Evidence that rat hepatocytes co-express functional P2Y1 and P2Y2 receptors
Evidence that rat hepatocytes co-express functional P2Y1 and P2Y2 receptors
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DOI：
10.1038/sj.bjp.0703103
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发表时间：
2000-02-01
影响因子：
7.3
通讯作者：
Green, AK
中科院分区：
文献类型：
--
作者：
Dixon, CJ;Woods, NM;Green, AK
1已有研究表明大鼠肝细胞表达多种P2Y受体，但尚未被鉴定。逆转录聚合酶链式反应(RT-PCR)显示大鼠肝细胞表达四种克隆的大鼠P2Y受体(P2Y(1)、P2Y(2)、P2Y(4)和P2Y(6))的mRNA。在同一细胞内，UTP诱导的[Ca~(2+)](I)瞬变与ATP诱导的[Ca~(2+)](I)瞬变无明显区别。细胞内环磷酸腺苷浓度升高对UTP和ATP诱导的[Ca~(2+)](I)瞬变的调制作用是相同的。3用P2Y(6)受体激动剂UDP来诱导肝细胞瞬变，表明与升高的[Ca~(2+)](I)偶联的功能性P2Y(6)受体不表达。4 ADP引起的瞬变对苏拉明的抑制比由ATP或UTP诱导的更敏感。在单个细胞内，相同浓度的苏拉明可抑制ATP和UTP诱导的瞬变。苏拉明对ATP和UTP反应的这种敏感性表明，这种作用是通过P2Y(2)而不是P2Y(4)受体起作用的。5联合应用30muM pyridoxalphosphate-6-azophenyl-2‘，4’-disulphonic酸(PPADS)可降低由腺苷二磷酸诱导的瞬变的频率和幅度。加入PPADS后，ATP和UTP诱导的瞬变反应也表现出幅度降低，但伴随着瞬变频率的增加。6结论：本文提供的数据与大鼠肝细胞共表达P2Y(1)和P2Y(2)受体是一致的。
1 Previous studies have indicated the expression of multiple P2Y receptors by rat hepatocytes although they have nor been identified. Here we show by reverse transcriptase-polymerase chain reaction (RT-PCR) that rat hepatocytes express mRNA encoding all of the four cloned rat P2Y receptors (P2Y(1), P2Y(2), P2Y(4) and P2Y(6)).2 The effects of UTP have been examined on single aequorin-injected rat hepatocytes. The [Ca2+](i) transients induced by UTP were indistinguishable from those induced by ATP in the same cell. The modulatory effects of elevated intracellular cyclic AMP concentration were the same on both UTP- and ATP-induced [Ca2+](i) transients.3 UDP, an agonist at the P2Y(6) receptor, filled to induce transients in hepatocytes, indicating that functional P2Y(6) receptors coupled to increased [Ca2+](i) are not expressed.4 The transients evoked by ADP were more sensitive to inhibition by suramin than those induced by either ATP or UTP. Within an individual cell, the transients induced by ATP and UTP were inhibited by the same concentration of suramin. This sensitivity of ATP and UTP responses to suramin suggests action through P2Y(2) rather than P2Y(4) receptors.5 Co-application of 30 mu M pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) caused a decrease in frequency and amplitude of transients induced by ADP. ATP- and UTP-induced transients also displayed a decrease in amplitude in response to addition of PPADS, but this was accompanied by an increase in frequency of transients.6 In conclusion the data presented here are consistent with the co-expression of P2Y(1) and P2Y(2) receptors by rat hepatocytes.