Perinatal pulmonary prostaglandin production

Area of Science:

• Cardiovascular Physiology
• Neonatal Physiology
• Prostaglandin Biology

Background:

• Prostaglandins (PGs) and thromboxanes are key mediators in cardiovascular regulation.
• Pulmonary vascular resistance must decrease significantly for successful transition from fetal to neonatal circulation.
• The role of PGs in fetal lung adaptation to air breathing is not fully understood.

Purpose of the Study:

• To investigate the impact of ventilation on prostaglandin production in fetal lungs.
• To determine the specific role of PGI2 in mediating the decrease in pulmonary vascular resistance after birth.

Main Methods:

• Analysis of prostaglandin and thromboxane products using gas chromatography with electron-capture detection.
• Measurement of venous effluents from Krebs-perfused fetal goat and sheep lungs before and after air ventilation.
• Assessment of pulmonary vascular resistance changes post-ventilation.

Main Results:

• Ventilation significantly decreased pulmonary vascular resistance.
• Lung production of 6-keto-PGF1 alpha and its metabolite increased by 50% and 230% after ventilation, respectively.
• Increased PGI2 synthesis was observed, particularly in pulmonary resistance vessels.

Conclusions:

• Ventilation of fetal lungs with air stimulates PGI2 synthesis.
• PGI2 plays a critical role in reducing pulmonary vascular resistance during perinatal transition.
• These findings support the hypothesis that PGI2 is essential for successful adaptation to air breathing at birth.