[The stimulation of glutamate uptake by the phorbol ester in rat cerebral cortex synaptosomes and cell line of human anaplastic astrocytoma BT-325].
The effects of protein kinase C (PKC) and protein kinase A (PKA) on the high affinity glutamate uptake in rat cerebral cortex synaptosomes, cell lines of human neuroblastoma SK-N-SH and human anaplastic astrocytoma BT-325 were studied by measurement of radioactivity of 3[H]-L-glutamate. The results were as follows: (1) PKC agonist phorbol-12-myristate, 13-acetate (PMA) stimulated the glutamate uptake in the rat cerebral cortex synaptosomes and cell line of BT-325, but not in the cell line of SK-N-SH. This effect of PMA was abolished in the presence of PKC antagonist sphingosine. (2) Glutamate uptake in all these three samples of neural tissues and cells was not affected by PKA agonist adenosine 3',5'-cyclicmonophosphate, N6,O2'-dibutyryl. The above results indicate that it is PKC that stimulates high affinity glutamate uptake in glial cells, although the possibility that neurons are also affected to some extent can not be ruled out.
Zhu
B G
BG
Department of Physiology, Second Military Medical University, Shanghai 200433.
Zhu
D H
DH
Chen
Y Z
YZ
D000818:Animals; D001254:Astrocytoma / Q000473:pathology*; D002540:Cerebral Cortex / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D008297:Male; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D013574:Synaptosomes / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D018698:Glutamic Acid; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate