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Los transportadores de hexosa facilitadores de los mamíferos median el transporte del ácido deshidroascorbico

J C Vera¹, C I Rivas, J Fischbarg

¹Program in Molecular Pharmacology and Therapeutics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.

|July 1, 1993

Resumen

Los transportadores de hexose de los mamíferos transportan eficientemente el ácido deshidroascorbico, la forma oxidada de la vitamina C. Este descubrimiento revela una vía clave para la absorción y acumulación celular de vitamina C contra gradientes de concentración.

Área de la Ciencia:

Biología celular Biología celular.
La bioquímica es la bioquímica.
Ciencias de la Nutrición Ciencias de la Nutrición

Sus antecedentes:

La vitamina C (ácido ascórbico) es esencial para la salud humana, pero sus mecanismos de absorción celular siguen sin estar claros.
Se cree que la captación celular de ácido ascórbico involucra transportadores específicos de la membrana.
Investigaciones anteriores sugirieron un vínculo entre el transporte de ácido ascórbico y los transportadores de hexosa en células de mamíferos.

Objetivo del estudio:

Investigar el papel de los transportadores de hexosa facilitadores de mamíferos en la absorción de vitamina C.
Para determinar si los transportadores de hexosa pueden transportar el ácido deshidroascorbico (DHA).
Para aclarar el mecanismo de la acumulación celular de vitamina C.

Principales métodos:

Utilizó el sistema de expresión de ovocitos de Xenopus laevis para estudiar la función del transportador.
Transportadores de hexosa facilitadores de mamíferos expresados en los ovocitos.
Se midió la absorción de ácido deshidroascorbico y la acumulación de vitamina C en ovocitos y neutrófilos humanos.

Principales resultados:

Los transportadores de hexosas facilitadoras de los mamíferos transportaron eficientemente el ácido deshidroascorbico (DHA).
Se identificaron dos vías distintas de transporte de DHA (de alta y baja afinidad) en la expresión de los ovocitos.
Los ovocitos que expresan transportadores de hexosa acumulan vitamina C contra un gradiente de concentración cuando se les suministra DHA.
Se observaron resultados similares en los neutrófilos humanos, lo que confirma la relevancia fisiológica.

Conclusiones:

Los transportadores de hexosa facilitadores de los mamíferos representan una vía significativa para la absorción celular de vitamina C.
Estos transportadores facilitan la acumulación de vitamina C contra un gradiente de concentración a través del DHA.
Este hallazgo proporciona un nuevo mecanismo para la homeostasis celular de la vitamina C.

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