Acute changes in myo-inositol uptake and 22Na+ flux in murine neuroblastoma cells (N1E-115) following insulin.
myo-Inositol uptake was investigated in a murine neuroblastoma clone (N1E-115) to determine the effect of altered Na+,K+-ATPase activity. The Na+ ionophore monensin, and veratridine, an alkaloid affecting voltage-dependent Na+ entry, increased acute 22Na+ uptake and 22Na+ efflux from pre-loaded cells, concomitant with enhanced myo-inositol uptake. This effect was also seen following insulin. Insulin-stimulated myo-inositol uptake was inhibited by amiloride, ouabain and pyrithiamine. Amiloride inhibition suggests that activation of Na+/H+ exchange preceding Na+,K+-ATPase activation is involved in insulin stimulation of myo-inositol uptake. Pyrithiamine inhibition is an indication of prior activation of the Na+,K+-ATPase alpha + catalytic subunit by insulin. The results provide evidence that insulin contributes to the maintenance of Na+,K+-ATPase in neuronal tissue.
Dunlop
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M
Dimitriadis
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Larkins
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RG
D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D005947:Glucose / Q000378:metabolism; D007294:Inositol / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D013997:Time Factors
D007328:Insulin; D007294:Inositol; D012964:Sodium; D005947:Glucose