C-type natriuretic-peptide-potentiated relaxation response of gastric smooth muscle in streptozotocin-induced diabetic rats
C-type natriuretic-peptide-potentiated relaxation response of gastric smooth muscle in streptozotocin-induced diabetic rats
复制标题
C型利钠肽增强链脲佐菌素诱导的糖尿病大鼠胃平滑肌的松弛反应。
DOI：
10.3748/wjg.15.2125
复制
发表时间：
2009-05-07
影响因子：
4.3
通讯作者：
Xu, Wen-Xie
中科院分区：
文献类型：
--
作者：
Cai, Ying-Lan;Xu, Dong-Yuan;Xu, Wen-Xie
目的：研究链脲佐菌素（STZ）诱导的糖尿病大鼠胃平滑肌对c型利钠肽（CNP）的敏感性。方法：采用生理方法记录大鼠胃平滑肌条的自发收缩。应用免疫组化技术检测糖尿病大鼠胃组织中CNP和利钠肽受体b （NPR-B）的表达。结果：注射STZ和对照药后4周，糖尿病大鼠胃平滑肌自发收缩频率明显降低，由对照组的3.10 +/- 0.14周期/min降至2.23 +/- 0.13周期/min （n = 8, P < 0.01）。自发性收缩幅度与正常大鼠无显著性差异。CNP对正常大鼠和糖尿病大鼠胃平滑肌自发收缩有明显抑制作用，对糖尿病大鼠胃平滑肌自发收缩的抑制作用明显增强。糖尿病大鼠和正常大鼠自发性收缩的幅度分别下降75.15% +/- 0.71%和58.92% +/- 1.32%，频率分别下降53.33% +/- 2.03%和26.95% +/- 2.82% （n = 8, P < 0.01）。糖尿病大鼠胃组织中CNP的表达无变化，而胃组织中NPR-B的表达明显升高，NPR-B在糖尿病大鼠和正常大鼠的染色指数分别为30.67 +/- 1.59和17.63 +/- 1.49 （n = 8, P < 0.01）。结论：CNP对糖尿病大鼠胃平滑肌自发收缩具有抑制作用，这种抑制作用通过上调利钠肽- pr - b -颗粒基环化酶-环GMP信号通路而增强。(C) 2009 WIG出版社、白石登出版社。版权所有。
AIM: To study the sensitivity of gastric smooth muscle to C-type natriuretic peptide (CNP) in streptozotocin (STZ)-induced diabetic rats.METHODS: The spontaneous contraction of a gastric smooth muscle strip was recorded by using physiological methods in rats. The expressions of CNP and natriuretic peptide receptor-B (NPR-B) in gastric tissue were examined by using immunohistochemistry techniques in the diabetic rat.RESULTS: At 4 wk after injection of STZ and vehicle, the frequency of spontaneous contraction of gastric smooth muscle was significantly reduced in diabetic rats, and the frequency was decreased from 3.10 +/- 0.14 cycle/min in controls to 2.23 +/- 0.13 cycle/min (n = 8, P < 0.01). However, the amplitude of spontaneous contraction was not significant different from the normal rat. CNP significantly inhibited spontaneous contraction of gastric smooth muscle in normal and diabetic rats, but the inhibitory effect was significantly potentiated in the diabetic rats. The amplitudes of spontaneous contraction were suppressed by 75.15% +/- 0.71% and 58.92% +/- 1.32% while the frequencies were decreased by 53.33% +/- 2.03% and 26.95% +/- 2.82% in diabetic and normal rats, respectively (n = 8, P < 0.01). The expression of CNP in gastric tissue was not changed in diabetic rats, however the expression of NPR-B was significantly increased in diabetic rats, and the staining indexes of NPR-B were 30.67 +/- 1.59 and 17.63 +/- 1.49 in diabetic and normal rat, respectively (n = 8, P < 0.01).CONCLUSION: The results suggest that CNP induced an inhibitory effect on spontaneous contraction of gastric smooth muscle, potentiated in diabetic rat via up-regulation of the natriuretic peptides-NPR-B-particulate guanylyl cyclase-cyclic GMP signal pathway. (C) 2009 The WIG Press and Baishideng. All rights reserved.