رسالة جامعية
Role of sympathetic α3β2-nAChRs in neurogenic control of cerebrovascular tone
| العنوان: | Role of sympathetic α3β2-nAChRs in neurogenic control of cerebrovascular tone |
|---|---|
| العنوان البديل: | α3β2-尼古丁受體在豬之神經性腦血管舒縮所扮演的角色 |
| المؤلفون: | Reggie Hui-Chao Lee, 李慧超 |
| مرشدي الرسالة: | Tony Jer-Fu Lee, 李哲夫 |
| سنة النشر: | 2012 |
| المجموعة: | National Digital Library of Theses and Dissertations in Taiwan |
| الوصف: | 100 Background and purpose: The α7-nicotinic acetylcholine receptor (α7-nAChR) on sympathetic neurons innervating basilar arteries of pigs crossed breed between Landrace and Yorkshire (LY) is known to mediate nicotine-induced, β-amyloid (Aβ)-sensitive nitrergic neurogenic vasodilation. Preliminary studies, however, demonstrated that nicotine-induced cerebral vasodilation in pigs crossbreed among Landrace, Yorkshire and Duroc (LYD) was insensitive to Aβ and α-bungarotoxin (α-BGTX). We investigated nAChR subtype on sympathetic neurons innervating LYD basilar arteries. Experimental approach: Nicotine-induced relaxation of isolated porcine basilar arteries was examined by tissue bath myography, inward currents on nAChR-expressing oocytes by two-electrode voltage recording, and mRNA and protein expression in the superior cervical ganglion (SCG), and middle cervical ganglion (MCG) by reverse transcription PCR and western blotting. Key results: Nicotine-induced basilar arterial relaxation was not affected by Aβ, α-BGTX and α-conotoxin IMI (α7-nAChR antagonists), or α-conotoxin AuIB (α3β4-nAChR antagonist), but was inhibited by tropinone and tropane (α3-containing nAChR antagonists), and α-conotoxin MII (selective α3β2-nAChR antagonist). Nicotine-induced inward currents in α3β2-nAChR-expressing oocytes were inhibited by α-conotoxin MII but not by α-BGTX, Aβ, or α-conotoxin AuIB. mRNAs of α3-, α7-, β2- and β4-subunits were expressed in both SCGs and MCGs. The mRNAs of α3-, β2- and β4-subunits were significantly higher than those of α7-subunit. Conclusions and implications: The Aβ-insensitive sympathetic α3β2-nAChR mediates nicotine-induced cerebral nitrergic neurogenic vasodilation in LYD pigs. The different finding from Aβ-sensitive α7-nAChR in basilar arteries of LY Pigs may offer a partial explanation for different sensitivities of individuals to Aβ in causing diminished cerebral nitrergic vasodilation in diseases involving Aβ. |
| Original Identifier: | 100TCU05659003 |
| نوع الوثيقة: | 學位論文 ; thesis |
| وصف الملف: | 122 |
| الإتاحة: | http://ndltd.ncl.edu.tw/handle/8rey96Test |
| رقم الانضمام: | edsndl.TW.100TCU05659003 |
| قاعدة البيانات: | Networked Digital Library of Theses & Dissertations |
| الوصف غير متاح. |