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Biotin Transport in Primary Culture of Astrocytes: Effect of Biotin Deficiency
Author(s) -
RodriguezPombo Pilar,
Ugarte Magdalena
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb11364.x
Subject(s) - biotin , biocytin , thioctic acid , biochemistry , biotin deficiency , chemistry , thiamine , biology , endocrinology , lipoic acid , central nervous system , antioxidant
The uptake of radioactive biotin has been studied in glial cell cultures from dissociated cerebral hemispheres of newborn rats. We describe saturable kinetics for the biotin uptake at biotin concentrations of < 60 n M and linear at >60 n M . The uptake appeared temperature sensitive, Na + independent, nonsensitive to valinomycin, and not affected by metabolic inhibitors such as sodium fluoride or azide. Lipoic acid and biocytin were effective in inhibiting the biotin uptake. These findings are consistent with biotin uptake by the primary culture of astrocytes as a process of facilitated diffusion. Moreover, biotin uptake in astrocytes grown in biotin‐restricted conditions was significantly higher compared with the control. This increase appeared mediated through a pronounced increase (10‐fold) in the V max of the biotin uptake without any change in the apparent K m .