Mechanisms Underlying Vascular Endothelial Growth Factor Receptor Inhibition-Induced Hypertension: The HYPAZ Trial

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...

Hypertension is a chronic condition in which the blood's force against artery walls is excessively high, posing risks such as heart disease. The condition's underlying mechanisms involve complex interactions among the cardiovascular, kidney, and autonomic nervous systems.Renin-Angiotensin-Aldosterone System (RAAS): This system significantly influences blood pressure regulation. When blood pressure decreases, the kidneys secrete renin. This enzyme transforms angiotensinogen, a plasma protein,...

Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing...

In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth...

Endocrinal or hormonal intervention in the cardiovascular system is predominantly exerted by the catecholamines - epinephrine and norepinephrine, as well as a slew of hormones that interact with renal function to modulate blood volume.
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction...

The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,...