Official websites use. Share sensitive information only on official, secure websites. Hotait, J. Lo Cascio, and E. Choos contributed equally to this work. Correspondence: B. Shepard blythe. Keywords: gluconeogenesis, glycolysis, oxidative phosphorylation, proximal tubule, sodium-glucose cotransporters. Through the processes of filtration, reabsorption, and secretion, the kidneys ensure that solutes and other small molecules are either returned to circulation, catabolized within renal epithelial cells, or excreted through the process of urination.
Although this occurs throughout the renal nephron, one segment is tasked with the bulk of solute reabsorptionβthe proximal tubule. Among others, the renal proximal tubule is entirely responsible for the reabsorption of glucose, a critical source of energy that fuels the body. In addition, it is the only other site of gluconeogenesis outside of the liver.
When these processes go awry, pathophysiological conditions such as diabetes and acidosis result. In this review, we highlight the recent advances made in understanding these processes that occur within the renal proximal tubule. We focus on the physiological mechanisms at play regarding glucose reabsorption and glucose metabolism, emphasize the conditions that occur under diseased states, and explore the emerging class of therapeutics that are responsible for restoring homeostasis.
Renal tissue is among some of the most intricate and essential in the human body as its functions of filtration, glucose handling, and water balance serve to maintain homeostasis on several fronts. The journey of fluid through the nephron units begins with the glomerulus, followed by the proximal convoluted tubule PT where reabsorption of solutes occurs early on to prevent buildup and nephrotoxicity 2 , 3.
The fluid continues through the loop of Henle, the distal convoluted tubule, and finally the collecting duct, where, through the coordinated processes of reabsorption and secretion, urine is concentrated, acid-base balance is maintained, and sodium and phosphate levels are fine-tuned.
