Both the filtrate and the dialyzate of agave pollen can activate the enzyme, thus proving that there was activating substance of the thiol group in agave pollen.
The remaining filtrate passes from the PCT into the loop of Henle, which starts in the cortex, then dips into the medulla before coming back into the cortex.
Now, all the stuff that get squeezed out of the blood into the glomerulus is called filtrate, which is then sent along to the elaborately twisting three-centimeter-long renal tubule.
These cells also are covered in microvilli that increase their surface area and help re-absorb much of the good stuff from the filtrate and back into the blood.
Sometimes fluid or electrolytes can move back from the filtrate into the blood - called reabsorption, and sometimes more fluid or electrolytes can move from the blood to the fitrate - called secretion.
The glomerular filtrate is not the same consistency as urine, as much of it is reabsorbed into the blood as the filtrate passes through the tubules of the nephron.
They use it to ramp up the concentration gradient earlier in the process, making the medulla even saltier for the filtrate that's back there going through the ascending limb.
The walls here are made of cuboidal epithelial cells, with big ol' mitochondria that make ATP, to power pumps that pull lots of sodium ions from the filtrate, using active transport.
Blood gets into the kidney through the renal artery, into tiny clumps of arterioles called glomeruli where it's initially filtered, with the filtrate, the stuff filtered out, moving into the renal tubule.
But in the parts of the nephron that reabsorb water, like the descending limb of the loop of Henle, water has to move easily through cells, from the filtrate to the blood.
This is possible because of special protein channels in their membranes called aquaporins that are on both the apical, or filtrate-facing side, and the basal, or capillary-facing side of the cells.