ductus arteriosus closure

Definition

Target type: biologicalprocess

The morphogenesis process in which the ductus arteriosus changes to no longer permit blood flow after birth. The ductus arteriosus is the shunt between the aorta and the pulmonary artery which allows blood to bypass the fetus' lungs. [GOC:hw]

The ductus arteriosus, a blood vessel connecting the aorta and pulmonary artery in the fetal heart, is essential for fetal circulation. After birth, with the initiation of pulmonary respiration, the ductus arteriosus undergoes a physiological closure. This process involves a complex interplay of various factors:

**1. Oxygen Increase:** Birth marks a drastic increase in blood oxygen levels. This triggers a decrease in the production of prostaglandins, potent vasodilators that keep the ductus arteriosus open.

**2. Reduced Prostaglandin Levels:** The decrease in prostaglandin production, particularly prostaglandin E2, leads to vasoconstriction of the ductus arteriosus.

**3. Smooth Muscle Contraction:** Decreasing prostaglandins and increasing oxygen levels directly stimulate the smooth muscle cells in the wall of the ductus arteriosus to contract, further constricting the vessel.

**4. Intimal Thickening:** Following vasoconstriction, the inner lining of the ductus arteriosus, the intima, begins to thicken, further restricting blood flow.

**5. Fibrotic Closure:** Over time, the ductus arteriosus undergoes fibrosis, a process where fibrous connective tissue replaces the smooth muscle. This fibrosis results in the permanent closure of the ductus arteriosus, typically within a few days or weeks after birth.

**6. Contribution of Other Factors:** Other factors, including increased circulating levels of oxygen, thromboxane A2 (a vasoconstrictor), and nitric oxide (a vasodilator), also play a role in the complex process of ductus arteriosus closure.'
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Proteins (1)

Compounds (5)