The kidney is just like a sieve in our body. In simple terms, blood flows through the glomeruli and big molecules cannot pass the holes in it. After being filtered, initial urine is formed. The appearance of proteinuria is close related to the problem with glomeruli. Fluid and other solute in blood must go through the capillaries when they are filtered.. The three layers, say, epithelial cells, basilar membrane and endothelial cells in capillaries, are called the filtration membrane of glomeruli. There are some holes in the membranes and only some small molecules can get through. This is the mechanical barrier. What's more, in the surface of the three layers, there are negative charges, so the solute with negative charge as well can not get through the membrane. This is called charge barrier. Under normal condition, most of the protein in blood can not pass the barriers in glomeruli, especially those which have negative charges. Only a small amount of protein can get through, but they will be reabsorbed by renal tubules. So, there is little protein in urine with a normal kidney function.Can Urinary Tract Infection Cause Nephrotic Syndrome
Generally speaking, there are 10-15kg plasma protein go through the kidney circulation, and there are only about 150mg can be excreted outside the body along with the urine. When kidney function fails working or there are problems with glomeruli due to some pathological changes of filtration membranes, for instance, the widening holes in the membrane, and less negative charges with these membrane. Also, the pathological changes are much severer than the reabsorption function of tubules, so there are more and more protein leaked out, and mass proteinuria appears.CKD Stage 3 Treatment and CKD Stage 4 Treatment
Having known the function of kidney glomeruli and tubules, you must understand how the urinary protein emerges. Proteinuria indicates problems with kidney function and especially the pathological changes of glomeruli, so it is usually attached much importance to when you have CKD. Protein in urine is indeed a sign of CKD and it needs to be noticed. If you want to know more, you are welcome to talk with the consultant online or leave a message to me.
