• Firstly, an Na+/K+ ATPase on the basolateral membrane of the proximal tubule cell uses ATP molecules to move 3 sodium ions outward into the blood, while bringing in 2 potassium ions. (wikipedia.org)
  • The SGLT proteins use the energy from this downhill sodium ion gradient created by the ATPase pump to transport glucose across the apical membrane, against an uphill glucose gradient. (wikipedia.org)
  • SGLTs transport sodium and glucose into cells using the sodium gradient created by sodium/potassium ATPase pumps at the basolateral cell membranes. (bjcardio.co.uk)
  • Glucose enters at the luminal side of the proximal tubular cells by an active carrier-mediated transport process that requires energy provided by the sodium gradient between the intra- and extracellular compartments generated by sodium-potassium ATPase. (medscape.com)
  • Sodium-dependent glucose cotransporters (or sodium-glucose linked transporter, SGLT) are a family of glucose transporter found in the intestinal mucosa (enterocytes) of the small intestine (SGLT1) and the proximal tubule of the nephron (SGLT2 in PCT and SGLT1 in PST). (wikipedia.org)
  • SGLT2 is only found in kidney tubules and in conjunction with SGLT1 resorbs glucose into the blood from the forming urine. (wikipedia.org)
  • By inhibiting SGLT2, and not targeting SGLT1, glucose is excreted which in turn lowers blood glucose levels. (wikipedia.org)
  • Because sodium and glucose are moved in the same direction across the membrane, SGLT1 and SGLT2 are known as symporters. (wikipedia.org)
  • Approximately 10% of renal glucose re-absorption occurs via SGLT1, and the remaining 90% occurs via SGLT2, which is found in the early proximal tubule. (bjcardio.co.uk)
  • SGLT2, a high-capacity, low-affinity transporter of glucose and sodium is found in high concentration at the brush border membrane of the S1 and S2 segment of the proximal convoluted tubule (PCT). (bjcardio.co.uk)
  • SGLT2 binds to sodium and glucose in the filtrate and these compounds are translocated across the apical cell membrane, an active process driven by the electrochemical sodium gradient between tubular filtrate and the cell. (bjcardio.co.uk)
  • Members of the GLUT family of glucose uniporters then transport the glucose across the basolateral membrane, and into the peritubular capillaries. (wikipedia.org)
  • The second stage of re-absorption is the transport of glucose through the utilisation of GLUT2 transporters in the basolateral membrane. (bjcardio.co.uk)
  • Renal glucosuria is the excretion of glucose in the urine in detectable amounts at normal blood glucose concentrations in the absence of any signs of generalized proximal renal tubular dysfunction. (medscape.com)
  • Reabsorption of glucose predominantly occurs on the brush border membrane of the convoluted segment of the proximal tubule. (medscape.com)
  • This action creates a downhill sodium ion gradient from the outside to the inside of the proximal tubule cell (that is, in comparison to both the blood and the tubule itself). (wikipedia.org)
  • They inhibit glucose re-absorption in the proximal renal tubules providing an insulin independent mechanism to lower blood glucose. (bjcardio.co.uk)
  • The glucose transporters expressed in the renal proximal tubule ensure that less than 0.5 g/day (range 0.03-0.3 g/d) is excreted in the urine of healthy adults. (medscape.com)
  • These are expressed in the renal proximal tubule only and not the renal medulla. (medscape.com)
  • As the rate of glucose entering the nephron rises above 260-350mg/1.73m 2 /min (14.5-19.5mmol/1.73m 2 /min), the excess glucose exceeds the reabsorptive capacity of proximal tubule and is excreted in the urine (i.e. glucosuria). (medscape.com)
  • This form of glucose transport is predominantly mediated by members of the GLUT transporter family. (medscape.com)
  • ii) The glucose carriers expressed in the basolateral domain are GULT-1 and GLUT-2 that do not require energy, sodium, or any other ion. (medscape.com)
  • In August 1960, in Prague, Robert K. Crane presented for the first time his discovery of the sodium-glucose cotransport as the mechanism for intestinal glucose absorption. (wikipedia.org)
  • The inherited from of this disorder is called familial renal glucosuria (FRG). (medscape.com)
  • Renal glucosuria has also been reported in patients with acute pyelonephritis in the presence of anormal blood glucose level. (medscape.com)
  • In health individuals this equates to a blood glucose concentration of approximately 200mg/dL (11mmol/L), which is believed to be threshold for the appearance of glucosuria. (medscape.com)
  • Glucose is then transported passively by GLUT2 along its concentration gradient into the interstitium. (bjcardio.co.uk)
  • Two means of glucose transport are noted: facilitative and secondary active transport. (medscape.com)
  • Glucose enters the cell along with sodium, and sodium exits the cell at the basolateral side of the cell, which is sodium-independent and a facilitative transport requiring no energy. (medscape.com)
  • Treatment with traditional glucose-lowering therapies, including metformin, sulphonylureas and insulin, is commonly limited by gastrointestinal side effects, weight gain and hypoglycaemia. (bjcardio.co.uk)
  • Its use as a therapeutic target is limited by side effects from malabsorption of glucose and galactose in the small intestine. (bjcardio.co.uk)