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Developmental changes in lung cGMP phosphodiesterase-5 activity, protein, and message
K A Hanson1, F Burns, S D Rybalkin
1Department of Pediatrics, Department of Anesthesiology, and Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington, USA.
Summary
Pulmonary phosphodiesterase type 5 (PDE5) levels decrease after birth, correlating with reduced pulmonary vascular resistance. A later increase suggests complex regulation, potentially informing treatments for pulmonary hypertension.
Area of Science:
- Cardiovascular Physiology
- Developmental Biology
- Pharmacology
Background:
- The transition from fetal to neonatal circulation involves significant pulmonary vascular remodeling.
- 3',5'-cyclic guanylate monophosphate (cGMP) regulates pulmonary vascular resistance (PVR) and vascular smooth muscle (VSM) proliferation.
- cGMP hydrolysis is primarily mediated by cGMP-specific phosphodiesterases (PDEs), with PDE5 being abundant in lung tissue.
Purpose of the Study:
- To investigate the expression and activity of pulmonary PDE5 during perinatal development in ovine and mouse models.
- To understand the role of PDE5 in regulating pulmonary vascular tone and VSM content during the critical transition after birth.
Main Methods:
- Quantification of PDE5 enzymatic activity, protein levels, and messenger RNA (mRNA) in lung tissue.
- Comparative analysis between ovine and mouse models during perinatal development.
Main Results:
- Pulmonary PDE5 activity, protein, and mRNA levels significantly decreased within 1 hour after birth in both species.
- These early decreases correlated with established reductions in PVR during the neonatal transition.
- A secondary rise in PDE5 expression and activity was observed between 4 to 7 days postpartum, indicating complex regulation.
Conclusions:
- Pulmonary PDE5 plays a dynamic role in regulating PVR during perinatal development.
- The biphasic regulation of PDE5 suggests its involvement in both early adaptation and later developmental processes.
- Findings support PDE5 as a potential therapeutic target for pulmonary hypertension and related vascular disorders.