老龄犬肺部感染启动左心衰竭心肌能量代谢障碍的机制研究
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摘要
目的 研究老龄犬肺部感染启动左心功能不全的心肌能量代谢障碍机制,同时探寻左室功能预警状态。
方法
1.健康老龄犬左心室功能正常值参考范围的确立 健康老龄犬28只,年齿争均≥7岁,测定LVSPP、+dp/dt_(max)、t-dp/dt_(max)、LVEDP、-dp/dt_(max)。建立健康老龄犬(≥7岁)左心室功能的该5项指标95%正常值参考范围。
2。经皮穿刺右心室快速起搏老龄犬心功能不全模型的建立及心功能失代偿点的探寻。采用经皮穿刺颈静脉的方法植入VOO型起搏器,以240bpm的固定频率起搏,建立老龄犬左心室功能不全模型,探寻左心功能失代偿点。
3.铜绿假单胞菌致老龄犬肺部感染模型的建立 应用锐孔喷射装置,将铜绿假单胞菌制成藻酸盐包被体菌悬液,浓度为9×10~8cfu/ml,取10ml缓慢注入气管,使菌液均匀分布于两肺。72小时后,将犬处死,分离出肺组织,HE染色,光镜下观察,证实肺炎模型的建立。
4.老龄犬肺部感染启动左心功能不全心肌能量代谢障碍机制研究将老龄犬随机分为三组,起搏7天组、5天组、和3天组;对照组仅植入起搏器不予以起搏。于起搏的第7、5、3天停止起搏。起搏组和对照组都予以相同剂量的铜绿假单胞菌感染。于起搏前、停止起搏后、感染后3天测量左心功能五项指标,检测主动脉根部和冠状静脉窦内的血糖、游离脂肪酸、乳酸、氧分压、二氧化碳分压;获取左心室组织并行电镜检查。起搏后未出现左心衰,感染后也未出现。左心衰的最小+dp/dt_(max)和-dp/dt_(max)值的左心功能状态即为预警状态,此时+dp/dt_(max)和-dp/dt_(max)均数的95%可信区间即为左心室收缩功能和舒张功能预警区间。
ObjectivesTo study the mechanism of myocardial energy metabolic dysfunction in left heart insufficiency initiated by lung infection in elderly canines and to explore the warning state of LV function. Methods1. Set up of normal reference for LV function in elderly canines. 28 elderly canines, > 7 yrs of age, were catheterized to test LV Systolic Pressure Peak(LVSPP), the peak rate of pressure rise (+dp/dtmax), time to +dp/dt_(max)(t-dp/dt_(max)) ,LV End-Diastolic Pressure(LVEDP),the peak rate of pressure fall(-dp/dt_(max)),by which 95%confidence interval was to set up. 2. Cardiac insufficiency model produced by using percutaneous rapid right ventricular pacing and initially explore the turning point between compensated and decompensated heart failure .Seldinger technique was employed to puncture the jugular vein and VOO type of animal pacemaker were implanted with a pacing rate of 240bpm.3. Lung infection model produced by pseudomonas aeruginosa. A specially designed acute-hole jet device was employed to make the pseudomonas aeruginosa coated with alga acid in suspension with pseudomonas aeruginosa concentration of 9 x 10~8cfu/ml and then 10ml suspension was dropped through the airway cannulation to the lung.72 hours later, the lung was harvested for histological study(HE stain) to confirm the successful infection.4. Study of Mechanisms of Myocardial Energy Metabolic Disorder Responsible for LV dysfunction initiated by Lung Infection in Elderly
Canines.Elderly canines were randomized to three groups ,of,pacing5d and pacing3d and then were continuously paced at 240bpm with VOO pacemaker for 7 days,5days and 3days, respectively. Control dogs were aslo implanted pacemaker without pacing.The pacemaker was turned off at the 7th ,5th and 3rd day and the same amount of pseudomonas aeruginosa were given to have the canine lung infected.LV function were tested before pacing, at pacer off and 3rd day after infection.Blood sample were obtained at Aorta and CS for difference analysis ,including blood glucose,FFA,lactate,PO2,PCO2.Lung were obtained for histological study to confirm the infection and also heart were harvested for electron microscopy study of left ventricle.The warning state of LV function was defined as the state of minimum +dp/dtmax and -dp/dttmax that with no LV failure after both pacing and lung infection.The 95% confidence interval(CI) of +dp/dtmax and -dp/dtmax was the intended warning interval for LV function. Results1. 95% confidence interval(95%CI) of parameters for LV function : LVSPP = 119-171 mmHg, +dp/dtmax = 2932 - 4354 mmHg/s, t-dp/dW =33-49 ms, LVEDP = -5-7mmHg, -dp/dtmax = 2202 - 3426 mmHg/s.2. As pacing continues,LV contractility and rexation gradually impaired. At 7th day,test were performed to all canines and only one was confirmed to have developed heart failure.Till nineth day after onset of pacing,there were all together 4 HF canines .3. Lung infection model created by pseudomonas aeruginosa . Three days later ,the lungs were harvested for histological study and the results showed alveolus edema and bleeding.Neutrophils were found assembled at around the alga-acid coated pseudomonas aeruginosa and bronchus-alveolus abscess formed. 4. Influence of pacing and lung infection on myocardial energy metabolism 4.1 Influence of rapid pacing on LV energy metabolism. No significiant
changes of myocardial energy metabolism were found.4.2 Influence of lung infection on myocardial energy metabolism: (l)group of pacing7d: the myocardial glucose consumption was markedly increased and at the same time the CS lactate level increased.However, no significant changes of tFFA consumption was observed.The O2 consumption was markedly decreased.Myocardial release of CO2 was not markedly decreased. (2) group of pacing5d:The myocardial glucose consumption was markedly increased.Meanwhile, the CS lactate level increased.However, no significant changes of tFFA consumption was observed.The O2 consumption was markedly decreased.Myocardial release of CO2 was slightly increased. (3) group of pacing3d: the myocardial glucose consumption was markedly increased and the the CS lactate level increased.However, no significant changes of tFFA consumption was observed.The O2 consumption was markedly decreased.Myocardial release of CO2 was not markedly decreased.4.3 LV mitochondria] injury by lung infection By electron microscopy study, LV mitochondrial injury or destroy was found.Mitochondrial profile changed and the ratio of length to width was decreased.Meanwhile, the inner mitochondrial membrane was injuried or destroyed with the ridge missing partially or totally.4.4 Warning state of LV function: +dp/dW=3500-3SOOmmHg/sj-dp/dtmax =2400-2900mmHg/s.Conclusions1. Elderly canine lung infection caused by pseudomonas aeruginosa impaired LV function and the onset of left heart failure is up to the LV function prior to lung infection.LV function below warning state predicts heart failure and that beyond warning state predicts no failure.2. There is no significant changes of myocardial metabolism of left ventricle by rapid right ventricle pacing for 7days, 5days and 3days respectively.3. Glycolysis system may not be injuried by lung infection.
方法
1.健康老龄犬左心室功能正常值参考范围的确立 健康老龄犬28只,年齿争均≥7岁,测定LVSPP、+dp/dt_(max)、t-dp/dt_(max)、LVEDP、-dp/dt_(max)。建立健康老龄犬(≥7岁)左心室功能的该5项指标95%正常值参考范围。
2。经皮穿刺右心室快速起搏老龄犬心功能不全模型的建立及心功能失代偿点的探寻。采用经皮穿刺颈静脉的方法植入VOO型起搏器,以240bpm的固定频率起搏,建立老龄犬左心室功能不全模型,探寻左心功能失代偿点。
3.铜绿假单胞菌致老龄犬肺部感染模型的建立 应用锐孔喷射装置,将铜绿假单胞菌制成藻酸盐包被体菌悬液,浓度为9×10~8cfu/ml,取10ml缓慢注入气管,使菌液均匀分布于两肺。72小时后,将犬处死,分离出肺组织,HE染色,光镜下观察,证实肺炎模型的建立。
4.老龄犬肺部感染启动左心功能不全心肌能量代谢障碍机制研究将老龄犬随机分为三组,起搏7天组、5天组、和3天组;对照组仅植入起搏器不予以起搏。于起搏的第7、5、3天停止起搏。起搏组和对照组都予以相同剂量的铜绿假单胞菌感染。于起搏前、停止起搏后、感染后3天测量左心功能五项指标,检测主动脉根部和冠状静脉窦内的血糖、游离脂肪酸、乳酸、氧分压、二氧化碳分压;获取左心室组织并行电镜检查。起搏后未出现左心衰,感染后也未出现。左心衰的最小+dp/dt_(max)和-dp/dt_(max)值的左心功能状态即为预警状态,此时+dp/dt_(max)和-dp/dt_(max)均数的95%可信区间即为左心室收缩功能和舒张功能预警区间。
ObjectivesTo study the mechanism of myocardial energy metabolic dysfunction in left heart insufficiency initiated by lung infection in elderly canines and to explore the warning state of LV function. Methods1. Set up of normal reference for LV function in elderly canines. 28 elderly canines, > 7 yrs of age, were catheterized to test LV Systolic Pressure Peak(LVSPP), the peak rate of pressure rise (+dp/dtmax), time to +dp/dt_(max)(t-dp/dt_(max)) ,LV End-Diastolic Pressure(LVEDP),the peak rate of pressure fall(-dp/dt_(max)),by which 95%confidence interval was to set up. 2. Cardiac insufficiency model produced by using percutaneous rapid right ventricular pacing and initially explore the turning point between compensated and decompensated heart failure .Seldinger technique was employed to puncture the jugular vein and VOO type of animal pacemaker were implanted with a pacing rate of 240bpm.3. Lung infection model produced by pseudomonas aeruginosa. A specially designed acute-hole jet device was employed to make the pseudomonas aeruginosa coated with alga acid in suspension with pseudomonas aeruginosa concentration of 9 x 10~8cfu/ml and then 10ml suspension was dropped through the airway cannulation to the lung.72 hours later, the lung was harvested for histological study(HE stain) to confirm the successful infection.4. Study of Mechanisms of Myocardial Energy Metabolic Disorder Responsible for LV dysfunction initiated by Lung Infection in Elderly
Canines.Elderly canines were randomized to three groups ,of,pacing5d and pacing3d and then were continuously paced at 240bpm with VOO pacemaker for 7 days,5days and 3days, respectively. Control dogs were aslo implanted pacemaker without pacing.The pacemaker was turned off at the 7th ,5th and 3rd day and the same amount of pseudomonas aeruginosa were given to have the canine lung infected.LV function were tested before pacing, at pacer off and 3rd day after infection.Blood sample were obtained at Aorta and CS for difference analysis ,including blood glucose,FFA,lactate,PO2,PCO2.Lung were obtained for histological study to confirm the infection and also heart were harvested for electron microscopy study of left ventricle.The warning state of LV function was defined as the state of minimum +dp/dtmax and -dp/dttmax that with no LV failure after both pacing and lung infection.The 95% confidence interval(CI) of +dp/dtmax and -dp/dtmax was the intended warning interval for LV function. Results1. 95% confidence interval(95%CI) of parameters for LV function : LVSPP = 119-171 mmHg, +dp/dtmax = 2932 - 4354 mmHg/s, t-dp/dW =33-49 ms, LVEDP = -5-7mmHg, -dp/dtmax = 2202 - 3426 mmHg/s.2. As pacing continues,LV contractility and rexation gradually impaired. At 7th day,test were performed to all canines and only one was confirmed to have developed heart failure.Till nineth day after onset of pacing,there were all together 4 HF canines .3. Lung infection model created by pseudomonas aeruginosa . Three days later ,the lungs were harvested for histological study and the results showed alveolus edema and bleeding.Neutrophils were found assembled at around the alga-acid coated pseudomonas aeruginosa and bronchus-alveolus abscess formed. 4. Influence of pacing and lung infection on myocardial energy metabolism 4.1 Influence of rapid pacing on LV energy metabolism. No significiant
changes of myocardial energy metabolism were found.4.2 Influence of lung infection on myocardial energy metabolism: (l)group of pacing7d: the myocardial glucose consumption was markedly increased and at the same time the CS lactate level increased.However, no significant changes of tFFA consumption was observed.The O2 consumption was markedly decreased.Myocardial release of CO2 was not markedly decreased. (2) group of pacing5d:The myocardial glucose consumption was markedly increased.Meanwhile, the CS lactate level increased.However, no significant changes of tFFA consumption was observed.The O2 consumption was markedly decreased.Myocardial release of CO2 was slightly increased. (3) group of pacing3d: the myocardial glucose consumption was markedly increased and the the CS lactate level increased.However, no significant changes of tFFA consumption was observed.The O2 consumption was markedly decreased.Myocardial release of CO2 was not markedly decreased.4.3 LV mitochondria] injury by lung infection By electron microscopy study, LV mitochondrial injury or destroy was found.Mitochondrial profile changed and the ratio of length to width was decreased.Meanwhile, the inner mitochondrial membrane was injuried or destroyed with the ridge missing partially or totally.4.4 Warning state of LV function: +dp/dW=3500-3SOOmmHg/sj-dp/dtmax =2400-2900mmHg/s.Conclusions1. Elderly canine lung infection caused by pseudomonas aeruginosa impaired LV function and the onset of left heart failure is up to the LV function prior to lung infection.LV function below warning state predicts heart failure and that beyond warning state predicts no failure.2. There is no significant changes of myocardial metabolism of left ventricle by rapid right ventricle pacing for 7days, 5days and 3days respectively.3. Glycolysis system may not be injuried by lung infection.
引文
1 朱妙章,臧益民。心功能及其调节,心脏杂志,1996,8(增刊)。
2 朱妙章,臧益民。心脏结构与功能,见:侯应龙,杜日映主编,现代心力衰竭诊断治疗学。北京:人民军艺出版社,1997,3-18。
3 朱妙章,臧益民。心血管生理学进展,见:张宁仔,杜日映主编,心血管病学,北京:人民军医出版社,1999,21-41。
4 朱妙章,臧益民。心功能述评,见:沈文锦,徐成斌主编,现代心功能学,北京:人民军艺出版社,2002,1-17。
5 Katz A M. Physiology of the heart. 3rd ed. Philadelphia: Lippincott Wolliams and Wilkins, 2001.
6 Boron W F. Boulpaep E L, Medical physiology. Philadelphia: WB Saunder CO, 2003, 508-533.
7 Schiller N B, Foster E. Analysis of Left ventricular function. Heart, 1996, 75 (6 suppl 2) : 17-26
8 Yammaoto K, Redfield M M, Nishimura R A. Analysis of left ventricular diastolic function. Heart, 1996, 75 (6 suppl 2) : 27-35.
9 蒋知俭主编。医学统计学,北京:人民卫生出版社,1997,146-153。
2 朱妙章,臧益民。心脏结构与功能,见:侯应龙,杜日映主编,现代心力衰竭诊断治疗学。北京:人民军艺出版社,1997,3-18。
3 朱妙章,臧益民。心血管生理学进展,见:张宁仔,杜日映主编,心血管病学,北京:人民军医出版社,1999,21-41。
4 朱妙章,臧益民。心功能述评,见:沈文锦,徐成斌主编,现代心功能学,北京:人民军艺出版社,2002,1-17。
5 Katz A M. Physiology of the heart. 3rd ed. Philadelphia: Lippincott Wolliams and Wilkins, 2001.
6 Boron W F. Boulpaep E L, Medical physiology. Philadelphia: WB Saunder CO, 2003, 508-533.
7 Schiller N B, Foster E. Analysis of Left ventricular function. Heart, 1996, 75 (6 suppl 2) : 17-26
8 Yammaoto K, Redfield M M, Nishimura R A. Analysis of left ventricular diastolic function. Heart, 1996, 75 (6 suppl 2) : 27-35.
9 蒋知俭主编。医学统计学,北京:人民卫生出版社,1997,146-153。