Higher K + consumption leads to accumulation off K + about interstitium of your own kidney through medullary recycling. Earlier education advised this particular increase in interstitial K + attention carry out produce an inhibitory influence on salt transport in the the new heavy ascending limb and you may proximal tubule, which often perform end in increased Na + and you will drinking water birth on distal nephron, making it possible for enhanced K + hormonal (six, 53, 54). Because discussed less than, previous research has concerned about exactly how K + consumption modulates transportation regarding reasonable-strength very early distal convoluted tubule (DCT) as a way to to change tubular flow in order to K + secretory web sites. This research recommend that the end result from slimming down K + so you can regulate move and you may beginning of Na + so you can K + secretory websites is much more regionalized and you will confined into the down potential distal nephron.
Current findings suggest that this process is far more regionalized and you may implicate the newest distal convoluted tubule (DCT) since the a renal K + alarm
The new DCT constitutes a proximal part (DCT1) and you will an effective distal piece (DCT2). From the DCT1, salt transport try inspired exclusively by thiazide-delicate NaCl cotransporter (NCC), whereas within the DCT2, electroneutral NaCl transportation coexists which have electrogenic Na + and you may K + transport routes (28). On the DCT2, aldosterone sensitivity, that’s important to assists K + homeostasis, begins and you may extends to this new event duct. Cells of your own very early DCT exert a substantial, albeit secondary, role from inside the K + hormonal ideal because of the proven fact that changes in transportation throughout the very early DCT control new beginning out of NaCl to the downstream connecting tubule and you can colleting duct, where the epithelial salt route (ENaC) mediates electrogenic Na + reabsorption and you can where K + is actually produced (Fig. 3).
ENaC, epithelial sodium route; Cd, collecting duct
Fig. step 3.Old education (6, 53, 54) has suggested you to maintenance from K + homeostasis on the form of highest K + slimming down intake try brought about by an inhibitory effect of K + with the Na + reabsorption throughout the thick rising limb and you will proximal tubule of your own kidney, and so assisting increased beginning out of Na + so you’re able to servings of your own distal nephron responsive to mineralocorticoid activity. Highest K + intake prevents electroneutral NaCl transportation on the proximal part of the distal convoluted tubule (DCT1). Brand new resulting boost in Na + delivery and you may move in addition to enhanced aldosterone encourages electrogenic K + secretion due to ROMK. Aldosterone and you will disperse can also increase K + secretion through the Maxi-K route. Increased secretion might be started on K + entry toward digestive system thanks to an enteric K + -feeling apparatus one suppress Na + -Cl ? cotransporter (NCC) pastime regarding absence of change in plasma attention.
The spot of your own DCT1 quickly upstream in the aldosterone-delicate distal nephron (ASDN) and its own reasonable capacity characteristics make this segment a more almost certainly site to own alterations in fat loss K + consumption so you’re able to modulate Na + transport and make certain that downstream beginning of Na + is strictly extent wanted to be sure repairs out-of K + homeostasis without creating undesireable effects for the volume. Slimming down consumption of K + , which causes alterations in plasma K + amount, results in a keen inhibitory affect NCC hobby. This means that, Na + delivery and you may circulate is actually increased to new aldosterone delicate K + secretory segments found in the later portions of one’s DCT (DCT2) and you may collecting duct. At the same time, the rise in the plasma K + quantity after the consumption produces aldosterone discharge regarding the adrenal gland, which often facilitates electrogenic K + secretion compliment of ROMK. Both enhanced circulate and you may aldosterone turn on K + secretion from Maxi-K sugar daddy Liverpool channel (15, 28).