Damron D S, Dorman R V
Dept. of Biological Sciences, Kent State University, OH 44242.
Neurochem Res. 1988 Aug;13(8):777-83. doi: 10.1007/BF00971602.
Rat brain minces were used to investigate the effects of nucleotides on the metabolism of arachidonic acid in nerve tissue. Brain free fatty acids, neutral lipids and phospholipids, were radiolabeled in vivo following intracerebral injection of [3H]arachidonic acid. Minces were prepared from the radiolabeled cerebra and were incubated in a modified Krebs-Ringer buffer with and without various nucleotides. The incubation-induced accumulation of unesterified [3H]arachidonate was reduced in the presence of CDPcholine, ATP, CTP, GTP, and UTP. These nucleotides inhibited choline and inositol glycerophospholipid hydrolysis. They also reduced the amount of labeled diglycerides. However, CDPethanolamine had no effect on arachidonic acid metabolism in the mince preparation and CMP appeared to stimulate further hydrolysis of choline glycerophopholipids, resulting in increased accumulation of [3H]arachidonic acid and labeled diglycerides. We suggest that the production of unesterified [3H]arachidonate and labeled diglycerides is due to the involvement of more than one catabolic reaction, since the high energy nucleotides had similar effects on fatty acid accumulation, but different effects on phospholipid labeling.
用大鼠脑匀浆来研究核苷酸对神经组织中花生四烯酸代谢的影响。在脑内注射[3H]花生四烯酸后，脑游离脂肪酸、中性脂质和磷脂在体内被放射性标记。从放射性标记的大脑中制备匀浆，并在改良的krebs - Ringer缓冲液中分别添加和不添加各种核苷酸进行孵育。在存在CDP胆碱、ATP、CTP、GTP和UTP的情况下，孵育诱导的未酯化[3H]花生四烯酸盐的积累减少。这些核苷酸抑制胆碱和肌醇甘油磷脂的水解。它们还减少了标记的甘油二酯的量。然而，CDP乙醇胺对匀浆制剂中的花生四烯酸代谢没有影响，而CMP似乎刺激胆碱甘油磷脂的进一步水解，导致[3H]花生四烯酸和标记的甘油二酯的积累增加。我们认为，未酯化[3H]花生四烯酸盐和标记的甘油二酯的产生是由于不止一种分解代谢反应的参与，因为高能核苷酸对脂肪酸积累有相似的影响，但对磷脂标记有不同的影响。
