Classic dRTA is treated with alkali replacement. If treatment is not instituted early on, however, chronic kidney disease may occur secondary to nephrocalcinosis or uncontrolled nephrolithiasis with consequent obstruction. Of…
In addition to acidosis, pRTA features hypokalemia because the nonreabsorbed bicarbonate produces a negative charge in the collecting duct lumen, promoting K+ secretion through ROM-K channels. If there is generalized…
VITAMIN D Vitamin D is a fat-soluble vitamin that can be acquired either from diet or from sunlight-induced conversion of epidermal fats. In either case, vitamin D undergoes numerous modifications…
Acidosis directly up-regulates ammoniagenesis through various mechanisms. Hypokalemia also up-regulates ammoniagenesis, whereas hyperkalemia down-regulates it, likely because of the effects of basolateral H+/K+ exchange on intracellular pH. Angiotensin II also…
MECHANISMS OF TUBULOGLOMERULAR FEEDBACK The available evidence suggests that the macula densa, located at the end of the thick ascending limb, senses tubular flow based on the concentrations of sodium…
AII also acts at the subfornical organ in the brain, located outside the blood-brain barrier, to promote the release of ADH (see Plate 3-17) and to stimulate thirst. Moreover, it…
EFFECTS ADH exerts multiple effects on the kidneys and cardiovascular system, which include the following: In collecting ducts, ADH binds to V2 receptors on the basolateral membrane of principal cells,…
SECRETION AND REABSORPTION (Continued) QUANTIFYING REABSORPTION AND SECRETION One means of assessing the secretion or reabsorption profile of a particular solute is to examine its changing concentration along the length…
Because of the countercurrent multiplier system, there is a strong gradient for water reabsorption from the collecting duct that increases in strength toward the papillae. Because water reabsorption is a…
Descending Thin Limb. The descending thin limb reabsorbs an additional fraction of the filtered water. There is a large gradient for water reabsorption from this segment even though it reabsorbs…
