Maternal-pup interaction disturbances induce long-lasting changes in the newborn rat pulmonary vasculature

Area of Science:

• Physiology
• Neonatology
• Vascular Biology

Background:

• Pulmonary vascular resistance can remain high postnatally due to unknown factors.
• Neonatal stressors are implicated in long-term vascular and behavioral changes.
• Cross-fostering is a model to study the impact of early-life stress.

Purpose of the Study:

• To investigate if fostering newborn rats leads to persistent pulmonary vascular changes into adulthood.
• To compare pulmonary vascular function and structure in fostered rats versus those raised by biological mothers.

Main Methods:

• Rats were cross-fostered or raised by biological mothers.
• Pulmonary vascular function was assessed at 14 days of age (adulthood).
• Evaluations included endothelium-dependent relaxation, gene expression (e.g., nitric oxide synthase, ANG II receptor type 1), and vascular remodeling.

Main Results:

• Fostered rats had reduced maternal-pup contact and impaired pulmonary arterial relaxation.
• Downregulation of endothelial nitric oxide synthase and tetrahydrobiopterin deficiency were observed.
• Increased ANG II receptor type 1 expression, pulmonary vascular remodeling, and right ventricular hypertrophy persisted into adulthood.
• Adult fostered rats showed heightened pulmonary artery contraction to ANG II and thromboxane A2.

Conclusions:

• Fostering-induced neonatal stress results in enduring pulmonary vascular alterations.
• These changes are mediated through the renin-angiotensin system.
• Early-life stress impacts long-term cardiovascular health.