Inhibition of gap junctional intercellular communication by barbiturates in long-term primary cultured rat hepatocytes is correlated with liver tumour promoting activity.
Inhibition of gap junctional intercellular communication by barbiturates in long-term primary cultured rat hepatocytes is correlated with liver tumour promoting activity.
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在长期原代培养的大鼠肝细胞中，巴比妥类药物对间隙连接细胞间通讯的抑制与肝脏肿瘤促进活性相关。
DOI：
10.1093/carcin/17.10.2119
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发表时间：
1996
期刊：
影响因子：
4.7
通讯作者：
Ruch,RJ
中科院分区：
文献类型：
--
作者：
Ren,P;Ruch,RJ
某些巴比妥类化合物可促进啮齿动物肝脏肿瘤的形成，这可能与其抑制肝细胞缝隙连接细胞间通讯(GJIC)的能力有关。为了探讨巴比妥酸盐对肝细胞缝隙连接作用的机制和特异性，我们比较了促肝肿瘤的巴比妥酸盐(苯巴比妥、巴比妥钠和阿巴比妥分别为PB、SB和AB)和非促肝肿瘤的巴比妥酸(巴比妥酸：BA)在短时间(1-24小时)和长时间(2-14天)处理大鼠肝细胞后对GJIC和连接蛋白32(Cx32)表达的影响；在地塞米松存在下，WB-F344大鼠肝上皮细胞与WB-F344细胞共培养14天后，这两个参数都保持在高水平。用PB(2 MM)处理1h后，∼90-30%的染料偶联率显著降低，但细胞在24 h后完全恢复，其他巴比妥类药物在这1天的处理时间内未见抑制作用。然而，用促进剂PB、SB和AB进行较长时间的处理(2-14天)后，肝细胞对∼的染料偶联程度逐渐减少30-50%。非启动子BA不影响肝细胞GJIC。这些肝细胞染料偶联的减少发生在没有改变Cx32或缝隙连接表达的情况下。WB-F344细胞的染料偶联及其主要缝隙连接蛋白Cx43的表达也没有受到影响。因此，GJIC的抑制作用是针对促进肝细胞中巴比妥酸盐的肝肿瘤的，是时间依赖的，而不是由于Cx32表达的改变。
Rodent liver tumor formation can be promoted by certain barbiturates and this may involve their ability to inhibit hepatocyte gap junctional intercellular communication (GJIC). In order to address the mechanisms and specificity of action of barbiturates on hepatocyte gap junctions, we have compared the effects of liver tumor-promoting barbiturates (phenobarbital, sodium barbital and amobar-bital: PB, SB and AB, respectively) and a non-liver tumor-promoting barbiturate (barbituric acid: BA) on primary cultured rat hepatocyte GJIC and connexin32 (Cx32) expression after short (1–24 h) and long (2–14 days) treatment GJIC was evaluated by fluorescent dye microin-jection (dye-coupling); Cx32 expression was monitored by Northern blot, Western blot and immunohistochemistry. Both parameters were maintained at high levels over 14 days by coculture of the cells with WB-F344 rat liver epithelial cells in the presence of dexamethasone. Treatment with PB (2 mM) for 1 h sharply reduced dye-coupling from ∼90–30%, but the cells fully recovered by 24 h. No inhibition was seen with the other barbiturates over this 1-day treatment period. Longer treatments (2–14 days) with the promoters PB, SB and AB, however, gradually reduced hepatocyte dye-coupling to ∼30–50%. The non-promoter, BA, did not affect hepatocyte GJIC. These decreases in hepatocyte dye-coupling occurred without changes in Cx32 or gap junction expression. Dye-coupling of WB-F344 cells and expression of their predominant gap junction protein, connexin43 (Cx43), were also not affected. Thus, the inhibition of GJIC was specific to liver tumor promoting barbiturates in hepatocytes, was time-dependent and was not due to altered Cx32 expression.