目的 建立不同间歇低氧/再氧合(IH/ROX)模式家兔颈动脉体在体模型,探讨不同频率IH/ROX暴露后家兔颈动脉体的炎症状态、内皮素水平和颈动脉体窦神经传入活性. 方法 49只成年雄性大耳白家兔(2.5～3.0 kg)分为7组,每组7只,分离右侧颈总动脉和右窦神经,窦神经去包膜显露髓鞘,游离化学感受性神经细束记录窦神经传入活性.结扎近心端,远心端内插入导管,经程控蠕动泵交替灌注以发泡法预平衡的低氧灌注液和(或)正常氧灌注液,在右侧颈总动脉内模拟睡眠呼吸暂停模式IH/ROX暴露条件或持续低氧条件.按灌注频率分组为:间歇正常氧组(21%0:,15 s;21%02,1 min 45 s)、10次/h组(21%02,5 min 45 s)、30次/h组(21%02,1 min 45 s)、50次/h组(21%02,57 s)、60次/h组(21%02,45 s)、90次/h组(21%02,25 s),均反复灌注60次;持续低氧组:间歇正常灌注1 h 45 min,随后给予5%O2持续15 min.静置30 min,采集窦神经传入活性频率(Charge F),游离收集右侧颈动脉体,酶联免疫吸附法(ELISA法)测定颈动脉体裂解液中白细胞介素-6(IL-6)、内皮素-1、低氧诱导因子-1(HIF-1)和血管内皮生长因子(VEGF)浓度并标准化.整体比较时采用单因素方差分析,配对比较用Tamhane T2法. 结果 随着间歇正常氧频率增加,IL-6、内皮素-1和Charge F整体均数呈现出先升后降趋势(F=25 601.39,2390.48,6945.84,均P＜0.05),50/hr组IL-6、内皮素-1和Charge F水平均高于其余各组.且Charge F与IL-6和内皮素-1相关(r=0.736,0.757,均P＜0.05);而组间IL-6、内皮素-1和Charge F水平差异不明显.随着间歇低氧频率增加,HIF-1水平逐渐增加(F=5241.10,P＜0.01),持续低氧组HIF-1水平最高.VEGF水平呈现出先升后降再升趋势(F=5931.30,P＜0.05),持续低氧组VEGF水平增加最明显. 结论 IH/ROX暴露后颈动脉体窦神经传入活性明显增强并与颈动脉体炎症和血管收缩密切相关,颈动脉体的炎症来源于再氧合时段而非来源于间歇低氧时段,这一过程受到IH/ROX频率的影响.随着IH/ROX频率的不断增加,颈动脉体炎症状态、内皮素水平和窦神经长期易化先是逐渐增加,而后再逐渐下降.15 min的持续低氧未造成明确的炎性损伤,而HIF-1和VEGF是IH/ROX适应性通道成员.
目的 建立不同間歇低氧/再氧閤(IH/ROX)模式傢兔頸動脈體在體模型,探討不同頻率IH/ROX暴露後傢兔頸動脈體的炎癥狀態、內皮素水平和頸動脈體竇神經傳入活性. 方法 49隻成年雄性大耳白傢兔(2.5～3.0 kg)分為7組,每組7隻,分離右側頸總動脈和右竇神經,竇神經去包膜顯露髓鞘,遊離化學感受性神經細束記錄竇神經傳入活性.結扎近心耑,遠心耑內插入導管,經程控蠕動泵交替灌註以髮泡法預平衡的低氧灌註液和(或)正常氧灌註液,在右側頸總動脈內模擬睡眠呼吸暫停模式IH/ROX暴露條件或持續低氧條件.按灌註頻率分組為:間歇正常氧組(21%0:,15 s;21%02,1 min 45 s)、10次/h組(21%02,5 min 45 s)、30次/h組(21%02,1 min 45 s)、50次/h組(21%02,57 s)、60次/h組(21%02,45 s)、90次/h組(21%02,25 s),均反複灌註60次;持續低氧組:間歇正常灌註1 h 45 min,隨後給予5%O2持續15 min.靜置30 min,採集竇神經傳入活性頻率(Charge F),遊離收集右側頸動脈體,酶聯免疫吸附法(ELISA法)測定頸動脈體裂解液中白細胞介素-6(IL-6)、內皮素-1、低氧誘導因子-1(HIF-1)和血管內皮生長因子(VEGF)濃度併標準化.整體比較時採用單因素方差分析,配對比較用Tamhane T2法. 結果 隨著間歇正常氧頻率增加,IL-6、內皮素-1和Charge F整體均數呈現齣先升後降趨勢(F=25 601.39,2390.48,6945.84,均P＜0.05),50/hr組IL-6、內皮素-1和Charge F水平均高于其餘各組.且Charge F與IL-6和內皮素-1相關(r=0.736,0.757,均P＜0.05);而組間IL-6、內皮素-1和Charge F水平差異不明顯.隨著間歇低氧頻率增加,HIF-1水平逐漸增加(F=5241.10,P＜0.01),持續低氧組HIF-1水平最高.VEGF水平呈現齣先升後降再升趨勢(F=5931.30,P＜0.05),持續低氧組VEGF水平增加最明顯. 結論 IH/ROX暴露後頸動脈體竇神經傳入活性明顯增彊併與頸動脈體炎癥和血管收縮密切相關,頸動脈體的炎癥來源于再氧閤時段而非來源于間歇低氧時段,這一過程受到IH/ROX頻率的影響.隨著IH/ROX頻率的不斷增加,頸動脈體炎癥狀態、內皮素水平和竇神經長期易化先是逐漸增加,而後再逐漸下降.15 min的持續低氧未造成明確的炎性損傷,而HIF-1和VEGF是IH/ROX適應性通道成員.
목적 건립불동간헐저양/재양합(IH/ROX)모식가토경동맥체재체모형,탐토불동빈솔IH/ROX폭로후가토경동맥체적염증상태、내피소수평화경동맥체두신경전입활성. 방법 49지성년웅성대이백가토(2.5～3.0 kg)분위7조,매조7지,분리우측경총동맥화우두신경,두신경거포막현로수초,유리화학감수성신경세속기록두신경전입활성.결찰근심단,원심단내삽입도관,경정공연동빙교체관주이발포법예평형적저양관주액화(혹)정상양관주액,재우측경총동맥내모의수면호흡잠정모식IH/ROX폭로조건혹지속저양조건.안관주빈솔분조위:간헐정상양조(21%0:,15 s;21%02,1 min 45 s)、10차/h조(21%02,5 min 45 s)、30차/h조(21%02,1 min 45 s)、50차/h조(21%02,57 s)、60차/h조(21%02,45 s)、90차/h조(21%02,25 s),균반복관주60차;지속저양조:간헐정상관주1 h 45 min,수후급여5%O2지속15 min.정치30 min,채집두신경전입활성빈솔(Charge F),유리수집우측경동맥체,매련면역흡부법(ELISA법)측정경동맥체렬해액중백세포개소-6(IL-6)、내피소-1、저양유도인자-1(HIF-1)화혈관내피생장인자(VEGF)농도병표준화.정체비교시채용단인소방차분석,배대비교용Tamhane T2법. 결과 수착간헐정상양빈솔증가,IL-6、내피소-1화Charge F정체균수정현출선승후강추세(F=25 601.39,2390.48,6945.84,균P＜0.05),50/hr조IL-6、내피소-1화Charge F수평균고우기여각조.차Charge F여IL-6화내피소-1상관(r=0.736,0.757,균P＜0.05);이조간IL-6、내피소-1화Charge F수평차이불명현.수착간헐저양빈솔증가,HIF-1수평축점증가(F=5241.10,P＜0.01),지속저양조HIF-1수평최고.VEGF수평정현출선승후강재승추세(F=5931.30,P＜0.05),지속저양조VEGF수평증가최명현. 결론 IH/ROX폭로후경동맥체두신경전입활성명현증강병여경동맥체염증화혈관수축밀절상관,경동맥체적염증래원우재양합시단이비래원우간헐저양시단,저일과정수도IH/ROX빈솔적영향.수착IH/ROX빈솔적불단증가,경동맥체염증상태、내피소수평화두신경장기역화선시축점증가,이후재축점하강.15 min적지속저양미조성명학적염성손상,이HIF-1화VEGF시IH/ROX괄응성통도성원.
Objective To explore the inflammatory reactions,endothelin level and carotid sinus nerve(CSN)afferent activity of carotid body(CB)after intermittent hypoxia/reoxygenation(IH/ROX)exposure of various frequencies in rabbits.Methods Forty-nine male adult New Zealand white rabbits (2.5～3.0 kg)were separated into 7 groups(n=7 each).After anesthetization,the fight carotid artery and CSN were cleared of surrounding tissues without touching the right CB and the left carotid region.The CSN was unenveloped to pareally expose the myelin sheath.and electrodes were placed to the"single"chemoreceptor bundle of the CSN.with CSN afferent activity carefully monitored and recorded.Then the right common carotid artery was exposed,cannulated to distal part and its proximal part was ligated.Preparations were challenged by changing the PO2 of the gas mixture equilibrating the perfusate.Alternatively perfusion (2 mL/min) of equilibrated perfusate bubbled with normoxia or hypoxia gas mixtures formed IH/ROX cycles in right carotid common artery,simulating the pattern of hypoxic episodes seen in obstructive sleep apnea,or with continuously perfusing hypoxia perfusate to form continuous hypoxia (CH)modes.Groups were defined with different frequencies,and groups were: intermittent normnxia group (IN group) (21% O2,15 s;21% O2,1 min 45 s),10/hr group (5% O2,15 s ;21% O2,5 rain 45 s),30/hrgroup (5%O2,15 s;21%O2,1 min45 s),50/hr group (5%O2,15 s;21%O2,57 s),60/hr group (5%O2 ,15 s;21%O2,45 s) and 90/hr group (5%O2,15 s;21%O2,25 s).All the above groups were exposed to 60 treatment cycles;continuous hypoxia group (CH group),IN for 1 h 45min and then 5% O2 for 15 min.After exposure and 30 min of static placing,CSN afferent frequencies (Charge F) were recorded from chemoreceptor bundles,and the right CB was cleared of surrounding tissues and harvested.Interleukin-6 (IL-6),endothelin-1 (ET-1),hypoxla-indacible factor-1 (HIF-I),and vascular endothelial growth factor (VEGF) concentrations of the CB lysate were measured with enzyme linked immuno sorbent assay (ELISA)kits and standardized.Data were analyzed with SPSS 12.0 software package ;and after one way analysis of variance (ANOVA) for whole difference,Tamhane' s T2 was used for post hoc analysis.Results IL-6,ET-1 and Charge F increased but then decreased with increasing IH frequencies ( F = 25 601.39,2390.48,6945.84,all P values ＜ 0.01 ).IL-6,ET-1 and Charge F levels in 50/hr group were the highest among groups.Charge F levels correlated significantly with IL-6 or ET-1 ( with IL-6 : r = 0.736,P ＜ 0.01 ;with ET-1 : r = 0.757,P ＜ 0.01,respectively).IL-6,ET-1 and Charge F levels between IN group and CH group were not statistically different (all P values > 0.05 ).HIF-1 levels elevated gradually (F = 5241.10,P ＜0.01 ) with increasing exposure frequencies,and the CH group had the highest value (all P values ＜0.01 ).VEGF level in CH group was the highest in all groups ( all P values ＜0.01 ).Conclusions After IH/ROX exposure,afferent activity of CB CSN increases,which significantly correlates with inflammation and vasomotor mechanism of CB.CB inflammation comes not from IH phases but from ROX phases.Increased CB CSN activity results in elevated SNA tension,which plays a key role in the pathogenesis of systemic hypertension.This procedure influenced by IH/BOX frequencies.CH for 15 min causes no definitely damages.However,HIF-1 and VEGF can be considered as members of adaptive pathway during IH/ROX exposure.
