Argipressin(4—8) Upregulate CTP: Phosphocholine Cytidylyltransferase in Rat Hippocampal Neurons

XU Kan-Yan, XIONG Ying, DU Yu-Cang^*
( Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, the Chinese Academy of Sciences, Shanghai 200031, China )

Abstract    In order to study the effect of argipressin(4—8)(AVP_4—8) on the mRNA level and activity of cytidine triphosphate: phosphocholine cytidylyltransferase(CCT) in rat hippocampal neurons, and elucidate it's possible mechanism. Rat hippocampal neurons treated with AVP_4—8 or actinomycin D were incubated with different time periods. The mRNA level of CCT was detected using RT-PCR plus Southern blot, CCT activity was determined by measuring the rate of incorporation of ［¹⁴C］- phosphocholine into cytidine diphosphate-choline(CDP-choline). It was found that AVP_4—8 could upregulate the CCT mRNA in rat hippocampal neurons. ZDC(C)PR, the antagonist of AVP_4—8, could greatly inhibit this upregulation. Using actinomycin D to inhibite the eucaryotic transcription, it was found that the halflife of CCT mRNA could be prolonged by coincubation with AVP_4—8. Meanwhile, AVP_4—8 could also increase CCT activity in rat hippocampal neurons. These results demonstrated that AVP_4—8 upregulated CCT mRNA level and its activity through stabilizing the CCT mRNA in rat hippocampal neurons.
Key words    argipressin; CTP: phosphocholine cytidylyltransferase; hippocampus; phosphatidylcholine; actinomycin D

^*Corresponding author: Tel, 86-21-64374430; Fax, 86-21-64338357； e-mail, duyc@ sunm.shnc.ac.cn