3'-甲基-4-二甲氨基偶氯苯对大鼠肝脏磷脂代谢的影响

EFFECT OF 3'-ME-DAB ON THE METABOLISM OF PHOSPHOLIPID IN RAT LIVER

探讨3'—甲基—4—二甲氨基偶氮苯（3'－Me－DAB）诱发大鼠肝癌过程中肝脏磷脂代谢的变化。用3'－Me－DAB诱发Wistar大鼠肝癌，同时辅以低胆碱饮食，TLC分离磷脂组分，Rouser法测定第6、9、12、16、20周肝脏中总磷脂及各磷脂组分含量。结果：发现诱癌组总磷脂和磷脂酸胆碱（PC）的含量不断下降，且两者变化一致；鞘磷脂（SM）在3'—Me—DAB加普通饮食组（A组）诱癌早期即迅速增高，超过对照组约1倍，并一直维持至肝癌形成，而在3'—Me—DAB加低胆碱饮食组（B组）虽然早期也升高，但当第20周肿瘤发生转移时降至对照组以下；溶血磷脂酰胆碱（LPC）仅在B组晚期出现下降。不含胆碱基因的磷脂组分：磷脂酰乙醇胺（PE）、磷脂酰丝氨酸（PS）和磷脂酰肌醇（PI）在3'—Me—DAB诱癌晚期均降低，B组尤为明显。缩醛磷脂的含量在整个诱癌过程中未见明显变化。结论：3'－Me－DAB诱发大鼠肝癌过程中主要影响PC和SM的代谢，表现为PC降低，SM增高。低胆碱饮食能缯强3'—Me—DAB对大鼠肝脏磷脂代谢的影响。

PURPOSE To study the changes of phosphoipid metabolism in rat liver during hepatocarcinogenesis by 3' -Me-DAB.METHODS 3' -Me-DAB was chosed to induce hepatocarcinoma in Wistar male rats and less choline diet was administrated simultaneously, phospholpids of liver was separated and quantitated at 6, 9, 12, 16, 20week respectively.RESULTS Compared with the control, both total phospholipid and phosphatidylcholine (PC) level decreased gradually. Sphingomyline (SM) level elevated rapidly in early time in rats treated with 3'-Me-DABand common diet (group A) and sustained till the formation of hepato-Cellular carcinoma. Though SM inereased in early time in rats treated with 3'-Me-DAB and less choline diet (group B), it reduced to lower level than control at 20th week when tumor had metastasis. LPC decreased just in the rats of group B. Phospholipids without choline residue, such as phosphatidylethnilamine (PE), phosphatidylinositol (PI) and phsphatidylserine (PS), their levels decreased in the later period of hepatocarinogenesis, especially in the rats of group B. The content of plasmalogen in rat liver had no change during whole period of carcinogenesis.CONCLUSIONS The main Change of Phospholipids are PC and SM and expressed as PC elevated, SM decreased during hepatocarcinogenesis by 3'-Me-DAB. Less choline diet can enhance the effect of 3'-Me-DAB on the metabolism of phospholipid in rat liver.