- 作者: Alice Y.W. Chang Julie Y.H. Chan Samuel H.H. Chan
- 作者服務機構: Center for Neuroscience and Department of Biological Science, National Sun Yat-sen University, Department of Medical Education and Research, Kaohsiung Veterans Genral Hospital, Kaohsiung, Taiwan, ROC
- 中文摘要: --
- 英文摘要: We evaluated the distribution of nitric oxide synthase(NOS) isoforms in the rostral ventrolateral medulla(RVLM), the medullary origin of sympathetic neurogenicvasomotor tone, and the contribution of NOS III to thecardiovascular actions of endogenous NO in the RVLM.Adult Sprague-Dawley rats were used. Reverse tran-scription-polymerase chain reaction or Western blotanalysis revealed that NOS I, II or III was expressed in theventrolateral medulla at the mRNA or protein level underbasal conditions. However, laser scanning confocalmicroscopic analysis of double-immunofluorescenceimages showed that whereas NOS I or II immunoreactiv-ity colocalized with cells within the confines of the RVLMthat stained positively with the neuronal marker, NeuN,NOS III immunoreactivity was associated primarily withblood vessels. Furthermore, bilateral microinjection intothe RVLM of the selective NOS III inhibitor, N -(1-imino-ethyl)-L-ornithine, elicited minimal alterations in base-line systemic arterial pressure, heart rate or sympatheticvasomotor outflow in rats anesthetized with propofol.We conclude that whereas NOS I and II are present inneurons within the confines of the RVLM, NOS III is asso-ciated primarily with blood vessels. Our results furtherindicate that NOS III does not appear to contribute to themaintenance of basal sympathetic vasomotor outflowsand arterial pressure by the endogenous NO at theRVLM.
- 中文關鍵字: --
- 英文關鍵字: Nitric oxide synthase I, II, III. Rostral ventrolateral medulla. Cardiovascular regulation. Sympathetic premotor neurons