myo-Inositol transport in rat intestinal brush border membrane vesicles, and its inhibition by d-glucose
| Autor: | D. Natuzzi, Vito Scalera, G. Prezioso |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Monosaccharide Transport Proteins
Brush border Sodium Biophysics Biological Transport Active Myo-inositol transport chemistry.chemical_element In Vitro Techniques Biochemistry chemistry.chemical_compound Glucosides Animals Inositol Microvilli Chemistry Vesicle Rats Inbred Strains Cell Biology Membrane transport Rats Electrophysiology carbohydrates (lipids) Glucose Intestinal Absorption Active transport Cotransporter |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. 1062:187-192 |
| ISSN: | 0005-2736 |
| Popis: | The uptake of myo -inositol into rat intestinal brush border membrane vesicles (BBMV) has been investigated. It is demonstrated that myo -inositol is transported into the vesicles by a secondary active process, specifically using the sodium gradient as the driving force. In the absence of sodium gradient, the transport reaction is still sodium dependent, and rheogenic, indicating that a myo -inositol/sodium cotransport is likely to occur. A kinetic analysis shows an hyperbolic saturation process with a K m of 0.16±0.02mM with respect to myo -inositol and V max of 68.5±21.2pmol/min per mg protein. The transport is inhibited by d -glucose, phloridzin and few other sugars. The mechanism of d -glucose inhibition appears to be of the mixed type. Finally, the myo -inositol transport is trans-activated by myo -inositol itself, but not by d -glucose. It is concluded that myo -inositol is transported into rat intestine BBMV by a specific transport system, which is also able to bind d -glucose, but not efficiency transport it across the membrane. |
| Databáze: | OpenAIRE |
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