Drug

Angiotensin 2 effect

introduction

As part of the so-called renin-angiotensin-aldosterone system (RAAS for short), angiotensin 2 has a significant influence on the maintenance of many processes within the organism. Angiotensin 2 is a hormone produced by the body that belongs to the group of peptide hormones (Proteohormones) is counted.

All peptide hormones have in common that they are made up of small individual components, the amino acids, and can be easily dissolved in an aqueous environment. This means that all proteohormones are water-soluble (hydrophilic / lipophobic). Angiotensin 2 consists of a total of eight amino acids, two of which must be ingested in sufficient quantities through food (essential amino acids).

Due to its water-soluble property, angiotensin 2 Not capable of diffusion through the cell membrane to get. The tissue hormone can only function as a messenger after binding at one suitable surface receptor unfolded and exert an influence on organic cells.
As part of the renin-angiotensin-aldosterone system, angiotensin 2 plays a decisive role in the Regulation of

Water balance
Maintenance of kidney function and
Blood pressure

The activation of the renin-angiotensin-aldosterone system and thus also the formation of angiotensin 2 is carried out in the body special sensors in the kidney area triggered. The Kidneys respond to you falling blood pressure or one decreased tissue blood flow with the release of the enzyme Renin.

As an enzyme, renin is able to split off angiotensin 1, the precursor hormone formed in the liver cells. Angiotensin 1 represents the direct precursor of the active tissue hormone Angiotensin 2. The conversion of the hormone precursor to the active hormone takes place with the help of the so-called Angiotensin Converting Enzymes (short: ACE).

Effects of angiotensin 2

The renin-angiotensin-aldosterone system and its intermediate product angiotensin 2 are decisive in the organism Regulation of blood pressure and des Blood volume involved.

The most important task of this regulatory system consists above all in that Compensation for large volume losses and drops in blood pressure. The renin-angiotensin-aldosterone system is in a circulatory and volume-stable organism usually inactivated and the The formation of angiotensin 2 is suppressed.

Only with one acute drop in blood pressurewhich is registered by special kidney cells, the body stimulates the production of angiotensin 2. Angiotensin 2 is released from its precursor molecules over several steps and transported through the bloodstream.

Because of his water soluble properties However, the hormone is not able to reach its target cells freely through the cell membrane. In order for angiotensin 2 to be effective, it has to reach a specific receptor on the cell surface (AT receptor) tie. This surface receptor can mainly be found on the cell membranes of Blood vessel, kidney and adrenal cells Find.

After the binding of angiotensin 2 to the AT receptor smoother Muscle cells, becomes inside the target cell a Activation cascade triggeredwhich ultimately in the contraction (Tension) of the smooth vascular muscle cells opens. In this way, the previously dropped blood pressure increased again by the influence of the renin-angiotensin-aldosterone system and the tension in the vascular muscle cells.

In the kidney area, the activation of the specific angiotensin 2 receptor has one thing above all else Effect on the smallest kidney vessels. The smooth vascular muscle cells of the kidney also respond to the stimulus triggered by angiotensin 2 with a contraction. With the help of this process you can despite falling blood pressure a even kidney blood flow and thus a almost constant kidney function guaranteed.

In addition, the concentration of the tissue hormone angiotensin 2 also affects the Adrenal glands out. There, however, angiotensin 2 has no direct effect on the vessels and vascular muscle cells. Rather, the effect of the hormone is in this organ indirectly, by stimulating the release of further messenger substances (Aldosterone and adrenaline) mediated.

Also in the Pituitary gland (Pituitary gland) after angiotensin 2 binds to the specific cell surface receptor, an increased release of further hormones is stimulated. The effect of angiotensin 2 on the blood circulation and the individual organ systems is therefore far-reaching. It is precisely for this reason that the renin-angiotensin-aldosterone system and the hormone angiotensin 2 are used in the pharmaceutical industry important points of attack in the treatment of high blood pressure represent.

The common drugs that start in the area of the renin-angiotensin-aldosterone system are usually used Lowering high blood pressure (hypertension) used. These drugs are so-called Antihypertensive drugs. In addition to an inhibition of the angiotensin 2 synthesis, which ultimately becomes noticeable through a suppression of the hormone-specific effect, it is also possible to intervene at the level of the renin.

To the most relevant side effects of antihypertensive drugs include: