钙调神经磷酸酶在逼尿肌肥大发生中的作用研究

Effect of calcineurin in hypertrophy of detrusor muscle

目的观察钙调神经磷酸酶(CaN)催化亚单位α、β、γ(CnAα、CnAβ、CnAγ)3种亚型在肥大逼尿肌的表达变化,探讨其在逼尿肌肥大发生中的作用。方法选用10周龄雌性W istar大鼠实行膀胱出口部分梗阻手术。手术分别于2、4、6周取下大鼠膀胱。以RT-PCR检测3种亚型mRNA表达,W estern b lot测定亚型蛋白表达量的变化。肥大标志物肌球蛋白重链(MHC)表达变化通过考马斯亮蓝胶染色光密度测定。结果①RT-PCR可检测到CnAα、CnAβ,未检测到CnAγ。②W estern b lot检测,CnAα手术后2周比对照组表达显著增加(P<0.01),4周、6周表达下降。CnAβ表达无显著变化。③肌球蛋白重链表达变化与CnAα表达变化具有相关性。结论CnAα在逼尿肌肥大发生中起重要的作用,CnAβ作用不明显。

Objective To explore the regulatory role of calcineurin （CaN） in the hypertrophy of detrusor cells and investigate the difference of the expression of CnAα, CnAβ, CnAγ in the hypertrophic detrusor cells. Methods Partial bladder outlet obstruction （BOO） was surgically induced in thirty 10-week-old female Wistar rats. The bladder was excised 2, 4 and 6 weeks respectively after BOO. Another 10 rats as control underwent sham operation and 2 weeks later the bladder was subjected to experiment. The mRNA and protein expression of calcineurin subunit α, β, γ （CnAα, CnAβ, CnAγ） was examined respectively by RT-PCR and Western blotting. Myosin heavy chain expression was evaluated on gels stained with Coomassie blue. Results CnAα, CnAβ could be detected by RT-PCR but no CnAγ. CnAα expression increased 2 weeks after BOO as compared to that of controls （ P 〈 0.01 ）, decreased during 4 and 6 weeks. However, CnAβ expression showed no change throughout the development of hypertrophy. The changes in myosin heavy chain expression correlated with CnAet expression. Conclusion This experiment suggests that CnAα not CnAβ play an important role in the formation of bladder smooth muscle hypertrophy.