摘要
目的探讨2型糖尿病大鼠随着病程发展,膀胱舒张功能及逼尿肌细胞β受体的变化。方法①运用离体逼尿肌肌条机械牵张刺激实验,以β受体激动剂异丙肾上腺素(ISO),在不同药物浓度(1×10-9~3×10-5)刺激逼尿肌肌条,观察糖尿病大鼠与正常大鼠在不同时期的舒张力变化。②在不同时间段,消化逼尿肌细胞,用流式细胞学方法检测逼尿肌细胞膜上β3受体的变化。③制备膀胱匀浆,用蛋白印迹法方法检测G蛋白亚型在各时间段的变化。结果①不同浓度ISO刺激逼尿肌肌条的机械性牵张刺激实验研究发现:8周时,半数计量有效浓度(IC50)糖尿病组比对照组敏感(P<0.05),对照组最大舒张力Emax比糖尿病组小,差异有统计学意义(P<0.01)。16周时,IC50对照组比实验组敏感(P<0.01),糖尿病组最大舒张力Emax降低(P<0.05);24周时,IC50对照组比糖尿病组敏感(P<0.01),糖尿病组Emax明显降低(P<0.01)。②采用流式细胞学方法检测逼尿肌细胞上β3受体密度发现,8周时糖尿病组与对照组相比增加,差异有统计学意义(P<0.05);16周时,糖尿病组β3受体平均荧光强度比正常对照组降低(P<0.05);24周时,糖尿病组与对照组β3受体平均荧光强度相比显著下降(P<0.01)。结论糖尿病大鼠逼尿肌舒张功能在病程前期表现为舒张力增强,对ISO敏感增强,相比较同期β3受体含量糖尿病组增高。
Objective To investigate the changes in relaxation capacity and expression of β receptors,as with the advanced disease severity,in rats with type 2 diabetes mellitus.Methods Detrusor strips,when stimulated in vitro by isoprenaline,a β receptor,at increasing concentrations(1×10^-9~3×10^-5),were employed to conduct the contraction/relaxation test.This may allow the determination of the changes in contractility at various time points in rats with diabetes mellitus(DM) and normal controls.Flow cytometry was adopted to examine the alteration in β3 receptors on the cellular membrane following digestion of detrusor cells.The cells of bladder were homogenized for subsequent assessment of the changes in G protein subtypes at various time points by Western blotting.Results In the current study where detrusor strips were subjected to isoprenaline stimulation at various concentrations,rats with DM were associated with a lower half maximal inhibitory concentration(IC50) yet higher maximal distention(Emax) when compared with normal controls at week 8(P〈0.05 and 0.01,respectively).An opposite trend was noted at week 16(P〈0.01 and 0.05,respectively).A lower IC50 and profoundly reduced Emax were found in rats with DM at week 24(both P〈0.01).At week 8,rats with DM yielded increased expression of β3 receptors on the cellular membrane(P〈0.05).However,suppression of β3 receptor expression was noted at week 16 when compared with that of normal controls(P〈0.05),as suggested by the intensity of fluorescence.The reduction in β3 receptor expression in rats with DM was further aggravated at week 24(P〈0.01).Conclusion Increased relaxation capacity is associated with a higher sensitivity to isoprenaline at the early stage of disease in rats with DM,the results that coincided with raised,but not suppressed,β3 receptor expression in the detrusor that could have stemmed from compensation.The advance of disease severity may result in suppressed β3 receptor expression leading to aberrant signaling transmission and decreased relaxation capacity of detrusor.
出处
《中国药物与临床》
CAS
2013年第1期12-14,共3页
Chinese Remedies & Clinics
基金
山西省回国留学人员科技项目(2007-47)
人事部留学人员择优资助项目(晋人函字[2009]3号)
山西省人事厅留学人员科技活动项目(晋人专函[2009]1号)
关键词
糖尿病
2型
膀胱
Β受体
逼尿肌
舒张功能
Diabetes mellitus
type 2
Bladder
β-receptor
Detrusor
Relaxation function