Hepatocanalicular organic-anion transport is regulated by protein kinase C.
Hepatocanalicular organic-anion transport is regulated by protein kinase C.
复制标题
肝小管有机阴离子转运受蛋白激酶 C 调节。
作者：
Han Roelofsen;R. Ottenhoff;R. Elferink;Plm Jansen
为了研究小管有机阴离子转运的调节，我们采用肝细胞转运实验，在钙离子/蛋白激酶C(PKC)第二信使系统和环磷酸腺苷(CAMP)第二信使系统的刺激剂和抑制剂存在的情况下，测量了模型有机阴离子GS-DNP的小管分泌量。PKC的激动剂加压素(24 NM)和佛波酯(1微克/毫升)分别刺激GS-DNP外流65+/-36%和55+/-28%，而PKC的抑制剂星形孢子素(10微米)则抑制53+/-13%的外流。CAMP第二信使系统的刺激物胰高血糖素和Forsklin以及cAMP类似物二丁酰cAMP和磷酸二酯酶抑制剂3-异丁基-1-甲基黄嘌呤对GS-DNP的外流无明显影响。结论：肝细胞小管有机阴离子转运直接或间接受PKC的调节。
In order to investigate the regulation of canalicular organic-anion transport, we used a hepatocyte transport assay in which canalicular secretion of a model organic anion, dinitrophenyl-glutathione (GS-DNP), was measured in the presence of stimulators and inhibitors of the Ca2+/protein kinase C (PKC) second-messenger system and of the cyclic AMP (cAMP) second-messenger system. Vasopressin (24 nM) and the phorbol ester phorbol 12-myristate 13-acetate (1 microgram/ml), both stimulators of PKC, stimulated GS-DNP efflux by 65 +/- 36% and 55 +/- 28% respectively, whereas staurosporine (10 microM), an inhibitor of PKC, inhibited efflux by 53 +/- 13%. Glucagon and forskolin, both stimulators of the cAMP second-messenger system, as well as the cAMP analogue dibutyryl cAMP and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine, did not significantly influence the GS-DNP efflux. It can be concluded that canalicular organic-anion transport in hepatocytes is either directly or indirectly regulated by PKC.