VEGF-induced angiogenesis drives collateral circulation in portal hypertension

Portal hypertension is an increase in blood pressure within the portal venous system. Normally, this pressure is less than 5 mmHg. It is considered clinically significant when it rises above 10 mmHg. At this threshold, complications from altered blood flow and venous congestion emerge.EtiologyPortal hypertension arises from conditions that impede blood flow through the liver. The most common cause is cirrhosis, in which chronic liver injury leads to fibrotic scarring. This fibrosis narrows or...

Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits.  Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...

Blood vessel formation starts early during embryonic development, around day 7. In the extraembryonic yolk sac, mesodermal precursor cells called hemangioblast proliferate and differentiate into angioblast. Angioblasts express vascular endothelial growth factor receptor 2 or VEGFR2, which binds VEGF-A, a proangiogenic factor, guiding blood vessel formation. VEGF signaling promotes angioblasts to form a blood island in the developing embryo. Angioblasts further differentiate, giving rise to...

Esophageal varices are dilated, tortuous veins which are found mainly in the submucosa of the lower esophagus but which may also appear higher up or extend into the stomach. They develop due to increased pressure in the portal venous system, often as a result of liver cirrhosis. This condition scars and damages the liver, impeding normal blood flow through the portal vein. To compensate, blood seeks alternative pathways, forming fragile new vessels (varices) in the esophagus and stomach. These...

Esophageal varices often manifest as gastrointestinal bleeding episodes, presenting symptoms like hematemesis (vomiting of blood), hematochezia (passing fresh blood via the rectum), and melena (black, tarry stools). Other signs can include weight loss, anorexia, abdominal discomfort, jaundice, pruritus, altered mental status, and muscle cramps.
In the initial assessment, a thorough review of the patient's medical history is vital to identify risk factors such as liver disease, alcohol abuse, or...