Encyclopaedia
to blood

Hemoglobin (from grech. haima - blood and an armour. globus - a sphere) - difficult ferriferous fiber eritrotsitov animals and the person, capable reversible to contact oxygen, providing its carrying over to fabrics.
the main function of haemoglobin consists in transport of respiratory gases. In capillaries of lungs in the conditions of surplus of oxygen last incorporates to haemoglobin. Blood current eritrotsity, containing molecules of haemoglobin with the connected oxygen, are delivered to bodies and fabrics where it is not enough oxygen, here necessary for course of oxidising processes oxygen is released from communication with haemoglobin. Besides, haemoglobin is capable to connect in fabrics a small amount dioksida carbon (CO2) and to release it in lungs. monooksid carbon (CO) oxygen, forming metgemoglobin (metHb, from meta … and haemoglobin, differently gemiglobin or ferrigemoglobin) contacts haemoglobin of blood more strongly, than. Thus, it is blocked processes of transportation of oxygen. In metgemoglobine iron gema is in a complex or in a trivalent status.
the normal maintenance of haemoglobin in blood of the person considers: at men 130-170 g/l, at women 120-150 g/l; at children - 120-140 g/l.
Hemoglobin is difficult fiber of a class hromoproteinov, that is in quality prosteticheskoj groups the special pigmentary group containing a chemical element iron - gem here acts.

the haemoglobin Molecule consists of four polipeptidnyh chains, each of which nekovalentno is connected with ferroprotoporfirinom (gem).

Hemoglobin is one of the basic fibers whom eat plazmodii a malaria, and in endemichnyh on a malaria globe areas hereditary anomalies of a structure of the haemoglobin, complicating malarial plazmodijam a food by this fiber and penetration in eritrotsit are rather extended. In particular, the is crescent-cellular anaemia concerns such anomalies having evoljutsionno-adaptive value. However, unfortunately, these anomalies, as well as anomalies of a structure of haemoglobin not imejushie obviously adaptive value, are accompanied by infringement oxygen-transporting of function of haemoglobin, stability decrease eritrotsitov to destruction, an anaemia and other negative consequences. Anomalies of a structure of haemoglobin are called gemoglobinopatijami.

Hemoglobin is highly toxic at hit of its considerable quantity from eritrotsitov in blood plasma (that occurs at massive intravascular gemolize, gemorragicheskom a shock, gemoliticheskih anemias, transfusion of incompatible blood and other pathological statuses). Toxicity of the haemoglobin which is out of eritrotsitov, in a free status in blood plasma, is shown fabric gipoksiej - deterioration of oxygen supply of fabrics, an overload of an organism by products of destruction of haemoglobin - iron, bilirubin, porfirinami with development of a jaundice or sharp porfirii, corking nephritic kanaltsev large molecules of haemoglobin with development nekroza nephritic kanaltsev and sharp nephritic insufficiency.

in view of high toxicity of free haemoglobin in an organism there are special systems for its linkage and neutralisation. In particular, one of components of system of neutralisation of haemoglobin is special plasma fiber gaptoglobin, specifically connecting free globin and globin as a part of haemoglobin. The complex gaptoglobina and globina (or haemoglobin) then is grasped by a spleen and macrophages fabric retikulo-endotelialnoj systems and neutralised.

Other part gemoglobinoobezvrezhivajushchej systems is fiber gemopeksin, specifically connecting free gem and gem as a part of haemoglobin. The complex gema (or haemoglobin) and gemopeksina then is grasped by a liver, gem otshchepljaetsja and used for synthesis of bilirubin and other bilious pigments, or is issued in retsirkuljatsiju in a complex with transferrinom for a reuse by a bone brain in process eritropoeza.