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Updated: Sep 8, 2026
A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis
Published on: January 7, 2018
Intrauterine growth-retarded rat pups show increased susceptibility to pulmonary O2 toxicity
Insights
Prenatal undernutrition in rat pups significantly reduces their survival in high oxygen environments. This is linked to decreased lung antioxidant enzymes and altered lung structure in intrauterine growth-retarded newborns.
Area of Science:
- Neonatal physiology
- Developmental biology
- Environmental toxicology
Background:
- Intrauterine growth retardation (IGR) is associated with altered development.
- Premature infants and those with IGR often exhibit increased vulnerability to environmental stressors.
- High oxygen (hyperoxia) exposure is a common neonatal intensive care unit (NICU) intervention with potential toxicity.
Purpose of the Study:
- To investigate the impact of prenatal nutritional deprivation on neonatal rat survival in hyperoxia.
- To identify lung-specific factors contributing to compromised hyperoxia tolerance in intrauterine growth-retarded (IGR) rat pups.
Main Methods:
- A nutritional deprivation model was used to induce intrauterine growth retardation (IGR) in rat pups.
- Survival rates and time to 50% mortality (LT50) were assessed during exposure to >95% oxygen.
- Lung biochemical and morphometric parameters were analyzed at birth and during oxygen exposure.
Main Results:
- IGR rat pups exhibited significantly reduced survival (21% vs. 50% for controls) and shorter LT50 (7.2 vs. 10 days) in hyperoxia (p<0.01).
- At birth, IGR pups showed decreased lung glutathione peroxidase and glucose-6-phosphate dehydrogenase activity, with normal superoxide dismutase and catalase.
- IGR newborns also had reduced lung disaturated phosphatidylcholine content and decreased lung surface area relative to body weight.
Conclusions:
- Prenatal undernutrition compromises neonatal survival in hyperoxia.
- Decreased antioxidant enzyme activity and altered lung composition in IGR pups likely contribute to their increased susceptibility to oxygen toxicity.
- These findings highlight the importance of nutritional status in neonatal adaptation to oxidative stress.
Abstract:
We used a nutritional deprivation model to produce intrauterine growth-retarded (IGR) rat pups (birth weight = approximately 75% of normal). The IGR newborns evidenced a marked reduction in tolerance to greater than 95% O2 exposure: 10-day survival = 10/47 (21%) versus 18/36 (50%) for control pups, and LT50 = 7.2 days versus 10 days for controls (p less than 0.01). Various lung parameters at birth and during O2 exposure were examined to try to define why prenatal undernutrition should compromise the survival of IGR rats in hyperoxia. We found decreased lung glutathione peroxidase and glucose-6-phosphate dehydrogenase activity (with normal superoxide dismutase and catalase levels) in the IGRs at birth; decreased lung disaturated phosphatidylcholine content (even more markedly decreased in 1-day premature pups); and decreased lung surface area/body weight. These factors and other features of newborn IGRs reported in the literature may help to explain how prenatal undernutrition compromises postnatal tolerance to prolonged high-O2 exposure.
