Prolactin increases mRNA encoding Na(+)-TC cotransport polypeptide and hepatic Na(+)-TC cotransport.
Prolactin increases mRNA encoding Na(+)-TC cotransport polypeptide and hepatic Na(+)-TC cotransport.
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催乳素增加编码 Na()-TC 共转运多肽和肝 Na()-TC 共转运的 mRNA。
DOI：
10.1152/ajpgi.1995.268.1.g11
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Vore,M
中科院分区：
文献类型：
--
作者：
Liu,Y;Ganguly,T;Hyde,JF;Vore,M
我们已经表明，催乳素（Prl）增加牛磺胆酸（TC）在产后大鼠和以下的治疗卵巢切除（OVX）大鼠与绵羊Prl（oPrl）的transsheeton运输。本研究旨在确定用oPrl治疗Ovx大鼠是否（100、300或600微克/天，7天iv）1）增加基底外侧质膜囊泡（bLPM）中的Na（+）-TC共转运，2）诱导Na（+）-TC共转运多肽稳态水平的相应增加（Ntcp mRNA），和3）如果oPrl介导的Na（+）-TC共转运活性的增加被蛋白质合成抑制剂放线菌酮阻断。oPrl（300 μ g/天）诱导肝细胞和bLPM囊泡中Na（+）-TC共转运的最大速度增加两倍，米氏常数几乎没有变化。以100、300或600微克/天的剂量输注oPrl分别使稳态Ntcp mRNA增加4倍、10倍和2倍。最后，放线菌酮阻断oPrl介导的Na（+）-TC共转运增加，但不影响基础活性。这些数据支持以下假设：Ntcp mRNA增加，随后Ntcp合成增加并掺入质膜，是oPrl介导的肝细胞基底外侧质膜域Na（+）-TC共转运增加的原因。
We have shown that prolactin (Prl) increases the transhepatic transport of taurocholate (TC) in postpartum rats and following treatment of ovariectomized (Ovx) rats with ovine Prl (oPrl). The present studies were designed to determine if treatment of Ovx rats with oPrl (100, 300, or 600 micrograms/day, 7 days iv) 1) increases Na(+)-TC cotransport in basolateral plasma membrane vesicles (bLPM), 2) induces a corresponding increase in the steady-state levels of Na(+)-TC cotransport polypeptide (Ntcp mRNA), and 3) if the oPrl-mediated increase in Na(+)-TC cotransport activity is blocked by cycloheximide, an inhibitor of protein synthesis. oPrl (300 micrograms/day) induced a twofold increase in the maximal velocity for Na(+)-TC cotransport in both hepatocytes and bLPM vesicles with little change in the Michaelis constant. Infusion of oPrl at a dose of 100, 300, or 600 micrograms/day increased steady-state Ntcp mRNA four-, ten-, and twofold, respectively. Finally, cycloheximide blocked the oPrl-mediated increase in Na(+)-TC cotransport but did not affect basal activity. These data support the hypothesis that an increase in Ntcp mRNA followed by increased synthesis and incorporation of Ntcp in the plasma membrane is responsible for the oPrl-mediated increase in Na(+)-TC cotransport in the basolateral plasma membrane domain of the hepatocyte.