Renal potassium handling in rats with subtotal nephrectomy: modeling and analysis
Layton, Anita T.
MetadataShow full item record
Citation (published version)Anita T Layton, Aurelie Edwards, Volker Vallon. 2018. "Renal potassium handling in rats with subtotal nephrectomy: modeling and analysis." American Journal of Physiology: Renal Physiology, Volume 314, Issue 4, pp. F643 - F657. https://doi.org/10.1152/ajprenal.00460.2017
We sought to decipher the mechanisms underlying the kidney's response to changes in K+ load and intake, under physiological and pathophysiological conditions. To accomplish that goal, we applied a published computational model of epithelial transport along rat nephrons in a sham rat, an uninephrectomized (UNX) rat, and a 5/6-nephrectomized (5/6-NX) rat that also considers adaptations in glomerular filtration rate and tubular growth. Model simulations of an acute K+ load indicate that elevated expression levels and activities of Na+/K+-ATPase, epithelial sodium channels, large-conductance Ca2+-activated K+ channels, and renal outer medullary K+ channels, together with downregulation of sodium-chloride cotransporters (NCC), increase K+ secretion along the connecting tubule, resulting in a >6-fold increase in urinary K+ excretion in sham rats, which substantially exceeds the filtered K+ load. In the UNX and 5/6-NX models, the acute K+ load is predicted to increase K+ excretion, but at significantly reduced levels compared with sham. Acute K+ load is accompanied by natriuresis in sham rats. Model simulations suggest that the lesser natriuretic effect observed in the nephrectomized groups may be explained by impaired NCC downregulation in these kidneys. At a single-nephron level, a high K+ intake raises K+ secretion along the connecting tubule and reabsorption along the collecting duct in sham, and even more in UNX and 5/6-NX. However, the increased K+ secretion per tubule fails to sufficiently compensate for the reduction in nephron number, such that nephrectomized rats have an impaired ability to excrete an acute or chronic K+ load.
Showing items related by title, author, creator and subject.
Genome-wide association studies of serum magnesium, potassium, and sodium concentrations identify six loci influencing serum magnesium levels Meyer, Tamra E.; Verwoert, Germaine C.; Hwang, Shih-Jen; Glazer, Nicole L.; Smith, Albert V.; Van Rooij, Frank J. A.; Ehret, Georg B.; Boerwinkle, Eric; Felix, Janine F.; Leak, Tennille S.; Harris, Tamara B.; Yang, Qiong; Dehghan, Abbas; Aspelund, Thor; Katz, Ronit; Homuth, Georg; Kocher, Thomas; Rettig, Rainer; Ried, Janina S.; Gieger, Christian; Prucha, Hanna; Pfeufer, Arne; Meitinger, Thomas; Coresh, Josef; Hofman, Albert; Sarnak, Mark J.; Chen, Yii-Der Ida; Uitterlinden, André G.; Chakravarti, Aravinda; Psaty, Bruce M.; Van Duijn, Cornelia M.; Kao, W. H. Linda; Witteman, Jacqueline C. M.; Gudnason, Vilmundur; Siscovick, David S.; Fox, Caroline S.; Köttgen, Anna (Public Library of Science, 2010-8-5)Magnesium, potassium, and sodium, cations commonly measured in serum, are involved in many physiological processes including energy metabolism, nerve and muscle function, signal transduction, and fluid and blood pressure ...
Hacker, Elaine Samson (Boston University, 1950)Determinations of the normal values of sodium and potassium in human serum were made using a group of twenty-four healthy young men as subjects. It may be concluded from this research that the distribution of potassium is ...
ATP-sensitive potassium channel subcellular trafficking during ischemia, reperfusion, and preconditioning Ho, Joanne Cin-Yee (2014)Ischemic preconditioning is an endogenous cardioprotective mechanism in which short periods of ischemia and reperfusion provide protection when given before a subsequent ischemic event. Early mechanistic studies showed ...