【摘要】 目的 研究心房颤动发生时B型利钠肽受体(NPR-B)、颗粒性膜结合鸟苷酸环化酶(PGC)、环磷酸鸟苷(cGMP)改变及发生机制。方法 40只白兔随机分为5组：对照组、快速心房起搏(RAP)1 h组、RAP 2 h组、RAP 4 h组、RAP 8 h组，每组8只，对照组只置入电极不进行心房电刺激。分别用放射免疫实验和ELISA检测各组血浆心房钠尿肽(ANP)和cGMP表达，Western blot检测心房NPR-B表达。实验结束后，取对照组和RAP 8 h组心房进行灌流实验。结果 与对照组比较，RAP 1 h组、RAP 2 h组、RAP 4 h组、RAP 8 h组血浆ANP和RAP 1 h组cGMP水平升高，RAP 8 h组cGMP水平降低(P<0.05,P<0.01),RAP 1 h组、RAP 2 h组、RAP 4 h组、RAP 8 h组心房组织NPR-B蛋白表达无明显变化(0.88±0.08,0.90±0.08,0.88±0.11,0.82±0.09 vs 0.85±0.05,P>0.05)。有C型钠尿肽时，RAP 2 h组、RAP 4 h组、RAP 8 h组PGC活性明显低于对照组(P<0.05,P<0.01)。灌流实验显示，RAP 1 h组、RAP 2 h组、RAP 4 h组、RAP 8 h组心房组织对C型钠尿肽的敏感性较对照组降低。结论 心房颤动发生时NPR-B对ANP敏感性降低，导致PGC活性降低，进而引起cGMP生成减少。更多还原

【Abstract】 Objective To study the changes in NPR-B-PGC-cGMP signaling pathway during atrial fibrillation and investigate the underlying mechanism in the occurrence.Methods 40 white rabbits were randomly divided into control group, RAP 1,2,4,and 8 h groups, respectively(n=8).The rabbits from the control group were implanted with electrodes.The expression and contents of ANP and cGMP were detected by radioimmunoassay and ELISA.The atrial expression of NPR-B was detected by Western blotting.The atrium from the control and RAP 8 h group were isolated for atrial perfusion test.Results In vivo, when compared with the control group, the plasma ANP level was higher in the 4 RAP groups increased(P<0.05),while the cGMP level was increased first(the RAP 1 h group) and then decreased with the elongation of stimulation, and finally(the RAP 8 h group),the level was lower than that of the control group(P<0.05,P<0.01).There were no significant differences in the expression level of NPR-B in the RAP 1 h, 2 h, 4 h and 8 h groups when compared with the control group(0.88±0.08,0.90±0.08,0.88±0.11,0.82±0.09 vs 0.85±0.05,P>0.05).In the presense of CNP,the activity of PGC was obviously lower in the RAP 2 h, 4 h and 8 h groups than the control group(P<0.05,P<0.01).Atrial perfusion test showed that the atrial tissue exhibited lower sensitivity to CNP in the 4 RAP groups than the control group.Conclusion When atrial fibrillation occurs, NPR-B is less sensitive to ANP,which resulting in reduced PGC activity and thus reduced cGMP production.更多还原