Second, macula densa cells release prostaglandins, which triggers granular juxtaglomerular cells lining the afferent arterioles to release renin into the bloodstream . ( The juxtaglomerular cells can also release renin independently of the macula densa.
22.
In the kidneys, the glomerular filtration rate ( GFR ) is regulated by several mechanisms including tubuloglomerular feedback ( TGF ), in which an increased distal tubular sodium chloride concentration causes a basolateral release of ATP from the macula densa cells.
23.
Macula densa cells sense changes in sodium chloride level, and will trigger an autoregulatory response to increase or decrease reabsorption of ions and water to the blood ( as needed ) in order to alter blood volume and return blood pressure to normal.
24.
The macula densa senses this drop in salt concentration and responds through two mechanisms : First, it triggers dilation of the renal afferent arteriole, decreasing afferent arteriole resistance and, thus, offsetting the decrease in glomerular hydrostatic pressure caused by the drop in blood pressure.
25.
As part of the body s blood pressure regulation, the macula densa monitors filtrate osmolarity; if it falls too far, the macula densa causes the afferent arterioles of the kidney to dilate, thus increasing the pressure at the glomerulus and increasing the glomerular filtration rate.
26.
As part of the body s blood pressure regulation, the macula densa monitors filtrate osmolarity; if it falls too far, the macula densa causes the afferent arterioles of the kidney to dilate, thus increasing the pressure at the glomerulus and increasing the glomerular filtration rate.
27.
When the macula densa detects an elevated GFR, it releases several molecules that cause the glomerulus to rapidly decrease its filtration rate . ( Technically, the macula densa detects a SNGFR, single nephron GFR, but " GFR " is used here for simplicity .)
28.
When the macula densa detects an elevated GFR, it releases several molecules that cause the glomerulus to rapidly decrease its filtration rate . ( Technically, the macula densa detects a SNGFR, single nephron GFR, but " GFR " is used here for simplicity .)
29.
Renin cleaves the peptide bond between the leucine ( Leu ) and valine ( Val ) residues on angiotensinogen, creating the ten-amino acid peptide ( des-Asp ) angiotensin I . Renin is produced in the kidneys in response to renal sympathetic activity, decreased intrarenal blood pressure ( < 90mmHg systolic blood pressure ) at the juxtaglomerular cells, or decreased delivery of Na + and Cl-to the macula densa.
