摘要
目的探讨G蛋白偶联受体激酶2/3(GRK2/3)在大鼠下丘脑室旁核促肾上腺皮质激素释放激素(CRH)分泌调节中的作用。方法采用10nM CRH刺激离体培养的大鼠下丘脑脑片,对该离体模型进行研究。通过Western blot实验研究室旁核GRK2/3的蛋白表达,逆转录多聚酶链反应(RT-PCR)技术研究室旁核CRH的转录活性。结果10nM CRH刺激30min、60min可引起CRHmRNA表达非常显著地增强(P<0.01);而GRK2/3总蛋白在刺激30min后非常显著地下降(P<0.01),60min后仍显著低于对照(P<0.05)。提前给予GRK的拮抗剂肝素1μM,处理2h可非常显著地抑制GRK2/3蛋白的表达(P<0.01);同时非常显著地增加CRHmRNA的表达(P<0.01)。提前给予钙调蛋白(CaM)的特异性拮抗剂W-750μM,处理2h可非常显著抑制CRH刺激30min引起的GRK2/3蛋白含量减少(P<0.01);同时非常显著地抑制CRH mRNA含量(P<0.01)。结论应激早期下丘脑室旁核GRK2/3在CRH分泌调节中作用不明显。这可能与该阶段CaM增加,抑制GRK2/3的蛋白表达,削弱其对CRHR1的脱敏作用有关。
Objective To study effect of G protein-coupled recepter kinase 2/3 （GRK 2/3 ） on the regulation of cortieotrophin-releasing hormone （ CRH ） secretion in hypothalamie paraventricular nucleus （ PVN ） of rats. Methods The in vitro model whose cultured hypothalamic brain slices was given with 10 nM CRH was studied in rals. The GRK 2/3 and the mRN ／ of CRH were measured by Westem blot and reverse transeriptional polymerase chain reaction （RT-PCR） respectively. Results In the cuhured hypothalamus slices, 10 nM CRH given for 30 min, 60 min could stimulate the increase of CRH mRNA （ P 〈0.01 ）. However, a very significant decrease of GRK 2/3 was measured after CRH exposure for 30min （ P 〈 0. 01 ） and marked attenuation after exposure for 60 min （P 〈0.05 ）. A total of 1 μM heparin, the nonselective GRK inhibitor, preincubation for 2 h could increase the CRH mRNA siguificantly（ P 〈 0. 01 ）. A total of 50 μM W-7, cahnodulin （CaM） specifieal antagonist, incubation for 2 h could reverse the inhibition of CRH on GRK 2/3 and attenuate CRH mRNA notably （ P 〈 0.01 ）. Conclusion GRK 2/3 does not play a key role in the seeretion of CRH in PVN of rats. This may give rise to the upgrow of CaM at the same time, which inhibits expression of GRK 2/3 protein and deprives its role in the desensitization of conticotrophin-releasing hormone recepter 1 （CRHR 1 ）.
出处
《中华神经外科疾病研究杂志》
CAS
2005年第5期411-414,共4页
Chinese Journal of Neurosurgical Disease Research
基金
国家"973"创伤基金资助项目(G1999054201)
