Related Experiment Video
Updated: May 13, 2026
10:35
Extracellular Glucose Depletion as an Indirect Measure of Glucose Uptake in Cells and Tissues Ex Vivo
Published on: April 6, 2022
Robert K. Crane-Na(+)-glucose cotransporter to cure?
1Department of Physiology, Otago School of Medical Sciences, University of Otago Dunedin, New Zealand.
Frontiers in Physiology
|March 26, 2013
Summary
Dr. Robert K. Crane
Area of Science:
- Physiology
- Biochemistry
- Gastroenterology
Background:
- Dr. Robert K. Crane's career significantly advanced the understanding of intestinal carbohydrate metabolism and transport.
- His early hypothesis on nutrient absorption laid the groundwork for critical medical treatments.
Purpose of the Study:
- To highlight Dr. Robert K. Crane's seminal contributions to the understanding of intestinal glucose absorption.
- To emphasize the impact of his "cotransport" hypothesis on modern medicine, particularly oral rehydration therapy.
Main Methods:
- This perspective reviews Dr. Crane's early life and academic career.
- It focuses on his hypothesis of coupled sodium-glucose absorption in the small intestine.
Main Results:
- Crane's hypothesis explained the mechanism of sodium-glucose cotransport.
- This provided the physiological basis for oral rehydration therapy (ORT).
Conclusions:
- Dr. Crane's Na(+)-glucose cotransporter hypothesis, proposed over 50 years ago, has had a profound impact on human health.
- His work is directly linked to the life-saving success of oral rehydration therapy, which benefits millions globally.
Related Concept Videos
01:55Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
01:32Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
01:27Glucose Transporters
Glucose transporters facilitate the transport of glucose across the cell membrane. In addition to glucose, some glucose transporters can also aid the movement of other hexoses such as fructose, mannose, and galactose.
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
01:26Glucose Absorption Into the Small Intestine
Complex carbohydrates consumed cannot be absorbed into the small intestine in their original form. First, they must be hydrolyzed to a monosaccharide form such as glucose or galactose. These monosaccharides are then transported across the intestinal membrane and into the blood via transcellular transport. The intestinal epithelial cells allow the movement of these monosaccharides with a defined 'entry' through membrane transporter proteins present on their apical membrane and 'exit' via the...
01:23Transcellular Transport of Solutes
Transcellular transport of solutes is the movement of substances like monosaccharides and amino acids through polarized cells. This transport mechanism is primarily seen in epithelial and endothelial cells aided by membrane transport proteins such as channels and transporters. The tight junctions between these cells confine the membrane proteins to the two sides of the cell. The epithelial cells have distinct apical and basolateral domains. In contrast, the endothelial cells show the luminal...
01:30Membrane Proteins
Plasma membranes have integral transmembrane proteins involved in facilitated transport. These proteins are collectively referred to as transport proteins, and they function as either channels for the material or as carriers themselves. Channel proteins have hydrophilic domains exposed to the intracellular and extracellular fluids and a hydrophilic channel through their core that provides a hydrated opening for solutes to pass through the membrane layers. Passage through the channel allows...