کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2007097 | 1066363 | 2009 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Acute modulation of myocardial function by angiotensin 1-7
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Angiotensin 1-7 is a bioactive heptapeptide of the renin-angiotensin system. Its cardiovascular actions have recently acquired growing relevance, mainly due to its counter-regulatory actions in the angiotensin cascade. The aim of the present study was to evaluate the actions of angiotensin 1-7 on myocardial function. Increasing concentrations of angiotensin 1-7 (10â9 to 10â5 M) were added to rabbit right papillary muscles: (1) in baseline conditions with intact endocardial endothelium (EE); (2) after selective removal of the EE with Triton X-100 (1 s, 0.01%); (3) with intact EE in the presence of the Mas receptor antagonist A-779, the AT1 receptor antagonist ZD-7155, the AT2 receptor antagonist PD-123,319 or the nitric oxide synthesis inhibitor NG-nitro-l-arginine (l-NA). Concerning the effects on contractility, we observed a significant decrease on active tension, dT/dtmax, peak shortening and dL/dtmax of â10.5 ± 3.6%, â8.0 ± 3.0%, â5.3 ± 2.6% and â5.7 ± 2.3%, respectively. There was no change on relaxation parameters, namely dT/dtmin or dL/dtmin. Time to half relaxation was significantly decreased. The presence of ZD-7155 or PD-123,319 did not change these effects. However, angiotensin 1-7 effects on myocardial properties were abolished after selective EE removal and in the presence of A-779 or l-NA. In conclusion, in this animal species, angiotensin 1-7 through its binding to Mas receptor induces a negative inotropic effect modulated by the EE and nitric oxide and independent of AT1 or AT2 receptors activation. As the effects described in the present work were influenced by the endocardial endothelium, they may be disrupted in situations associated to endothelial dysfunction, as in heart failure or myocardial ischemia.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Peptides - Volume 30, Issue 9, September 2009, Pages 1714-1719
Journal: Peptides - Volume 30, Issue 9, September 2009, Pages 1714-1719
نویسندگان
Paulo Castro-Chaves, Mariana Pintalhao, Ricardo Fontes-Carvalho, Rui Cerqueira, Adelino F. Leite-Moreira,