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Polyunsaturated fatty acids and protection of newborn rats from oxygen toxicity
I R Sosenko1, S M Innis, L Frank
1Division of Neonatology, University of Miami School of Medicine, FL 33101.
Insights
High polyunsaturated fatty acids (PUFA) in newborn rat lungs improved survival during oxygen toxicity. Increasing lung PUFA content via maternal diet or milk transfer protected against hyperoxia, suggesting a key role for PUFA in neonatal lung defense.
Area of Science:
- Neonatal Physiology
- Nutritional Biochemistry
- Environmental Toxicology
Background:
- Oxygen toxicity poses a significant risk to newborn animals.
- The role of dietary polyunsaturated fatty acids (PUFA) in mitigating oxygen toxicity in neonates is not fully understood.
Purpose of the Study:
- To investigate the association between maternal diet, lung polyunsaturated fatty acid (PUFA) content, and protection against oxygen toxicity in newborn rats.
Main Methods:
- Two series of experiments were conducted using rat models.
- Maternal diets varied in PUFA content (high, low, regular) before and during gestation and lactation.
- Offspring lung lipid fatty acid composition and survival rates under hyperoxia (>95% oxygen) were assessed.
Main Results:
- Offspring from dams fed high-PUFA diets exhibited increased lung linoleic and arachidonic acids and a higher PUFA/saturated fatty acid ratio.
- High-PUFA diet offspring showed significantly improved survival rates (95%) compared to regular-diet (67%) and low-PUFA diet (45%) offspring under hyperoxia.
- Postnatal milk transfer of high PUFA to low-PUFA offspring rapidly enhanced lung PUFA and improved hyperoxic survival.
Conclusions:
- Increased lung polyunsaturated fatty acid (PUFA) content confers a protective effect against hyperoxia in newborn animals.
- Maternal diet and postnatal nutrition play a critical role in modulating neonatal lung defense against oxygen toxicity.
- Targeting PUFA levels may offer a strategy to enhance neonatal resilience to oxidative stress.
Abstract:
To test whether polyunsaturated fatty acids (PUFA) might be associated with protection against oxygen toxicity in newborn experimental animals, we performed two series of experiments. In the first series, adult female rats were fed one of three diets--regular Rat Chow, a high-PUFA (safflower oil-based) diet, or a low-PUFA (palm oil-based) diet--for several weeks before and throughout pregnancy and lactation. Newborn offspring of the three diet groups had similar antioxidant enzyme activities and surfactant development. Offspring of dams fed the high-PUFA diet had total lung lipid fatty acids characterized by increased linoleic acid (18:2 omega 6) and arachidonic acid (20:4 omega 6) and a significantly increased PUFA/saturated fatty acid ratio, compared with offspring of dams fed the regular diet or low-PUFA diet; associated with this increased PUFA pattern was markedly superior survival (80 of 84 (95%) vs 56 of 84 (67%) for regular-diet offspring, P less than 0.01) after 7 days in greater than 95% oxygen. Conversely, offspring born to dams fed the low-PUFA diet had decreased lung PUFA content and inferior tolerance to prolonged high O2 exposure (survival 38 of 84 (45%)). In the second experimental series, the postnatal provision of high PUFA rat milk to offspring born to dams fed the low-PUFA diet (via "cross-nurturing" by high-PUFA diet dams) rapidly increased their lung lipid PUFA and improved their hyperoxic survival (44 of 50 vs 25 of 50 for low-PUFA diet newborn animals kept with their low-PUFA mother rats, P less than 0.01). These studies suggest that increasing lung lipid PUFA can confer a protective effect against the toxic effects of hyperoxia on the newborn animal lung.