Cause of nephrotic proteinuria

  Click:

Proteinuria is a typical symptom of chronic kidney disease, the causes of albuminuria and glomerular barrier function has a close relationship. Proteinuria, glomerular capillaries are composed of three layers, from the inside layer of endothelial cells, respectively, the base film and the epithelial cell layer. As the cells are distributed in three layers of filter pore sizes and negative charge, so the barrier function of glomerular capillary can be divided in two, the mechanical barrier – barrier filter holes and the charge – a negative charge.


There are three main mechanisms to cause proteinuria:

    Due to disease in glomerulus
    Because of increased quantity of proteins in serum (overflow proteinuria)
    Due to low reabsorbtion at proximal tubule (fanconi)

Proteinuria can also be caused by certain biological agents, such as bevacizumab (Avastin) used in cancer treatment.

1, the mechanical barrier – Scleral

Glomerular filtration barrier from the inside out by three components:

① Inner layer is the capillary endothelial cells. Endothelial cells have many small holes 50-100nm in diameter, called fenestrae (fenestration). Water, a variety of solutes and macromolecules can freely through the fenestrae of protein; but it prevents the blood cells through, playing the role of blood cell barrier.

② Middle of the base non-cellular membrane, was micro fiber network structure. Larger plasma molecules, such as basement membrane proteins cannot. Glomerular basement membrane is the filtration of protein molecules to prevent a major barrier.

③ Outer layer is the glomerular epithelial cells. Epithelial cells foot processes, cross-cutting fissure between the foot processes. Fissure cracks on a layer of membrane filtration (filtration slit membrane), membrane 4-14nm in diameter holes, which can prevent from the inside, the two proteins through the filter out of the macromolecules, is the final filtration barrier. Endothelial cells, basement membrane and the membrane constitute the fractured glomerular filtration membrane. Filtration membrane filtration channels of different sizes, so the small molecules can easily pass, the larger the effective radius of the material only through the larger channels, in general, the effective radius of less than 1.8nm material, can be completely filtered. Effective radius is larger than 3.6nm macromolecules, such as albumin (molecular weight of about 69,000) is almost totally filtered.

2, the charge barrier – the negative charge

Filtration membrane contains many layers of material with a negative charge, so the permeability of the membrane filtration is filtration material is also determined by the charge. The exclusion of the negatively charged material with negatively charged plasma proteins, limiting their filtration. Although the effective radius of serum albumin 3.5nm, but because of its negative charge, it is difficult through the filtration membrane. When a variety of pathological damage (including primary and secondary injury) on the kidneys, can cause partial damage to the kidney microcirculation, promote kidney (functional renal units) ischemia and hypoxia. Because ischemia, hypoxic injury of the glomerular capillary endothelial cells. Glomerular capillary endothelial cells, once damaged, it will attract circulating inflammatory cell infiltration, and release of inflammatory mediators of disease (IL-1, TNF – α, etc.) can cause pathological damage at this time impaired renal inflammatory response. Kidney in the pathological state, glomerular basement membrane (GBM) will be a series of changes: the increase or closed pore filtration, GBM fracture, the charge barrier damage, kidney permeability-increasing, negatively charged membrane filtration of sugar proteins decreased or disappeared, will lead to negatively charged than the normal plasma protein significantly increased filtration. Therefore, the formation of clinical proteinuria.

  • Print

You may also be interested in:

Discuss this Article

Click Here to see all comments
Please aware of self to obey the Internet related policy laws and strictly forbid to release porn, violence.
Appraisal:

Name:

Email:

Content:

Today's Picks

French and U.S. scientists recently discovered that broccoli is not only rich in vitamins and mineral content, and possibly even lead to gastric cancer, Helicobacter pylori kill the magic. At

Broccoli prevent stomach cancer

French and U.S. scientists recently discovered that broccoli is not only rich

Tuberculosis, also known as tuberculosis, young people prone to a chronic infectious disease. Throughout the year can be the disease, 15-year-old to 35-year-old youth is the high peak age of

Young people how to prevent tuberculosis?

Tuberculosis, also known as tuberculosis, young people prone to a chronic

Appendicitis commonly known as appendicitis. Cecal appendix is near the head of the worm-like blind prominent tube, located in right lower abdomen, appendicitis is appendiceal inflammation caused due

Appendicitis in children the disease the reasons

Appendicitis commonly known as appendicitis. Cecal appendix is near the head of

As the causes of acute appendicitis in children is not clear, in order to avoid baby suffering from appendicitis, his mother from the following aspects to note: Baby diet guide the formation of

How to prevent childhood appendicitis?

As the causes of acute appendicitis in children is not clear, in order to avoid

Insomnia is the inability of normal sleep, described the results obtained from the heart deprived of food or mental disorders. There is enough sleep, shallow sleep and relieve fatigue and flagrant

Insomnia is the inability of normal sleep

Insomnia is the inability of normal sleep, described the results obtained from

Colds are viruses diseases infected the upper respiratory tract and cold and influenza. They mainly used as nasal congestion and runny nose, sneezing, coughing, aversion manifests ordered cold,

Colds are viruses diseases infected the upper

Colds are viruses diseases infected the upper respiratory tract and cold and

Best of tcmwell.com

Main symptoms and signs chronic diarrhea without  recovery, or dawn diarrhea, thin and cold stool, or stool with undigested food, cold body and limbs, pale complexion, listlessness, poor appetite, or

Diarrhea Due To Yang Deficiency Of The Spleen And

Main symptoms and signs chronic diarrhea without recovery, or dawn diarrhea,

Unexplained leukemia is a malignant disease of the blood system. Characterized by leukocyte and naive cells (leukemia cells) in bone marrow hematopoietic tissue or other non-self to diffuse

Unexplained leukemia is a malignant disease

Unexplained leukemia is a malignant disease of the blood system. Characterized

(A) the principal is to increase the body resistance training can change the ability to adapt to the environment.(B) do a good job in life management, attention to food hygiene, and ensure good

The prevention of chronic gastritis

(A) the principal is to increase the body resistance training can change the

The slow progress of the disease is often recurrent, a good, middle-aged disease, and the incidence of age tend to increase. Some patients may have no symptoms, most patients have varying degrees of

chronic gastritis of Clinical manifestations

The slow progress of the disease is often recurrent, a good, middle-aged

Gastric cancer is a common digestive tract cancer, occurred in middle-aged and older men. The distribution is a clear regional differences, Latin America, Asia and Central Europe, such as Japan,

Gastric cancer is a common malignant tumor of

Gastric cancer is a common digestive tract cancer, occurred in middle-aged and

Understanding of the causes of high blood lipids Called diseases of modern civilization, one of the high blood lipids, where it scary? According to a nutritionist, said the blood can cause excessive

Understanding of the causes of hyperlipidemia

Understanding of the causes of high blood lipids Called diseases of modern