Tubuloglomerular feedback

Tubuloglomeruläres feedback (TGF ) is a mechanism that allows the filtration of a single nephron is regulated in the kidney.

If the glomerular filtration rate (GFR ) is too high, exceeds the amount of sodium chloride (NaCl ) in the primary urine resorption of the renal tubule. This leads to the increase of NaCl concentration in the tubule, which is from the sensor function of macula densa, a part of the juxtaglomerular apparatus, via an ion transporters (Na / K / 2Cl - symporter ) registered. Thus, with increasing NaCl content in the distal tubule ( middle piece ) there is a reduction in glomerular filtration rate of the same nephron.

The reduction of the glomerular filtration rate is mediated by adenosine, leading to smooth muscle contraction in the afferent. Prostaglandins mediate, however, an increased blood flow to the kidneys, which leads to increased NaCl and water excretion, thus for stronger GFR. Nonsteroidal anti-inflammatory drugs ( NSAIDs) reduce, due to its inhibition of prostaglandin synthesis, the GFR.