Acute changes in myo‐inositol uptake and 22Na+ flux in murine neuroblastoma cells (N1E‐115) following insulin

[摘要]

myo-Inositol uptake was investigated in a murine neuroblastoma clone (N1E-115) to determine the effect of altered Na⁺,K⁺-ATPase activity. The Na⁺ ionophone 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 α⁺ catalytic subunit by insulin. The results provide evidence that insulin contributes to the maintenance of Na⁺, K⁺-ATPase in neuronal tissue.

[学科分类] 生物化学/生物物理

[关键词] myo-Inositol uptake;Na+;(Na+ + K+)-ATPase;Insulin;Pyrithiamine;(Neuroblastoma clone)