Regulation of Na+ channel beta 1 and beta 2 subunit mRNA levels in cultured rat astrocytes.
Using quantitative competitive reverse transcription-polymerase chain reaction (RT-PCR), we found an increased level of Na+ channel beta 1 (Na beta 1) mRNAs in spinal cord astrocytes and in the B50 neuroblastoma cell line after exposure to 1 mM dibutyryl cAMP. In contrast, the calcium ionophore (1 microM A23187) did not affect Na beta 1 mRNA levels in these cells. Further, we amplified full length coding region of Na+ channel beta 2 (Na beta 2) mRNA from rat optic nerve and cultured astrocytes using RT-PCR. It appeared that the Na beta 2 mRNA level was increased by dibutyryl cAMP, but not by A23187, in spinal cord astrocytes. These findings suggest that the Na beta 1 and Na beta 2 mRNA levels in spinal cord astrocytes are influenced by increased cAMP but not by calcium.
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Y
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Department of Medicine, Sparks Center 865, University of Alabama at Birmingham 35294, USA. yoh@nrtc.dom.uab.edu
Lee
Y J
YJ
Waxman
S G
SG
D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D002478:Cells, Cultured; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D015222:Sodium Channels / Q000737:chemistry / Q000235:genetics*; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D010446:Peptide Fragments; D015222:Sodium Channels