%

See 3 more Smart Citations

Lung surfactant.

Rooney¹

1984

Environ Health Perspect

View full text Add to dashboard Cite

Aspects of pulmonary surfactant are reviewed from a biochemical perspective. The major emphasis is on the lipid components of surfactant. Topics reviewed include surfactant composition, cellular and subcellular sites as well as pathways of biosynthesis of phosphatidylcholine, disaturated phosphatidylcholine and phosphatidylglycerol. The surfactant system in the developing fetus and neonate is considered in terms of phospholipid content and composition, rates of precursor incorporation, activities of individual enzymes of phospholipid synthesis and glycogen content and metabolism. The influence of the following hormones and other factors on lung maturation and surfactant production is discussed: glucocorticoids, thyroid hormone, estrogen, prolactin, cyclic AMP, p-adrenergic and cholinergic agonists, prostaglandins and growth factors. The influence of maternal diabetes, fetal sex, stress and labor are also considered. Nonphysiologic and toxic agents which influence surfactant in the fetus, newborn and adult are reviewed.

show abstract

Section: Enzymes Of Phospholipid Synthesismentioning

confidence: 93%

Section: Other Factors Which Influence Surfactant Production In the Fmentioning

confidence: 98%

Section: Enzymes Of Phospholipid Synthesismentioning

confidence: 99%

Section: Other Factors Which Influence Surfactant Production In the Fmentioning

confidence: 99%

See 2 more Smart Citations

Lung surfactant.

Rooney¹

1984

Environ Health Perspect

View full text Add to dashboard Cite

show abstract

“…Studies with newborn rabbits have shown that the percent of acetone precipitable lecithin in pulmonary lavage (12), pulmonary stability (29), and pulmonary lavage phospholipid content (25) increase after birth. These findings indicate that immediately after birth the secretion of surfactant into the alveoli is increased over and above the fetal secretion rate.…”

Section: Speculationmentioning

confidence: 99%

Augmentation of Pulmonary Surfactant Secretion by Lung Expansion at Birth

et al. 1979

Pediatr Res

View full text Add to dashboard Cite

SummaryTo study the effect of lung expansion at birth on surfactant secretion, we delivered by hysterotomy 11 litters of rabbit pups at 30 days of gestation and divided them into three groups that were killed: 1) after 30 min air-breathing, 2) after 30 min nitrogenbreathing, and 3) after 30 min tracheal occlusion. Each group was compared to a littermate group killed at birth. Groups 2) and 3) continued respiratory efforts for 30 min despite progressive asphyxia. Six additional litters were pretreated with atropine; at delivery one-half of each litter was killed, the remaining pups were subjected to 30 min of hypoxic gas breathing. After sacrifice, alveolar surfactant was recovered by saline lavage and estimated quantitatively on a surface-tension balance. Surfactant concentration at birth was 1.40 + 0.22 mg/g dry lung and increased to 1.86 f 0.19 (k SEM) after 30 min air-breathing (P < 0.01). Also, surfactant was increased in the nitrogen-breathing pups (from 1.61 , f 0.35 in littermate controls to 2.41 f 0.58, P < 0.03), but not to a significant degree in the occluded group (1.34 + 0.33 vs. 1.41 k 0.28), or the atropine pretreated breathing pups (1.77 + 0.29 vs. 1.89 + 0.25). SpeculationThe data indicate that lung expansion at birth enhances surfactant release from intracellular sites and suggest that the vagus nerve mediates this effect. It is possible that the effect of maternal atropine may have clinical significance in preterm infants.Studies with newborn rabbits have shown that the percent of acetone precipitable lecithin in pulmonary lavage (12), pulmonary stability (29), and pulmonary lavage phospholipid content (25) increase after birth. These findings indicate that immediately after birth the secretion of surfactant into the alveoli is increased over and above the fetal secretion rate. With the onset of breathing, augmented surfactant secretion may be due to mechanical, neuronal, or humoral factors. Both lower surface tension and increased saturated lecithin in alveolar wash result from constant air-expansion of excised adult dog lungs (8), a mechanical stimulus. In rabbits, fetal injection of pilocarpine or P-adrenergic stimulants (e.g., isoxsuprine) also result in increased alveolar surfactant (5,6,7,18,30). These pharmacologic effects suggest autonomic control of surfactant secretion.To determine the physiologic stimulus for increased alveolar surfactant after birth, we measured quantitatively the surfacebreathing and the occluded pups differentiate the effects of asphyxia with and without gas ventilation of the lungs. The findings in the atropine pretreated groups establish that neural factors mediate surfactant secretion at birth. MATERIALS AND METHODS ANIMAL PROCEDURESTwenty litters of New Zealand white rabbits were used. The gestation of each litter was known to be 30 days within 3 hr (term = 31 days). In 11 litters, the does were sacrificed immediately before laparotomy with an iv infusion of 300 mg pentobarbital. Within 2 min, all the pups of a litter were gently delivered within their amnioti...

show abstract

Lung Metabolism in the Fetus and Neonate

Zimmermann¹,

Golde²

1998

Principles of Perinatal—Neonatal Metabolism

View full text Add to dashboard Cite

Stimulation of Surfactant Production by Oxytocin-Induced Labor in the Rabbit

Cited by 62 publications

References 29 publications

Lung surfactant.

Lung surfactant.

Augmentation of Pulmonary Surfactant Secretion by Lung Expansion at Birth

Lung Metabolism in the Fetus and Neonate

Contact Info

Product

Resources

About