Renal oligopeptide reabsorption is the part of renal physiology

Renal physiology

Renal physiology is the study of the physiology of the kidney. This encompasses all functions of the kidney, including reabsorption of glucose, amino acids, and other small molecules; regulation of sodium, potassium, and other electrolytes; regulation of fluid balance and blood pressure;...

 that deals with the retrieval of filtered oligopeptide

Oligopeptide

An oligopeptide consists of between 2 and 20 amino acids and includes dipeptides, tripeptides, tetrapeptides, pentapeptides, etc.Examples of oligopeptides include:...

s, preventing them from disappearing from the body through the urine.

Almost all reabsorption takes place in the proximal tubule

Proximal tubule

The proximal tubule is the portion of the duct system of the nephron of the kidney which leads from Bowman's capsule to the loop of Henle.-Structure and appearance:...

. Practically nothing is left in the final urine. Longer oligopeptides, such as angiotensin

Angiotensin

Angiotensin, a peptide hormone, causes blood vessels to constrict, and drives blood pressure up. It is part of the renin-angiotensin system, which is a major target for drugs that lower blood pressure. Angiotensin also stimulates the release of aldosterone, another hormone, from the adrenal cortex...

  and glutathione

Glutathione

Glutathione is a tripeptide that contains an unusual peptide linkage between the amine group of cysteine and the carboxyl group of the glutamate side-chain...

 are degraded by enzymes on the brush border

Brush border

A brush border is the name for the microvilli-covered surface of simple cuboidal epithelium and simple columnar epithelium cells found in certain locations of the body. Microvilli are approximately 100 nanometers in diameter and their length varies from approximately 100 to 2,000 nanometers in...

, while shorter ones, such as carnosine

Carnosine

Carnosine is a dipeptide of the amino acids beta-alanine and histidine. It is highly concentrated in muscle and brain tissues....

, are transported across the apical membrane as a whole by the PepT 1

PepT 1

Peptide transporter 1 also known as solute carrier family 15 member 1 is a protein that in humans is encoded by SLC15A1 gene. PepT 1 is a solute carrier for oligopeptides...

 transporter, and degraded inside the proximal tubule cell.

Overview table

Characteristics of oligopeptide reabsorption

Characteristic	proximal tubule Proximal tubule The proximal tubule is the portion of the duct system of the nephron of the kidney which leads from Bowman's capsule to the loop of Henle.-Structure and appearance:...			loop of Henle Loop of Henle In the kidney, the loop of Henle is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. Named after its discoverer F. G. J...	Distal convoluted tubule Distal convoluted tubule The distal convoluted tubule is a portion of kidney nephron between the loop of Henle and the collecting duct system.- Physiology :It is partly responsible for the regulation of potassium, sodium, calcium, and pH...	Collecting duct system Collecting duct system The collecting duct system of the kidney consists of a series of tubules and ducts that connect the nephrons to the ureter. It participates in electrolyte and fluid balance through reabsorption and excretion, processes regulated by the hormones aldosterone and antidiuretic hormone.There are several...
	S1	S2	S3
reabsorption (%)	99			Beyond the proximal tubule: 1%
reabsorption (mmoles Mole (unit) The mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as an amount of a substance that contains as many elementary entities as there are atoms in 12 grams of pure carbon-12 , the isotope of carbon with atomic weight 12. This corresponds to a value... /day)
Concentration
apical transport proteins	sodium-amino acid symporter PepT 1 PepT 1 Peptide transporter 1 also known as solute carrier family 15 member 1 is a protein that in humans is encoded by SLC15A1 gene. PepT 1 is a solute carrier for oligopeptides...  (for short peptides, n=2 to 4)
basolateral  transport proteins	amino acid transporter Amino acid transporter An amino acid transporter is a membrane transport protein that transports amino acids. They are mainly of the solute carrier family.-Solute carrier family examples:* high affinity glutamate and neutral amino acid transporter...
Other reabsorption features