Renal oligopeptide reabsorption

Renal oligopeptide reabsorption is the part of renal physiology that deals with the retrieval of filtered oligopeptides, preventing them from disappearing from the body through the urine.

Almost all reabsorption takes place in the proximal tubule. Practically nothing is left in the final urine. Longer oligopeptides, such as angiotensin and glutathione are degraded by enzymes on the brush border, while shorter ones, such as carnosine, are transported across the apical membrane as a whole by the PepT 1 transporter, and degraded inside the proximal tubule cell.

Overview table

Characteristics of oligopeptide reabsorption
Characteristic	proximal tubule			loop of Henle	Distal convoluted tubule	Collecting duct system
Characteristic	S1	S2	S3	loop of Henle	Distal convoluted tubule	Collecting duct system
reabsorption (%)	99			Beyond the proximal tubule: 1%
reabsorption (mmoles/day)
Concentration
apical transport proteins	sodium-amino acid symporter PepT 1 (for short peptides, n=2 to 4)
basolateral transport proteins	amino acid transporter
Other reabsorption features

References

^ Walter F., PhD. Boron. Medical Physiology: A Cellular And Molecular Approaoch. Elsevier/Saunders. ISBN 1-4160-2328-3. Page 798

Physiology of the kidneys and acid–base physiology

Creating urine

Secretion	Clearance Pharmacokinetics Clearance of medications Urine flow rate
Reabsorption	Solvent drag Sodium Chloride Urea Glucose Oligopeptides Protein
Filtration	Renal blood flow Ultrafiltration Countercurrent exchange Filtration fraction

Other functions

Hormones	Antidiuretic hormone Aldosterone Atrial natriuretic peptide Renin Erythropoietin Calcitriol Prostaglandins
Fluid balance	Body water: Intracellular fluid/Cytosol Extracellular fluid (Interstitial fluid Plasma Transcellular fluid)
Acid–base balance	Darrow Yannet diagram Base excess Davenport diagram Anion gap (Delta ratio) Winters's formula Buffering Bicarbonate buffer system Respiratory compensation Renal compensation

Assessment and measurement

Other

Category:

Renal physiology