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1.
Spinal transection results in profound neural and functional changes of the heart. However, phenotypic alterations in cardiac myosin heavy chains (MyHC) as a result of spinal transection have not been explored. Hearts were removed from 180 day old rats who had their spinal cords transected between T6 and T9 (ST; n = 10) and intact controls (IN; n = 9). Myosin was isolated from the left and right ventricles and separated into its respective heavy chain components (designated as alpha and beta) by SDS-PAGE. The resulting gels were scanned with a laser scanning densitometer to obtain relative concentrations of these two heavy chains. The left ventricles of the ST rats had a significantly higher (p < 0.05) alpha to beta ratio (10.89) than the intact controls (4.20), while the right ventricle of the ST rats had a significantly lower (p < 0.05) alpha to beta ratio (7.49) relative to intact controls (13.62). The left and right ventricular weight to body weight ratios were not different in ST compared to IN. Additionally, there were significant within group differences (p < 0.05) between the alpha and beta MyHC ratios for the left and right ventricles. These data suggest that 1) spinal transection causes remodeling of the right and left ventricles and 2) the two ventricles do not remodel as a unit. 相似文献
2.
Schott P Singer SS Kögler H Neddermeier D Leineweber K Brodde OE Regitz-Zagrosek V Schmidt B Dihazi H Hasenfuss G 《Proteomics》2005,5(5):1372-1381
Treatment with monocrotaline causes pulmonary hypertension in rats. This results in severe pressure overload-induced hypertrophy of the right ventricles, whilst the normally loaded left ventricles do not hypertrophy. Both ventricles are affected by enhanced neuroendocrine stimulation in this model. We analyzed in this model load-induced and catecholamine-induced changes of right and left ventricular proteome by two-dimensional gel electrophoresis, tryptic in-gel digest, and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. All analyzed animals showed right ventricular hypertrophy without signs of heart failure. Changes of 27 proteins in the right and 21 proteins in the left ventricular myocardium were found. Given the hemodynamic features of this animal model, proteome changes restricted to the right ventricle are caused by pressure overload. We describe for the first time a potentially novel pathway (BRAP2/BRCA1) that is involved in myocardial hypertrophy. Furthermore, we demonstrate that increased afterload-induced hypertrophy leads to striking changes in the energy metabolism with down-regulation of pyruvate dehydrogenase (subunit beta E1), isocitrate dehydrogenase, succinyl coenzyme A ligase, NADH dehydrogenase, ubiquinol-cytochrome C reductase, and propionyl coenzyme A carboxylase. These changes go in parallel with alterations of the thin filament proteome (troponin T, tropomyosin), probably associated with Ca(2+) sensitization of the myofilaments. In contrast, neurohumoral stimulation of the left ventricle increases the abundance of proteins relevant for energy metabolism. This study represents the first in-depth analysis of global proteome alterations in a controlled animal model of pressure overload-induced myocardial hypertrophy. 相似文献
3.
A morphometric analysis was done on the lymph capillaries of both left and right ventricles from the rabbit heart. The measurements were made on the lymphatics identified in the subepicardium, myocardium and subendocardium of the ventricular walls. Quantitative evaluations were carried out on light and electron microscopic sections by a computerized image analysis system. The following parameters were selected and measured: (1) the diameter (of area-equivalent circle) of lymph capillaries, (2) the diameter of the uncoated micropinocytotic vesicles (located on the abluminal and adluminal side and in the cytoplasm of the endothelial cell) and the area occupied by the vesicles per unit area of cytoplasm. Differences in the size of the lymph capillaries were found in the three layers (subepicardium, myocardium and subendocardium) of the ventricular walls. The largest vessels were present in the subepicardium both in the left ventricle and in the right one. No significant variations were found in the lymphatics of corresponding regions on both ventricles. Little variations on the mean diameter of the uncoated micropinocytotic vesicles are present in the three regions of the endothelial wall. In the left ventricle only, the subendocardial vesicles are significantly larger than the subepicardial and the myocardial ones (p less than 0.05). The areal density occupied by vesicular system in the three layers of the ventricular wall showed significant differences in both ventricles (p less than 0.05). The vesicles present in the subepicardial vessels occupied the smallest areal density. No significant variations existed in the vesicular areal density between the two ventricles.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
Daneshrad Z Garcia-Riera MP Verdys M Rossi A 《Molecular and cellular biochemistry》2000,210(1-2):159-166
Chronic exposure of mammals to hypoxia induces a state of anorexia. We aimed to determine the role played by diet restriction in the alterations of myocardial energy metabolism occurring under chronic hypoxia in order to detect the specific effects of hypoxia per se.Adult female rats were exposed to normobaric hypoxia (Fi O2 = 0.10) for three weeks; pair-fed rats, kept under normoxic conditions, received the same amount of food as hypoxic rats. The oxidative capacity of myocardial ventricles and some skeletal muscles was evaluated using permeabilized fibers. Several metabolic enzyme activities were measured on extracts from myocardium and soleus.Diet restriction increased the activity of lactate dehydrogenase in both ventricles while it augmented phosphofructokinase and pyruvate kinase activities only in the left ventricle and depressed the respiratory rate in the right ventricle only.Hypoxia per se induced a rise in hexokinase activity in all studied oxidative muscles and a fall of hydroxy-acyl CoA-dehydrogenase activity in both myocardial ventricles. The respiratory rate and the citrate synthase activities were unaffected by hypoxia.We conclude that chronic hypoxia per se leads to specific alterations in myocardial metabolism that could favor the use of exogenous glucose at the expense of free fatty acids without any change in the oxidative capacity. 相似文献
5.
Ferrer T Gallego M Madrigal-Quiñónez R Torres-Jácome J Navarro-Polanco R Cásis O Sánchez-Chapula JA 《Life sciences》2006,79(9):883-889
Diabetes Mellitus (DM) can produce an increase in the cardiac action potential duration and QT interval that can be associated with sudden death. These cardiac effects are due to a region-specific decrease in repolarizing outward K(+) currents. Some authors have suggested that the proarrhythmic effects of diabetes can be due to diabetes-induced hypothyroidism. Thus, we have examined the effect of the thyroid hormone analog diiodothyropropionic acid (DITPA) on calcium-independent outward potassium currents in ventricular myocytes from diabetic rats. Sustained (I(ss)) and fast transient outward (I(tof)) K(+) currents were recorded using the whole-cell configuration of the patch-clamp technique. Myocytes were enzymatically isolated from the free wall of the right ventricle, and the epicardial and endocardial layers of the left ventricle of healthy, diabetic and DITPA-treated diabetic rats. Circulating thyroid hormones were measured by electrochemiluminescence. DITPA-treatment of diabetic rats restored I(tof) and I(ss) current densities in cardiac myocytes from the three regions studied, but did not alter current densities in myocytes of control rats. T(3) and T(4) levels were reduced by diabetes, and DITPA-treatment increased circulating T(3) levels. T(3)-treatment of diabetic rats also restored current densities to control values. However, direct incubation of diabetic myocytes with DITPA did not restore current densities. In summary, DITPA-treatment of diabetic rats restored the potassium current (I(tof) and I(ss)) densities in myocytes from all ventricular regions. 相似文献
6.
Lipid peroxidation and scavenging enzyme levels in the liver of streptozotocin-induced diabetic rats
Bukan N Sancak B Yavuz O Koca C Tutkun F Ozçelikay AT Altan N 《Indian journal of biochemistry & biophysics》2003,40(6):447-450
In this study, alterations in the liver antioxidant enzymes status and lipid peroxidation in short-term (8-weeks) and long-term (24-weeks) diabetic rats were examined. Glutathione peroxidase (GSH-Px) activity and malondialdehyde (MDA) levels were significantly increased, but superoxide dismutase (SOD) activity was significantly reduced in 8-weeks diabetic rats, compared to control. Catalase (CAT) activity, however, was found unchanged. In 24-weeks diabetic rats, while GSH-Px activity was unchanged, but SOD and CAT activities and MDA levels were significantly increased, compared to control. These results suggest that diabetes-induced alterations in tissue antioxidant system may reflect a generalized increase in tissue oxidative stress. It can be concluded that lipid peroxidation and antioxidant enzyme levels are elevated in diabetic condition. Hence, diabetes mellitus, if left untreated, may increase degenerative processes due to accumulation of oxidative free radicals. 相似文献
7.
Background
Cardiac diseases (e.g. coronary and valve) are associated with ventricular cellular remodeling. However, ventricular biopsies from left and right ventricles from patients with different pathologies are rare and thus little is known about disease-induced cellular remodeling in both sides of the heart and between different diseases. We hypothesized that the protein expression profiles between right and left ventricles of patients with aortic valve stenosis (AVS) and patients with coronary artery disease (CAD) are different and that the protein profile is different between the two diseases. Left and right ventricular biopsies were collected from patients with either CAD or AVS. The biopsies were processed for proteomic analysis using isobaric tandem mass tagging and analyzed by reverse phase nano-LC-MS/MS. Western blot for selected proteins showed strong correlation with proteomic analysis.Results
Proteomic analysis between ventricles of the same disease (intra-disease) and between ventricles of different diseases (inter-disease) identified more than 500 proteins detected in all relevant ventricular biopsies. Comparison between ventricles and disease state was focused on proteins with relatively high fold (±1.2 fold difference) and significant (P < 0.05) differences. Intra-disease protein expression differences between left and right ventricles were largely structural for AVS patients and largely signaling/metabolism for CAD. Proteins commonly associated with hypertrophy were also different in the AVS group but with lower fold difference. Inter-disease differences between left ventricles of AVS and CAD were detected in 9 proteins. However, inter-disease differences between the right ventricles of CAD and AVS patients were associated with differences in 73 proteins. The majority of proteins which had a significant difference in one ventricle compared to the other pathology also had a similar trend in the adjacent ventricle.Conclusions
This work demonstrates for the first time that left and right ventricles have a different proteome and that the difference is dependent on the type of disease. Inter-disease differential expression was more prominent for right ventricles. The finding that a protein change in one ventricle was often associated with a similar trend in the adjacent ventricle for a large number of proteins suggests cross-talk proteome remodeling between adjacent ventricles. 相似文献8.
As the Na+/Ca2+ exchanger plays an important role in the regulation of myocyte contractility, it has been suggested that alterations in this system might be involved in the development of insulin resistance and/or diabetes-induced myocardial alterations. Moreover, gene expression and function of the Na+/Ca2+ exchanger in states of combined hypertension and insulin resistance is of a special interest. Thus, we used hereditary hypertriglyceridemic (hHTg) rat (a model of genetically induced insulin resistance and hypertension) to study the effect of losartan, the blocker of type 1 angiotensin receptors, on the Na+/Ca2+ exchanger in the rat heart. We found that gene expression, but not activity of the Na+/Ca2+ exchanger was decreased in the left ventricle of hHTg rats when compared to their normotensive mates. No changes were observed in the right ventricle. In addition, losartan decreased mRNA levels of the Na+/Ca2+ exchanger in the left, but not in the right ventricle of normotensive rats. In hHTg rats, losartan had no effect on the gene expression of this transporter. Our results point to different modulatory pathways of Na+/Ca2+ exchanger in normotensive and hHTg rats. 相似文献
9.
M. L. Blagonravov M. V. Onufriev E. A. Demurov N. V. Gulyaeva V. A. Frolov 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2011,5(2):171-174
It is well known that chronic overload of the cardiac left ventricle is accompanied by an increase in the cardiomyocyte apoptosis
rate. However, direction and extent of changes in programmed cell death under an acute overload of the left ventricle still
requires detailed investigation (as its pathogenesis significantly differs from chronic overload). Caspase-3 activity has
been investigated in left ventricle myocardium of rabbits on days 1, 3, and 5 after modeling of left ventricle hemodynamic
overload caused by experimental stenosis of the ascending aorta. Control group included intact animals. It was found that
caspase-3 activity significantly increased in both ventricles on day 1; it increased more than twofold above control values
on day 3 and decreased up to nearly control values on day 5. Based on these data it was concluded that the acute hemodynamic
overload of the left ventricle may be a cause of increased apoptosis in the myocardial tissue of both cardiac ventricles during
first days of the pathological process. 相似文献
10.
In the present study the effect of thyroxine treatment on the development of cardiomegaly was compared in young (10-day-old) and adult (12-week-old) rats. L-thyroxine was administered subcutaneously in a dose of 1 mg per kg b.w. for 5 days. In young thyroxine-treated rats the heart weight increased by 79% in comparison with the control rats. The number of blood capillaries and muscle fibres per mm2 remained unchanged. The concentration of hydroxyproline was even lower than in control animals. The number of 3H-thymidine-labelled muscle cell nuclei was significantly higher both in the left and right ventricles of thyroxine treated rats. The density of capillaries and muscle fibres was significantly lower in adult rats than in the group of young animals. In adult thyroxine-treated animals the heart weight was higher by 36%, the number of capillaries and muscle fibres as well as the concentration of hydroxyproline was unchanged. Thyroxine induced significant increase in the number of DNA synthesizing nuclei of muscle cells in the left ventricle while the change in the right ventricular myocardium was not statistically significant. The present data indicate that a hyperplastic response of cardiac muscle cells to thyroxine occurs in both ventricles of young rats and also in the left ventricle of adult animals. 相似文献
11.
Inhomogeneity in the response to mechanical stimulation: cardiac muscle function and gene expression 总被引:2,自引:2,他引:0
Stones R Gilbert SH Benoist D White E 《Progress in biophysics and molecular biology》2008,97(2-3):268-281
Mechanical stimulation has important consequences for myocardial function. However, this stimulation and the response to it, is not uniform. The right ventricle is thinner walled and operates at lower pressure than the left ventricle. Within the ventricles, differences in the orientation of myocardial fibres exist. These differences produce inhomogeneity in the stress and strain between and across the ventricles. Possibly as a result of these variations in mechanical stimulation, there are well characterised inhomogeneities in gene expression and protein function within the ventricular myocardium, for example in the transient outward K+ current and its associated Kv channels. Perhaps not surprisingly, it is becoming apparent that gradients of expression and function exist for proteins that are intimately involved in the response to mechanical stimulation in the heart, for example in the left ventricle of the rat there is a transmural gradient in mRNA and current density of the mechanosensitive two-pore domain K+ channel TREK-1 (ENDO>EPI). In healthy hearts it is assumed that these gradients are important for normal function and therefore that their disruption in diseased myocardium is involved in the dysfunction that occurs. 相似文献
12.
A. Venturini R. Ascione H. Lin E. Polesel G. D. Angelini M.-S. Suleiman 《Molecular and cellular biochemistry》2009,330(1-2):63-70
Taurine, glutamine, glutamate, aspartate, and alanine are the most abundant intracellular free amino acids in human heart. The myocardial concentration of these amino acids changes during ischemia and reperfusion due to alterations in metabolic and ionic homeostasis. We hypothesized that dilated left ventricle secondary to mitral valve disease has different levels of amino acids compared to the right ventricle and that such differences determine the extent of amino acids' changes during ischemia and reperfusion. Myocardial concentration of amino acids was measured in biopsies collected from left and right ventricles before cardioplegic arrest (Custodiol HTK) and 10 min after reperfusion in patients undergoing mitral valve surgery. The dilated left ventricle had markedly higher (P < 0.05) concentrations (nmol/mg wet weight) of taurine (17.0 ± 1.5 vs. 10.9 ± 1.5), glutamine (20.5 ± 2.4 vs. 12.1 ± 1.2), and glutamate (18.3 ± 2.2 vs. 11.4 ± 1.5) when compared to right ventricle. There were no differences in the basal levels of alanine or aspartate. Upon reperfusion, a significant (P < 0.05) fall in taurine and glutamine was seen only in the left ventricle. These changes are likely to be due to transport (taurine) and/or metabolism (glutamine). There was a marked increase in the alanine to glutamate ratio in both ventricles indicative of ischemic stress which was confirmed by global release of lactate during reperfusion. This study shows that in contrast to the right ventricle, the dilated left ventricle had remodeled to accumulate amino acids which are used during ischemia and reperfusion. Whether these changes reflect differences in degree of cardioplegic protection between the two ventricles remain to be investigated. 相似文献
13.
目的对cTnTR141W扩张型心肌病转基因模型小鼠左、右心室进行对比分析,研究cTnTR141W转基因小鼠作为右心室心肌病的动物模型的可行性。方法利用7.0 T高场强磁共振成像(MRI)技术,定量分析了2、4、6和8月龄对照组及cTnTR141W转基因模型小鼠左、右心室的舒张末容积(EDV)、收缩末容积(ESV)和射血分数(EF)的变化情况,同时对6月龄对照组cTnTR141W转基因模型小鼠心肌组织进行组织学分析。结果转基因阴性对照小鼠相比,cTnTR141W转基因小鼠左、右心室的容积在2月龄时已有增大趋势,而射血分数有减小趋势。右心室射血分数减小出现最早也最显著(P<0.05)。随年龄增加,cTnTR141W转基因小鼠与转基因阴性对照小鼠相比,右心室的结构和功能的病理生理变化与左心室同时趋于严重。该小鼠左、右心室在4月龄后表现典型的扩张型心肌病表型。结论 cTnTR141W转基因模型小鼠左心室和右心室的扩张性心肌病表型同时出现,该小鼠可作为右室性心肌病等右心室功能下降相关疾病研究的动物模型。 相似文献
14.
Testis glutathione peroxidase and phospholipid hydroperoxide glutathione peroxidase activities in aminoguanidine-treated diabetic rats 总被引:3,自引:0,他引:3
Severe steroidogenic and spermatogenic alterations are reported in association with diabetic manifestations in humans and experimental animals. This study was planned to determine whether oxidative stress is involved in diabetes-induced alterations in the testes. Diabetes was induced in male rats by injection of 50 mg/kg of streptozotocin (STZ). Ten weeks after injection of STZ, levels of selenium and activities of selenium dependent-glutathione peroxidase (GPx) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) were measured in rat testis. Lipid and protein oxidations were evaluated as measurements of testis malondialdehyde (MDA) and protein carbonyl levels, respectively. Testis sulfydryl (SH) levels were also determined. The control levels of GPx and PHGPx activities were found to be 46.5 +/- 6.2 and 108.8 +/- 19.8 nmol GSH/mg protein/min, respectively. Diabetes caused an increase in testis GPx (65.0 +/- 21.1) and PHGPx (155.9 +/- 43.1) activities but did not affect the levels of selenium or SH. However, the testis MDA and protein carbonyl levels as markers of lipid and protein oxidation, respectively, did not increase in the diabetic group. Aminoguanidine (AG) treatment of diabetic rats returned the testis PHGPx activity (136.5 +/- 24.9) to the control level but did not change the value of GPx activity (69.2 +/- 17.4) compared with diabetic group. MDA and protein carbonyl levels in testis were not affected by AG treatment of diabetic rats, but interestingly AG caused SH levels to increase. The results indicate that reactive oxygen radicals were not involved in possible testicular complications of diabetes because diabetes-induced activations of GPx and PHGPx provided protection against oxidative stress, which was reported to be related to some diabetic complications. 相似文献
15.
Nouette-Gaulain K Biais M Savineau JP Marthan R Mazat JP Letellier T Sztark F 《Canadian journal of physiology and pharmacology》2011,89(1):58-66
Chronic hypoxia alters mitochondrial energy metabolism. In the heart, oxidative capacity of both ventricles is decreased after 3 weeks of chronic hypoxia. The aim of this study was to evaluate the reversal of these metabolic changes upon normoxia recovery. Rats were exposed to a hypobaric environment for 3 weeks and then subjected to a normoxic environment for 3 weeks (normoxia-recovery group) and compared with rats maintained in a normoxic environment (control group). Mitochondrial energy metabolism was differentially examined in both left and right ventricles. Oxidative capacity (oxygen consumption and ATP synthesis) was measured in saponin-skinned fibers. Activities of mitochondrial respiratory chain complexes and antioxidant enzymes were measured on ventricle homogenates. Morphometric analysis of mitochondria was performed on electron micrographs. In normoxia-recovery rats, oxidative capacities of right ventricles were decreased in the presence of glutamate or palmitoyl carnitine as substrates. In contrast, oxidation of palmitoyl carnitine was maintained in the left ventricle. Enzyme activities of complexes III and IV were significantly decreased in both ventricles. These functional alterations were associated with a decrease in numerical density and an increase in size of mitochondria. Finally, in the normoxia-recovery group, the antioxidant enzyme activities (catalase and glutathione peroxidase) increased. In conclusion, alterations of mitochondrial energy metabolism induced by chronic hypoxia are not totally reversible. Reactive oxygen species could be involved and should be investigated under such conditions, since they may represent a therapeutic target. 相似文献
16.
Schneider R Welt K Aust W Kluge R Löster H Fitzl G 《Histology and histopathology》2010,25(12):1581-1590
Cardiovascular autonomic neuropathy causes abnormalities in the diabetic heart with various clinical sequelae, including exercise intolerance, arrhythmias and painless myocardial infarction. Little is known about (ultra)structural alterations of the myocardial nervous network. On the assumption that this diabetes-specific neuropathy develops due to permanently increased oxidative stress by liberation of oxygen-free radicals, adjuvant application of antioxidative therapeutics appears promising in preventing or delaying long-term diabetic complications. We have investigated the effects of Ginkgo biloba extract (EGb 761), a radical scavenger, against diabetes-induced myocardial nervous damage in spontaneously diabetic BioBreeding/Ottawa Karlsburg (BB/OK) rats. Morphological and morphometric parameters were evaluated by electron microscopy. We used immunohistochemistry to investigate protein expression of protein gene product 9.5, S100 protein, and thyroxin hydroxylase as a neuronal marker. Alterations of cardiac sympathetic activity were measured using the in vivo 123I-metaiodobenzyl-guanidine imaging, and the immunofluorescent labeling of beta1-adrenergic receptors and adenylate cyclase. Our results revealed that A) Diabetes results in slight to moderate ultrastructural alterations (hydrops, disintegration of substructure) of autonomic nerve fibers and related Schwann cells in untreated BB diabetic rats; B) Cardiac sympathetic integrity and activity is impaired due to alterations in the presynaptic nerve terminals and the postsynaptic ?1-AR-AC coupling system; C) Pre-treatment of diabetic myocardium with EGb results in an improvement of most of these parameters compared to unprotected myocardium. In conclusion, EGb may act as a potent therapeutic adjuvant in diabetics with respect to cardiovascular autonomic neuropathy, which may contribute to the prevention of late complications in diabetes. 相似文献
17.
18.
M Wachtlová V Mares B Ostádal 《Virchows Archiv. B, Cell pathology including molecular pathology》1977,24(4):335-342
Intermittent high altitude (IHA) hypoxia (7000 m) increased the wet weight of the right ventricular myocardium of 30-day-old rats after two 4 h/day exposures. During the same period the number of DNA-synthesizing nuclei of both muscle and non-muscle cell types increased proportionally. After 4 such exposures to hypoxia the number of 3H-thymidine-labelled nuclei in both cell types increased further. In addition, the number of labelled nuclei increased significantly in the yet un-enlarged left ventricle. While there was no difference in the number of DNA-synthesizing cells between the right and left ventricles in control animals, a significant increase in the number of cells involved in DNA synthesis in the right ventricle was found in both groups of animals exposed to IHA hypoxia. These results show that DNA synthesis in myonuclei of the ventricular myocardium can be stimulated in 30-day-old rats, i.e. at the very end of the weaning period. 相似文献
19.
Kharin SN Kibler NA Shmakov DN 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2008,94(6):670-680
The pump function of the heart ventricles was studied in chest-open anaesthetized adult female chickens under sinus rhythm and ectopic excitation of different localization. The intraventricular pressure in the right and left heart ventricles was measured by insertion of catheters through the ventricular free walls. Maximum systolic pressure, end-diastolic pressure, contractility (dP/dtmax) and relaxation (dP/dtmin) of both heart ventricles, and duration of the asynchronous contraction time of the left ventricle were analyzed. It was revealed that reduction of the pump function of the left ventricle tends to be greater under right ventricular ectopic excitation compared with left ventricular one. In comparison with the sinus rhythm, the pump function of the right ventricle was preserved to a greater extent under stimulation of the left ventricular apex and was significantly impaired under right ventricular ectopic excitation. Relaxation of both heart ventricles was more susceptible to ventricular ectopic excitation than contractility, and was more vulnerable in the right ventricle than in the left one. The direction of changes of the pump function of the heart ventricles in chickens under ventricular ectopic excitation was similar to changes of the pump function of mammalian hearts. 相似文献
20.
在12只犬,结扎四支冠脉,造成犬心右室、左室大面积梗塞和心源性休克时,左室收缩压(LVSP)及最大正负压力阶差(±dp/dtmax.)分别下降54%、51%和47%,而右室收缩压(RVSP)及±dp/dtmax.仅降低9%、25%和27%。组Ⅰ(6只犬)快速扩容(低分子右旋糖酐30ml/kg,20min内静脉输入),结果右室反向搏动增强,双心室±dp/dtmax.进一步降低,右房压(RAP)及左室舒张末压(LVEDP)极度升高达2.9±0.2kPa和5.0±0.3kPa(P均<0.01),甚至诱发室颤。组Ⅱ缓慢静点多巴胺(10μg/kg·min)和硝酸甘油(1μg/kg·min)30min,有效提高了动脉压(AP),心输出量(CO),LVSP及左室±dp/dtmax.使休克逆转。结果表明,大面积左、右室梗塞伴休克时,右室残余心肌的代偿性收缩仍能造成RVSP与右室泵功能呈分离状态;此时快速扩容将进一步损害左、右室功能,而联合使用硝酸甘油和多巴胺能有效纠正休克同时不造成RAP和LVEDP的升高。 相似文献