kidney_upper_slim part of part of epithelial cell meso-epithelial cell epithelial cell of proximal tubule KUPO:0001044 An epithelial cell of the proximal tubule, commonly referred to as a proximal tubular epithelial cell, is a specialized brush border cell found lining the proximal tubule within the functional unit of the kidney, the nephron. These cells play a critical role in the resorption process in the kidney and are responsible for maintaining homeostasis, including blood filtration, electrolyte balance, and acid-base balance. Epithelial cells of the proximal tubule have a cuboidal shape and microvilli that increase surface area, facilitating effective reabsorption. The primary function of epithelial cells of the proximal tubule revolves around their ability to reabsorb approximately 60-70% of the glomerular filtrate, retaining essential substances such as sodium, glucose, amino acids, bicarbonate, and certain ions that are filtered out by the glomerulus. Additionally, these cells are also responsible for the secretion of organic acids, bases, and the hydrolysis of small proteins that are reabsorbed after filtration. Proximal tubule epithelial cells are highly susceptible to apoptosis, and damage to these cells by exposure to toxins, pathogens, or obstructive conditions may result in acute kidney injury. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) An epithelial cell of the proximal tubule of the kidney. https://cellxgene.cziscience.com/cellguide/CL_0002306 The vast majority of proximal tubule epithelial cells have a brush border, but there are rare exceptions. FMA:70973 kidney proximal tubule epithelial cell https://cdn.humanatlas.io/digital-objects/2d-ftu/kidney-renal-corpuscle/v1.2/assets/2d-ftu-kidney-renal-corpuscle.png nephron tubule epithelial cell kidney cortex tubule cell Homo sapiens proximal tubule