Pelech S L, Pritchard P H, Vance D E
J Biol Chem. 1981 Aug 25;256(16):8283-6.
The effect of cAMP analogues on phosphatidylcholine formation via the CDP-choline pathway was investigated in cultured monolayers of rat hepatocytes. Treatment with chlorophenylthio-cAMP or the cAMP phosphodiesterase inhibitor, aminophylline, reduced the total uptake of [methyl-3H]choline by 32 and 26% (p less than 0.01), respectively. Chlorophenylthio-cAMP inhibited the incorporation of [methyl-3H]choline into phosphatidylcholine by 2.5-fold (p less than 0.001) and reduced the rate of phosphatidylcholine biosynthesis by approximately 40%. Aminophylline, 8-bromoadenosine 3':5'-monophosphate and N6,O2'-dibutyryladenosine 3':5'-monophosphate also inhibited [methyl-3H]choline incorporation into phosphatidylcholine. Although choline kinase and phosphocholinetransferase activities were stimulated by chlorophenylthio-cAMP treatment, CTP: phosphocholine cytidylyltransferase activity was reduced 46% (p less than 0.01). The results indicate that cytidylyltransferase may be phosphorylated and inhibited by cAMP-dependent protein kinases.
在大鼠肝细胞单层培养物中研究了环磷酸腺苷（cAMP）类似物对通过CDP-胆碱途径形成磷脂酰胆碱的影响。用氯苯硫基-cAMP或cAMP磷酸二酯酶抑制剂氨茶碱处理后，[甲基-3H]胆碱的总摄取量分别降低了32%和26%（p<0.01）。氯苯硫基-cAMP抑制[甲基-3H]胆碱掺入磷脂酰胆碱的能力达2.5倍（p<0.001），并使磷脂酰胆碱生物合成速率降低约40%。氨茶碱、8-溴腺苷3':5'-单磷酸和N6,O2'-二丁酰腺苷3':5'-单磷酸也抑制[甲基-3H]胆碱掺入磷脂酰胆碱。虽然氯苯硫基-cAMP处理可刺激胆碱激酶和磷酸胆碱转移酶活性，但CTP：磷酸胆碱胞苷转移酶活性降低了46%（p<0.01）。结果表明，胞苷转移酶可能被cAMP依赖性蛋白激酶磷酸化并受到抑制。
