磁共振磷谱(31P-MRS)探测不同年龄正常人骨骼肌能量代谢的特点

目的分析不同年龄组骨骼肌能量代谢特点。方法对10例成年人和6例青少年受试者进行31P MRS分析,对磷酸单酯(PME)、无机磷(Pi)、磷酸二酯(PDE)、磷酸肌酸(CP)、γ-ATP、α-ATP和β-ATP的峰下面积进行半绝对定量分析,同时间接计算二磷酸腺苷(ADP)和线粒体内氧化磷酸化潜能(PP)以及细胞内pH值和镁离子的浓度。比较2组受试者能量代谢相关化合物的含量。结果正常成年人(青少年)每千克骨骼肌内CP和总ATP含量分别为24.76(25.52)mmol和18.38(21.36)mmol。与成人相比,青少年ATP含量较高,PDE含量较低。pH值、镁合ATP及总镁离子含量青少年组均明显高于成人组。而Pi、CP、ADP、PP、自由镁离子和游离ATP的含量2组间无显著性差异。结论31P-MRS可无创探测细胞内能量代谢特点。     

3T动态磁共振磷谱对正常人骨骼肌线粒体功能的在体研究

目的：运用3T高场强磁共振动态磷谱技术（^31P-MRS）在体评价骨骼肌线粒体能量代谢情况。方法：对20名正常人受试者骨骼肌进行动态31P-MRS采集,后期利用Matlab软件对无机磷（Pi）、磷酸肌酸（PCr）、三磷酸腺苷（ATP）等化合物的峰下面积进行定量分析,分别计算在静止期,运动末期及数个恢复期骨骼肌内高能磷酸化合物的含量,同时计算二磷酸腺苷（ADP）和细胞内PH值,评价磁共振动态磷谱技术对研究骨骼肌线粒体功能的价值。结果：肌肉运动时PCr含量明显降低,Pi、Pi/PCr和ADP升高,恢复期各含磷化合物含量逐渐恢复至静息水平。结论：3T高场强动态磷谱技术可以无创性定量评价骨骼肌线粒体功能,为肌肉的功能影像学提供客观证据,为以后客观研究肌肉相关疾病提供了理想的方法。     

3 T磁共振动态磷谱对糖耐量异常患者骨骼肌线粒体功能的在体研究

目的用3 T磁共振动态磷谱技术(31P-MRS)在体无创性评价糖耐量异常(IGT)患者骨骼肌线粒体的功能。资料与方法对16例IGT患者和10名年龄、性别、体重指数(BMI)匹配的正常自愿者骨骼肌进行动态31P-MRS分析,对磷酸肌酸(PCr)、无机磷(Pi)、三磷酸腺苷(α-,β-,和γ-ATP)的半绝对定量分析,同时计算ADP、Pi/PCr、细胞内pH值及恢复期PCr、ADP起始恢复速率。分析静息、运动及恢复期两组受试者骨骼肌能量代谢特点以及线粒体功能状况。结果 IGT组PCr、β-ATP含量各期均低于对照组;ADP均高于对照组;恢复期,IGT组PCr、ADP的初始恢复速度明显低于对照组。Pi、Pi/PCr、pH值两组变化趋势相同,组间无差异。结论 IGT患者的骨骼肌基础能量代谢率降低,骨骼肌线粒体氧化磷酸化功能受损。     

骨骼肌代谢的31P-MRS研究及临床应用进展

磁共振磷谱(31P-MRS)是对不同组织能量代谢的一种无创性的研究方法.综述骨骼肌31P-MRS的基本技术和在骨骼肌代谢、肌肉疾病诊断中的应用,旨在为临床应用31P-MRS技术提供进一步研究的线索.     

骨骼肌代谢的^31P-MRS研究及临床应用进展

磁共振磷谱（^31P-MRS）是对不同组织能量代谢的一种无创性的研究方法。综述骨骼肌31P-MRS的基本技术和在骨骼肌代谢、肌肉疾病诊断中的应用，旨在为临床应用^31P-MRS技术提供进一步研究的线索。     

股四头肌31p-MRS对脂质沉积性肌病的诊断及疗效研究

目的 分析脂质沉积性肌病(lipid storage myopathy,LSM)患者静息时、亚极限运动后及治疗前后股四头肌31磷-磁共振波谱成像(31P-MRS)表现,并探讨31P-MRS对LSM的诊断及疗效价值.资料与方法 对经肌肉活检证实为LSM的9例患者行静息时、亚极限运动后即刻、5 min、10 min和15 min时31P-MRS成像.所有患者经强的松及左卡尼汀治疗后2～4个月(平均2.2个月)后再次行静息状态及亚极限运动后动态31P-MRS成像.对31P-MRS数据进行后处理,获得静息时磷酸肌酸(PCr)、无机磷(Pi)、Pi与三磷酸腺苷之比(Pi/ATP)、Pi/PCr、PCr/ATP、pH、二磷酸腺苷(ADP)、磷酸化能力(PP)和线粒体ATP生成率与线粒体最大产能量之比(Q/Vmax);运动后PCr生成率的速度常数( KPCr)、PCr最初生成率(ViPCr)和线粒体最大产能量(Vmax)等衡量线粒体功能的参数.并将9名年龄匹配的、未经专业体育训练的志愿者作为对照组与病变组静息时、亚极限运动后各项数据相对比.采用配对t检验比较分析病变组与对照组之间、病变组治疗前后的差别,所有数据用SPSS 13.0进行统计分析.结果 (1)治疗前病变组与对照组对比,将出现静息状态代谢物PCr、PCr/ATP、ADP静息状态指标1/PP及运动后指标ViPCr、KPCr、Vmax减小,经统计学分析差异有统计学意义.其他指标差异无统计学意义.(2)病变组治疗前后比较将出现静息状态代谢物ADP及运动后指标Vmax、Vi Pcr、KPcr减小,提示ADP及运动后参数更敏感.静息状态代谢物PCr、PCr/ATP及Pi、Pi/ATP无明显异常.结论 31P-MRS通过运动前后多种参数判断肌肉能量代谢变化、线粒体功能及氧化PP,对LSM的诊断及疗效评估具有重要价值.     

静息状态健康成人腓肠肌3.0T31P-MRS分析

目的 应用3.0T 31P-MRS对不同年龄组左腓肠肌磷代谢物定量分析,评估其磷代谢物特点,并为腓肠肌31P-MRS检查参数优化提供依据.方法 32例健康志愿者,在静息状态下进行31P-MRS单体素扫描,分别显示7个代谢产物波峰,同时计算pH值、PME/β-ATP、PCr/PME、β-ATP/Pi、PME/Pi、PDE/β-ATP相对定量分析.结果 健康成人静息状态下显示7个代谢物.PME、PCr、Pi、总ATP、PCr/PME、PME/Pi青年组和与老年组有统计学差异.中老年组PME、PME/β-ATP、β-ATP/Pi、PME/Pi、PDE/β-ATP男性与女性有统计学差异.结论 3.0T 31P-MRS可无创量化健康成人不同年龄、各组不同性别静息状态腓肠肌磷代谢产物.     

MRI及31P-MRS在脂质沉积性肌病中的诊断

目的:应用磁共振成像(MRI)及磷频谱(31P-MRS)评价脂质沉积性肌病(LSM)的影像表现,探讨其临床应用价值.方法:对经病理证实的6例LSM和17例健康对照者进行MRI及31P-MRS检查.结果:6例LSM患者大腿后组肌群和内侧肌群T1 WI及T2 WI上均表现为多发小斑点状高信号,T2 WI抑脂后信号减低;LSM组PCr(磷酸肌酸)、PCr/ATP(三磷酸腺苷)和磷酸化能力(PP)较对照组明显降低(P＜0.05),二磷酸腺苷(ADP)、Pi(无机磷)、Pi/ATP、Pi/PCr较对照组明显增高(P＜0.05),PH与对照组无明显差别(P=0.6395).结论:MRI联合31P-MRS检查有利于LSM的诊断、鉴别诊断.     

3.0T31P-MRS对骨与软组织肿瘤的诊断价值

目的 探讨超高场31P-MRS对骨与软组织肿瘤的成像特点.方法 对病理证实的骨与软组织肿瘤41例用磷表面线圈进行31P-MRS分析,测量波谱中各代谢产物的峰下面积,分别以三磷酸腺苷β峰(β-ATP)、三磷酸核苷(NTP)、磷酸肌酸(Pcr)为参照计算各代谢产物的相对比值,根据无机磷(Pi)相对于Pcr化学位移的变化计算细胞内pH值,进行相对定量分析.根据峰下面积计算各代谢产物与β-ATP、三磷酸核苷(NTP=ATP+Pi+Pcr)、Pcr的相对值PME/β-ATP、PDE/β-ATP、β-ATP/Pi、PME/NTP、PDE/NTP、Pcr/Pi及Pcr/PME.并运用SPSS11.5 for Windows软件包进行统计学处理,采用多个独立样本的非参数检验.结果 良、恶性肿瘤组的Pcr/PME、PME/NTP较对照组均有显著性差异(P<0.05).良、恶性肿瘤组PME/β-ATP、PME/NTP的差异有显著性意义(P<0.05).与正常组比较,良、恶性肿瘤组的PME和PDE及Pi峰升高,Pcr峰降低.结论 31P-MRS测得的Pcr/PME、PME/NTP与骨、软组织肿瘤相关,PME/β-ATP、PME/NTP在骨与软组织肿瘤的诊断和鉴别诊断中发挥重要的作用.     

健康成人肝脏~(31)P-MR波谱研究

目的:探讨健康成人肝脏31P-MR波谱及代谢生化信息特点.方法:分析20例健康志愿者31P-MR波谱检查肝脏代谢化合物信息及细胞内pH值,并将本组研究对象按年龄分为3组,分别为青年组(20～34岁)、中年组(35～49岁)和老年组(50～65岁),统计分析各年龄组间肝脏代谢物水平是否有差异.结果:20例研究对象肝脏31P-MRS均能显示磷酸单脂(PME) 、无机磷(Pi) 、磷酸双脂(PDE) 、磷酸肌酸(PCr)、γ-ATP、α-ATP和β-ATP共7种代谢产物峰(从左到右),其波峰化学位移分别为0.7～1.9、0.44～-0.75、-1.45～-2.65、-4.81～-6.13、-7.3～-8.46、-12.7～-14.05和-21.45～-22.77 ppm,其峰下积分面积分别为0.8±0.57、0.97±0.68、2.51±1.59、0.61±0.5、2.11±0.99和1.14±0.85,计算肝组织PH值为7.35±0.04.经方差分析,各年龄组间PME、Pi、PDE、γ-ATP、α- ATP和β-ATP代谢物峰下面积和细胞内PH值均无统计学差异(P》0.05),肝脏代谢化合物含量、能量状况及细胞内PH值不随年龄改变而变化.结论:肝脏31P-MRS能无创、直接检测肝代谢过程的生化信息及能量状况,对了解肝脏代谢情况具有重要临床价值.     

Muscle high-energy metabolites and metabolic capacity in patients with heart failure

OKITA, K., K. YONEZAWA, H. NISHIJIMA, A. HANADA, T. NAGAI, T. MURAKAMI, and A. KITABATAKE. Muscle high-energy metabolites and metabolic capacity in patients with heart failure. Med Sci. Sports. Exerc., Vol. 33, No. 3, 2001, pp. 442-448. Background: Various abnormalities in skeletal muscle have been demonstrated by biopsy in patients with chronic heart failure (CHF). In mammalian muscles, high-energy metabolite composition at rest (HEMC) provides data on important metabolic characteristics; however, the significance of HEMC has not been clarified in patients with CHF. Therefore, we investigated HEMC in normal subjects and patients with CHF and examined its relation to muscle metabolic capacity and exercise tolerance. Methods: High-energy metabolites (phosphocreatine (PCr), inorganic phosphate (Pi), and ATP) in resting calf muscle were measured by 31P-magnetic resonance spectroscopy (31P-MRS), and ratios of Pi to PCr, Pi to ATP, and PCr to ATP were calculated in 34 patients with CHF and 13 age- and size-matched normal subjects. Muscle metabolism was evaluated during local exercise of unilateral plantar flexion by 31P-MRS. Metabolic capacity was estimated by the rate of PCr breakdown in relation to the workload. Systemic exercise capacity was evaluated by a bicycle ergometer. Results: The ratio of PCr to ATP was significantly increased in patients with CHF compared with controls (3.06 +/- 0.43 vs 2.72 +/- 0.36, P < 0.05) and was significantly correlated with metabolic capacity (r = -0.37, P < 0.01) and with peak oxygen uptake (r = -0.45, P < 0.01). There was a significant correlation between metabolic capacity and peak oxygen uptake (r = 0.53, P < 0.001). Conclusion: HEMC was altered in patients with CHF, and this change was related to metabolic capacity and exercise capacity. These findings provide new insight into the mechanism of impaired muscle metabolism in CHF.     

Exertional heatstroke and muscle metabolism: an in vivo 31P-MRS study.

An impairment of muscle energy metabolism has been suggested as a predisposing factor for, as well as a consequence of exertional heatstroke (EHS). Thirteen young men were investigated 6 months after a well-documented EHS using 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS). The relative concentrations of ATP, phosphocreatine (PCr), inorganic phosphate (Pi), phosphomonoesters (PME), and the intracellular pH (pHi) were determined at rest, during a graded standardized exercise protocol (360 active plantar flexions) and during recovery. Also the leg tissue blood flow was determined by venous occlusion plethysmography during the MRS procedure. Sixteen age-matched healthy male volunteers served as control group. In resting muscle, there were no significant differences between the groups as regards pHi, Pi/PCr, and ATP/PCr+Pi+PME ratios. During steady state exercise conditions, effective power outputs were similar for both groups at each level of exercise: 20, 35, and 50% of maximal voluntary contraction (MVC) of the calf muscle. No significant differences were shown between the two groups in Pi/PCr, pHi, or changes of leg blood flow at each level of exercise. At 50% MVC, Pi/PCr was 0.48 +/- 0.08 vs 0.47 +/- 0.05 (P = 0.96), pHi was 6.94 +/- 0.03 vs 6.99 +/- 0.02, respectively (P = 0.13). Finally, the rate of PCr resynthesis during recovery was not significantly different between the two groups: t1/2 PCr = 0.58 +/- 0.07 vs 0.50 +/- 0.05 min, respectively (P = 0.35). Therefore, no evidence of an impairment of muscle energy metabolism was shown in the EHS group during a standardized submaximal exercise using 31P-MRS performed 6 months after an EHS.     

Assessment of functional severity on in vivo hepatic 31P-MRS in diffuse hepatic disease: comparative studies with 99mTc-GSA

The purpose of this study was to compare the assessment of functional severity on in-vivo hepatic 31P-MRS in diffuse hepatic disease with functional severity assessed with 99mTc galactosyl serum albumin (99mTc-GSA). 31P-MRS was performed in 10 healthy control subjects and 16 patients with diffuse hepatic disease. Data were expressed as peak area ratios: PME/beta-ATP, PDE/beta-ATP, PME/PDE, Pi/beta-ATP, and PME/Pi. The functional severity of hepatic damage was evaluated visually and quantitatively (HH15, LHL15) by 99mTc-GSA in the group of patients with diffuse hepatic disease. Visual evaluation was classified into four grades based on anterior images of cardiac blood-pool and liver. We studied the correlation of spectral metabolic ratios and functional severity by 99mTc-GSA. We found statistically significant differences (ANOVA) among the classifications of Grade I, Grade II, and Grade III with both PME/beta-ATP and PME/PDE. A statistically significant direct correlation was found between HH15 and both PME/beta-ATP and PME/PDE. A significant inverse correlation was also seen between LHL15 and both PME/beta-ATP and PME/PDE. The studies comparing 31P-MRS with functional severity assessed by 99mTc-GSA showed that PME/beta-ATP and PME/PDE were useful for the assessment of functional severity in patients with diffuse hepatic disease.     

Phosphorus 31-magnetic resonance spectroscopic studies of animal liver after extracorporeal shock wave lithotripsy]

The technique of magnetic resonance spectroscopy has been developed, and the study of high-energy phosphate metabolites in the liver using phosphorus 31 magnetic resonance spectroscopy (31P-MRS) has been reported in humans and animals, but few studies have used 31P-MRS for the evaluation of extracorporeal shock wave lithotripsy (ESWL) of the liver. In this study, 31P-MRS was used to evaluate the metabolic changes in hamster liver after ESWL and histological correlation was performed. Syrian golden hamsters were anesthetized and shock waves were irradiated to the left side of the liver. Hamsters were irradiated by LITHOSTAR-PLUS (SIEMENS) at a voltage of 19 KV. 31P-MRS was studied by JNM-GSX model 270 (6.34 Tesla). Typical peaks of 31P-spectra of hamster liver showed a tendency for PDE/beta-ATP, alpha-ATP/beta-ATP and gamma-ATP/beta-ATP to decrease among the irradiated group compared with the control group. However, there were no significant differences in PME/Pi, beta-ATP/Pi or (alpha-ATP-beta-ATP)/beta-ATP between the control group and irradiated group. With regard to intracellular pH and PDE/beta-ATP, a decreasing tendency was noted in the irradiated groups (p less than 0.05). There was no difference in the signal intensity of T1WI and T2WI on 1H-MRI, between these two groups. Pathologically, the irradiated group showed minor hemorrhage and edema in the liver, and subcapsular hematoma. The results obtained from 31P-MRS clearly showed the metabolic changes and were correlated well with the histological findings, but MRI was not capable of providing close visualization of post-ESWL liver damage.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of thermal damage after hyperthermia on murine experimental tumor by 31P-NMR spectroscopy--correlation between ATP and growth curve]

The possibility of using 31P-NMR spectroscopy (31P-MRS) to estimate the effect of hyperthermic treatment on mouse FM3A tumor was investigated. 1 x 10(6) cells, suspended in saline, were subcutaneously inoculated to the right thigh of C3H mice. For hyperthermic treatment, the tumor-bearing leg was heated by immersing it in a water bath at 44 degrees C for 10, 20 or 30 min. The signal intensities of ATP and Pi of the tumor were measured utilizing the 31P-MRS technique to calculate the ATP/Pi ratio. Immediately after heating, the ATP/Pi ratio decreased markedly. Eighteen hours after hyperthermic treatment, the ratio recovered but was still smaller than the control value, then became almost constant by 24 hours after heating. The ATP/Pi ratio at 24 hours after heating decreased with increased length of heating and was inversely related to tumor regrowth after hyperthermic treatment. We concluded that non-invasive monitoring with 31P-MRS might provide a good indication of the effect of hyperthermic treatment.     

Isokinetic eccentric exercise as a model to induce and reproduce pathophysiological alterations related to delayed onset muscle soreness

Physiological alterations following unaccustomed eccentric exercise in an isokinetic dynamometer of the right m. quadriceps until exhaustion were studied, in order to create a model in which the physiological responses to physiotherapy could be measured. In experiment I (exp. I), seven selected parameters were measured bilaterally in 7 healthy subjects at day 0 as a control value. Then after a standardized bout of eccentric exercise the same parameters were measured daily for the following 7 d (test values). The measured parameters were: the ratio of phosphocreatine to inorganic phosphate (PCr/P_i), the ratio of inorganic phosphate to adenosintriphosphate (Pi/ATP), the ratio of phosphocreatine to adenosintriphosphate (PCr/ATP) (all three ratios measured with ³¹P-nuclear magnetic resonance spectroscopy), dynamic muscle strength, plasma creatine kinase (CK), degree of pain and “muscle” blood flow rate (¹³³Xenon washout technique). This was repeated in experiment II (exp. II) 6–12 months later in order to study reproducbility. In experiment III (exp. III), the normal fluctuations over 8 d of the seven parameters were measured, without intervention with eccentric exercise in 6 other subjects. All subjects experienced pain, reaching a maximum 48 h after eccentric exercise in both exp. I and II. A systematic effect over time for CK (increasing 278% resp. 308%), muscle strength (decreasing more than 10%), PCr/Pi (decreasing 31% resp. 43%) and Pi/ATP (increasing 55% resp. 99%) was found in both exp. I and II (P<0.05), but not in exp. III. No significant difference was observed between exp. I and II for CK, blood-flow rate, concentric muscle strength, PCr/Pi, Pi/ATP and PCr/ATP. It is concluded that pathophysiological alterations in m. quadriceps following eccentric exercise can be induced and can be reproduced after an interval of 6 months. Thus, this model can be used to study the effects of physiotherapy.