What Is the Renin-Angiotensin System?

The renin-angiotensin system (RAS) is an important body fluid regulating system composed of a series of peptide hormones and corresponding enzymes. Its main function is to regulate and maintain the balance of human blood pressure, water and electrolytes, and maintain the relative stability of the human body environment. The renin-angiotensin system is an important mechanism involved in the pathogenesis of hypertension under pathological conditions.

Basic Information

Chinese name

Renin-angiotensin system

Foreign name

RAS

Location

Circulatory system and blood vessel wall, heart, center, etc.

Clinical significance

Maintain the relative stability of the human body environment

Components and functions of renin-angiotensin system

1. The renin-angiotensin system exists in both the circulatory system and the vascular wall, heart, center, kidney, and adrenal glands. The renin-angiotensin system components mainly include renin, angiotensin-converting enzyme (ACE), angiotensinogen and angiotensin , myocardium, vascular smooth muscle, skeletal muscle, brain, kidney, gonadal and other organs and tissues Both are rich in angiotensin converting enzyme and angiotensin II receptor. In addition to the systemic renin-angiotensin system, there are relatively independent local renin-angiotensin systems in cardiovascular and other organs and tissues. This local renin-angiotensin system can pass paracrine and / or Autocrine mode regulates cardiovascular activity more directly and more importantly.
2. Renin secreted by the cells near the glomerulus can convert angiotensinogen in the blood into angiotensin I with no physiological activity. Angiotensin I forms an angiotensin 8 peptide under the action of angiotensin converting enzyme. Angiotensin III of the II and 7 peptides. Angiotensin plays a significant role in maintaining the body's blood pressure and blood volume balance, especially angiotensin , which has the strongest activity. It can contract the smooth muscle of small arteries throughout the body and promote the release of vasopressin and oxytocin by the pituitary gland, which strongly stimulates the adrenal cortex. Secretion of aldosterone, promotion of renal tubular reabsorption of water, sodium, excitement of sympathetic nerves and other mechanisms to increase hypertension, is currently the most effective booster substance known.
3. The local renin-angiotensin system effect in the heart is mainly the positive inotropic effect on the heart, which causes myocardial hypertrophy, regulates coronary artery resistance, and inhibits myocardial cell growth. The role of the local renin-angiotensin system in blood vessels is to relax and contract blood vessels, affecting the structure of blood vessels and the function of the coagulation system.

Clinical significance of renin-angiotensin system

The renin-angiotensin system has a variety of dual regulatory effects and the homeostasis regulatory function inside and outside the system, which can both promote tissue reconstruction and have anti-pathological reconstruction effects. It not only plays an important role in diseases such as hypertension, kidney disease, myocardial hypertrophy, but also has important pathological effects in almost all heart and cerebrovascular diseases. The excessive activation of the renin-angiotensin-aldosterone system is one of the causes of hypertension. The drugs that can inhibit the renin-angiotensin system mainly include the following.
Angiotensin-converting enzyme inhibitor (ACEI)
Angiotensin-converting enzyme inhibitors can inhibit angiotensin-converting enzyme activity, reduce angiotensin II production, and commonly used drugs such as captopril.
2. Angiotensin II receptor blockers Angiotensin II receptor blockers can block the binding of angiotensin II to angiotensin type 1 receptor (AT1 receptor), commonly used drugs such as sartan .
3. Renin inhibitors Renin inhibitors can inhibit the synthesis and release of renin and prevent the activation of the renin-angiotensin system.