β-胡萝卜素拮抗促癌剂抑制细胞间隙连接通讯的机理探讨  

A STUDY ON THE MECHANISM OF PROTECTIVE EFFECTS OF β CAROTENE ON THE INHIBITION OF GAP JUNCTIONAL INTERCELLULAR COMMUNICATION BY TUMOR PROMOTER

作　　者：朱俊东[1] 糜漫天[1] 陈东升[1] 杨家驹[1] 石元刚[1] 

机构地区：[1]第三军医大学营养卫生学教研室

出　　处：《营养学报》1997年第2期141-145,共5页Acta Nutrimenta Sinica

基　　金：国家自然科学基金

摘　　要：运用荧光探针标记方法和放射免疫分析方法分别研究了细胞内游离Ｃａ２＋（［Ｃａ２＋］ｉ）和ｃＡＭＰ的变化与促癌剂ＴＰＡ抑制细胞间隙连接通讯（ＧａｐＪｕｎｃ－ｔｉｏｎａｌＩｎｔｅｒｃｅｌｕｌａｒＣｏｍｍｕｎｉｃａｔｉｏｎ，ＧＪＩＣ）功能的关系，以及β－胡萝卜素对这些变化的影响。结果表明：ＴＰＡ使［Ｃａ２＋］ｉ显著升高，ｃＡＭＰ水平显著降低，与对照组均有显著差异；β－胡萝卜素对［Ｃａ２＋］ｉ和ｃＡＭＰ的作用分别表现为降低和升高趋势，并对ＴＰＡ升高［Ｃａ２＋］ｉ、降低ｃＡＭＰ有一定的拮抗作用。提示：ＴＰＡ升高〔Ｃａ２＋〕ｉ、降低ｃＡＭＰ，影响间隙连接通道蛋白质磷酸化，这可能是其抑制细胞ＧＪＩＣ功能的重要原因之一，而β－胡萝卜素对［Ｃａ２＋］ｉ和ｃＡＭＰ的影响可能是其拮抗促癌剂抑制ＧＪＩＣ的部分作用机制。Ca 2+ and cAMP as intracellular messengers,play an important role in modulation of gap junctional intercellular communication(GJIC).The relationship between the inhibition of GJIC in Swiss NIH/3T3 cells by tumor promoter TPA(12 O tetradecanoyl 13 phorbol ace tate)and the changes of cytosolic free calcium([Ca 2+ ] i) and intracellular cAMP,and the effects of β carotene on these changes were studied.The results showed that [Ca 2+ ] i was siginificantly higher and cAMP levels were siginificantly lower in TPA treated group than that of control group.In β carotene group,[Ca 2+ ] i was decreased and cAMP levels were increased.In addition,β carotene could counteract the effects of TPA on [Ca 2+ ] i and cAMP.It suggested that the inhibition of GJIC between NIH/3T3 cells by TPA was correlated with the changes of [Ca 2+ ] i and cAMP,and the effects of β carotene on these changes might be one of the mechanisms by which β carotene protect the inhibition of GJIC by TPA.

关 键 词：Β胡萝卜素 促癌剂 GJIC 

分 类 号：R977.21[医药卫生—药品] R730.1[医药卫生—药学]