Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Protein kinase A-dependent Neuronal Nitric Oxide Synthase Activation Mediates the Enhancement of Baroreflex Response by Adrenomedullin in the Nucleus Tractus Solitarii of Rats | Yen et al. Journal of Biomedical Science 2011 18 32 http www.jbiomedsci.eom content 18 1 32 tì.NSC The cost of publication in Journal of Biomedical Science Is borne by the National Science Council Taiwan JOURNAL OF BIOMEDICAL SCIENCE RESEARCH Open Access Protein kinase A-dependent Neuronal Nitric Oxide Synthase Activation Mediates the Enhancement of Baroreflex Response by Adrenomedullin in the Nucleus Tractus Solitarii of Rats David HT Yen1 2t Lih-Chi Chen3t Yuh-Chiang Shen4 Ying-Chen Chiu5 I-Chun Ho5 Ya-Jou Lou 3 I-Chin Chen3 and Jiin-Cherng Yen3 5 Abstract Background Adrenomedullin ADM exerts its biological functions through the receptor-mediated enzymatic mechanisms that involve protein kinase A PKA or neuronal nitric oxide synthase nNOS . We previously demonstrated that the receptor-mediated cAMP PKA pathway involves in ADM-enhanced baroreceptor reflex BRR response. It remains unclear whether ADM may enhance BRR response via activation of nNOS-dependent mechanism in the nucleus tractus solitarii NTS . Methods Intravenous injection of phenylephrine was administered to evoke the BRR before and at 10 30 and 60 min after microinjection of the test agents into NTS of Sprague-Dawley rats. Western blotting analysis was used to measure the level and phosphorylation of proteins that involved in BRR-enhancing effects of ADM 0.2 pmol in NTS. The colocalization of PKA and nNOS was examined by immunohistochemical staining and observed with a laser confocal microscope. Results We found that ADM-induced enhancement of BRR response was blunted by microinjection of NPLA or Rp-8-Br-cGMP a selective inhibitor of nNOS or protein kinase G PKG respectively into NTS. Western blot analysis further revealed that ADM induced an increase in the protein level of PKG-I which could be attenuated by co-microinjection with the ADM receptor antagonist ADM22-52 or NPLA. Moreover we observed an increase in phosphorylation at Ser1416 of nNOS at 10 30 and 60 min after intra-NTS administration of .