Glycogen content and activities of key glycolytic enzymes in muscle biopsies from control subjects and patients with chronic alcoholic skeletal myopathy

The capacity for glycolysis in muscle biopsies obtained from long-term heavy alcohol drinking patients has been compared with tissue from control subjects by assay in vitro of the total activities of glycogen phosphorylase, phosphofructokinase and fructose 1,6-bisphosphatase, key regulatory enzymes in the anaerobic glycolytic pathway. Biopsies from 13 of 22 patients had type II fibre atrophy, and the activities of all three enzymes were reduced in these biopsies, when expressed in terms of DNA content, the most striking reduction being in phosphofructokinase activity. The amount of glycogen in the tissue correlated closely with these enzyme activities and was slightly lower in the most atrophic tissue, when expressed in terms of DNA content. The activities of acid and neutral alpha-glucosidases were similar in biopsies from control subjects and patients with various severities of alcohol myopathy. The reduced activities are consistent with a reduced proportion of type II fibre muscle mass in these patients, and suggest that there may be a reduced capacity for glycolysis with resultant reduced lactate production. Whether the changes in enzyme activities are primary to the selective atrophy remains to be established.     

Glucocorticosteroid status in chronic alcoholics with and without skeletal muscle myopathy

1. Chronic alcoholism is associated with a selective atrophy of type II skeletal muscle fibres. We studied the glucocorticoid status of chronic alcoholics with and without myopathy to determine if hypercortisolism is responsible for the myopathy. 2. Twenty-four hour urinary cortisol excretion and diurnal serum cortisol measurements were not significantly different in chronic alcoholics, with and without atrophy of type II skeletal muscle fibres. 3. Diurnal serum cortisol variation was normal for both groups of alcoholics studied. None of the patients with myopathy had raised serum cortisol levels. 4. We conclude that chronic alcoholic myopathy is not due to alcohol-related pseudo-Cushing's syndrome.     

Assessment in vitro and in vivo of muscle degradation in chronic skeletal muscle myopathy of alcoholism

1. Muscle protein breakdown in vivo has been studied by measurements of urinary 3-methyl-histidine/creatinine ratios. No differences were found between control subjects and chronic alcoholics either with or without proximal muscle wasting or cirrhosis. 2. Calculation of muscle turnover rates, with the correction of Afting et al. (1981, Biochemical Journal, 200, 449-452) for non-skeletal muscle contributions of 3-methylhistidine and creatinine, showed lower values for alcoholics compared with controls. 3. Tissue activities of a neutral protease, assayed by a novel, rapid and sensitive fluorimetric method, were similar in patients and controls. The activity did not vary with severity of atrophy or the presence of cirrhosis. 4. No evidence was therefore obtained to suggest that alcoholic myopathy is due to increased muscle breakdown.     

Decreased activity of carnosinase in serum of patients with chronic liver disorders

We measured the activity of carnosinase, a prominent hepatic peptidase, in sera from 69 patients with liver disorders. Mean values (and SDs) for those with liver cirrhosis (17 cases) and hepatoma (seven cases) were 0.51 (0.28) and 0.68 (0.21) mumol/mL per hour, respectively--clearly less than for normal adults: 4.19 (0.95) mumol/mL per hour. Samples from 17 cases of chronic hepatitis also showed moderately decreased activity, 1.41 (0.97) mumol/mL per hour. In contrast, 14 cases of acute hepatitis generally showed values falling within the normal limits: 3.41 (1.97) mumol/mL per hour. Our results for carnosinase correlated with those for cholinesterase (r = 0.70) and with the concentration of albumin in serum (r = 0.59), but not with the activity of either creatine kinase, aspartate aminotransferase, or alanine aminotransferase in serum. Carnosinase values differed more among groups of disorders than did the values for cholinesterase or albumin. Measurement of serum carnosinase activity may be of clinical value in assessing the severity of chronic liver-cell damage, but not in differentiating liver disease from nutritional, muscle, or endocrine disorders.     

Low-dose ethanol consumption allows strength recovery in chronic alcoholic myopathy

Chronic skeletal myopathy may affect one third of chronic alcohol misusers. It is generally accepted that abstinence allows partial recovery, and that continued high-dose ethanol consumption progressively deteriorates muscle function. However, the effect of low-dose ethanol consumption in alcoholic myopathy has not been studied. We studied 58 chronic alcoholic male patients with biopsy-proven chronic alcoholic myopathy over 5 years. We evaluated ethanol intake, biochemical and nutritional parameters, and assessed muscle strength. Eighteen patients who remained abstinent showed marked improvement in muscle strength. As expected, the 19 patients who persisted in high-dose ethanol consumption further diminished in their muscle strength. In the 11 patients who maintained low-dose (相似文献   

Impaired nutritive skeletal muscle blood flow in patients with chronic renal failure

1. The possibility that abnormalities of skeletal muscle may limit the exercise tolerance of patients with chronic renal failure was investigated in patients undergoing regular haemodialysis. 2. Blood flow to the calf, a vascular bed consisting predominantly of skeletal muscle, was measured in six patients before and after exercise and compared with values obtained from 12 control subjects. 3. The patients were limited on exertion and had an abnormal response of calf blood flow to bicycle exercise. Resting calf blood flow was similar in patients and control subjects, but the mean increase in calf blood flow in response to submaximal exercise was 0.55 (SEM 0.12) ml min-1 100 ml-1 in the patients and 1.43 (SEM 0.17) ml min-1 100 ml-1 in the control subjects. The increase after symptom-limited maximal exercise was 1.50 (SEM 0.80) ml min-1 100 ml-1 in the patients and 4.20 (SEM 0.40) ml min-1 100 ml-1 in the control subjects. 4. Skeletal muscle biopsies from eight haemodialysis patients were studied by histochemistry and electron microscopy. 5. Oxidative enzyme activity was increased and there were large subsarcolemmal aggregates of structurally normal mitochondria. Necrotic capillaries were observed as empty basement membrane tubes containing fragments of degenerating endothelium. 6. The changes were compatible with a response to a chronic reduction in skeletal muscle blood flow.     

Serum enzymes in disease of skeletal muscle

Creatine kinase is the serum enzyme that shows the greatest frequency of abnormality in skeletal muscle disease. Changes in this enzyme in sex-linked dystrophy (Duchenne's and Becker's) patients and carriers; in patients with other dystrophies; and in inflammatory, toxic, endocrine, and traumatic myopathy are reviewed. The changing role of serum enzyme measurements as a consequence of newer methods of genetic diagnosis is also considered.     

缺血性脑卒中患者血清肌肽酶的动态变化及其意义

目的 观察急性缺血性脑卒中患者血清肌肽酶(HSC)的变化,并探讨HSC水平同脑梗死灶大小、神经学状态和功能间的关系.方法 采用荧光法分光光度法检测急性脑缺血患者发病后48 h内、第5 d、第7 d和第14 d HSC活性.所有患者于相应时间点进行神经学状态评估(NIHSS),出院时评估神经学功能(Barthel index).结果 (1)HSC于发病第5 d即开始降低,第7 d显著低于对照组(P＝0.034),第14 d升高到正常水平(P＝0.105);虽然发病48 h内、5 d及14 d HSC同对照组无显著差异,但第5 d、第7 d和第14 d HSC活性均显著低于第3 d(P＝0.023,0.002和0.013),第7 d也低于第5 d(P＝0.000),第14 d同第5 d和第7 d相比无差异(P＞0.05).(2)发病后的第7 d和第14 d,大梗死灶组、小梗死灶组和对照组HSC差别显著(P＝0.032和0.033).经两两比较,大梗死灶组于第7天HSC显著低于对照组(P＜0.05),第14d HSC也分别低于较小梗死灶组和对照组(均为P＜0.05),而小梗死灶组和对照组均无差异(P＞0.05).(3)未发现HSC同NIHSS和Barthel Index有显著意义的相关性.结论 急性缺血性脑卒中患者发病后HSC活性显著降低,并且梗死灶大的患者降低的幅度大.HSC能否作为缺血性脑损伤严重程度的判断指标值得进一步关注.     

运动训练对慢性心力衰竭患者运动耐量的影响

目的　探讨运动训练对慢性心力衰竭患者运动耐量的影响。方法　 70例患者随机分为 2组 ,A组 (n =3 4)运动培训 3周 ,B组 (n =3 6)限制活动 3周 ,然后比较 2组 6min内步行的距离、左室射血分数(超声心动图测定 )、血白介素 6(双抗体夹心法 )及去甲肾上腺素浓度 (荧光法测定 )的变化。结果　运动训练组患者试验后 6min步行距离 ( 3 85± 3 0 .12 )m ,血IL 6( 0 .86± 0 .2 5 ) pmol/L ,NE( 2 .0 5± 0 .48)nmol/L ,LVEF( 43± 5 .2 3 ) % ,上述各指标与对照组相比 ,差异均有显著性意义 (P <0 .0 5 ) ,而且运动试验组试验前、后各指标的差异也有显著性意义 (P <0 .0 5 ) ,但对照组试验前、后差异无显著性意义 (P >0 .0 5 )。结论　运动训练能改善慢性心力衰竭患者的运动能力及心功能 ,对慢性心力衰竭患者的康复治疗是有益的。     

Lower muscle endurance in patients with alcoholic liver disease

Patients with alcoholic liver disease often complain of restricted physical capacity, which could be due to decreased muscle endurance. The aim of this study was to assess the muscular endurance in patients with alcoholic liver disease. In a cross sectional study, 24 patients with alcoholic liver disease and 22 controls were evaluated using isometric dynamometry. Endurance was determined during contractions for 3 min elicited by intermittent external electrical stimuli to the femoral quadriceps muscle. Second, endurance was evaluated during voluntary contractions by performance of a maximal isometric knee extension maintained for 1.5 min. Although no difference between patients and controls was found for voluntary contractions, the patients did have lower involuntary muscular endurance. Muscular endurance was not related to lean body mass. Maximal voluntary isometric muscle strength and total work of knee extensors were almost halved in the patients and lower also after correction for differences in lean body mass. In addition to low-muscle strength, patients with alcoholic liver disease have lower involuntary isometric muscular endurance unrelated to lean body mass.     

Glucose tolerance in relation to skeletal muscle enzyme activities in cancer patients.

Glucose metabolism and skeletal muscle enzyme activities were studied in nineteen cancer patients and twelve matched controls. The fasting insulin values were normal but the fasting glucose values and the sum of glucose were increased and the sum of insulin was decreased during intravenous glucose tolerance test in the cancer patients. The elimination rate of glucose (k-value) during glucose challenge was, however, not significantly different in cancer patients as compared with that of appropriate controls. The activities of enzymes representative for glycogen turnover, glycolysis, citric acid cycle and respiratory chain were significantly lower in the muscle tissue of cancer patients, while the activity of 3-hydroxyacyl-CoA dehydrogenase, an enzyme in the beta-oxidation of fatty acids, was unchanged and the activity of glucose-6-phosphate dehydrogenase was significantly higher. Rate limiting enzyme activities in muscle tissue, phosphofructokinase and cytochrome c oxidase correlated signficantly with plasma insulin and glucose during glucose challenge. The results point at the possibility of covariating debilitation of pancreatic beta-cells and skeletal muscle enzymes caused by the malignant tumour.     

Serum paraoxonase and arylesterase activities for the evaluation of patients with chronic hepatitis

The sensitivity of standard biochemical tests for liver function is low and insufficient for a reliable determination of the presence or absence of liver disease. The aim of the present study was to investigate serum paraoxonase and arylesterase activities and lipid hydroperoxide (LOOH) levels, and to find out that whether the measurement of serum paraoxonase and arylesterase activities would be useful as an index of liver function status in chronic hepatitis (CH). Fourty-four patients with CH (24 CHB and 20 CHC) and 38 controls were enrolled. Serum paraoxonase and arylesterase activities were detected spectrophotometrically. LOOH levels were measured by the FOX-2 assay. Serum paraoxonase and arylesterase activities were significantly lower in patients with CH than controls (p < 0.001 for both), while LOOH levels were significantly higher (p < 0.001). Paraoxonase and arylesterase activities were inversely correlated with LOOH levels (r = -0.394, p < 0.05; r =-0.362, p < 0.05, respectively). Fibrosis scores of CH patients were significantly correlated with paraoxonase and arylesterase activities and LOOH levels (r =-0.276, p < 0.05; r = -0.583, p < 0.001 and r = 0.562, p < 0.001, respectively). Our results indicated that decrease in the activities paraoxonase and arylesterase may play a role in the pathogenesis of CH. In addition, serum paraoxonase and arylesterase activities measurement may add a significant contribution to the liver function tests.     

Phenytoin loading in chronic alcoholic patients

Controversy exists concerning the appropriate loading dose of phenytoin in chronic alcoholic patients. Chronic alcoholics are frequently assumed to have low albumin levels secondary to malnutrition and liver disease. Phenytoin is bound to albumin, and therefore the usual loading dose of phenytoin might result in a higher percentage of unbound drug and increased toxicity in these patients. Thirty-six chronic alcoholic patients were given a 15-mg/kg loading dose of phenytoin by constant intravenous infusion. After the infusion, patients were evaluated for clinical signs of phenytoin toxicity. At 1 hour after infusion, blood was sent for determination of total phenytoin, free phenytoin, and albumin levels. Fifteen patients were hypoalbuminemic (mean, 3.4 g/dL); 21 patients had albumin levels within the normal range (mean, 4.3 g/dL). In the hypoalbuminemic group, the mean free phenytoin level was 1.1 micrograms/mL, and the mean total phenytoin level was 13.6 micrograms/mL. In patients with normal albumin levels, the mean free phenytoin level was 1.3 micrograms/mL, and the mean total phenytoin level was 15.7 micrograms/mL. There were no statistically significant differences in total phenytoin or free phenytoin levels between either groups. No patient had a postinfusion phenytoin level (either free or total) within the toxic range. Although our sample size was small, our results suggest that a 15-mg/kg loading dose of phenytoin does not produce toxic levels in chronic alcoholics.     

Effects of chronic ethanol abuse on structure and enzyme activities of skeletal muscle in man.

Biopsies from vastus lateralis muscle of male patients suffering from chronic ethanol abuse were studied with regard to histochemical reactions of ATPase and NADH-diaphorase; enzymatic activities of triosephosphate dehydrogenase (TPD), lactate dehydrogenase (LD), and cytochrome c oxidase (cytox); content of ATP, creatine phosphate, and glycogen; and volume fractions of fat, mitochondria, and fibrillar and extrafibrillar space. The results were compared with those from controls without known abuse of ethanol. The relative numbers of fibers were the same in two groups, but the size of the fast-twitch-glycolytic (white) fibers was diminished in the alcoholic group. The activities of TPD and LD were diminished in skeletal muscle of the alcoholics. This is most probably caused by the reduced amount of fast-twitch-glycolytic tissue, as there was a good correlation between this amount and the activity of the two enzymes. The activity of cytox was slightly lower in muscle of the alcoholics than in that of the controls. The volume fraction of mitochondria was lower in the alcoholic group than in the control group. Volume fractions of fat and fibrillar and extrafibrillar space were equal in the two groups. No significant differences were found in the amount of glycogen and ATP in the muscle of the two groups. However, the content of creatine phosphate is higher in the alcoholic group than in the control group.     

自体回移肌卫星细胞对慢性骨筋膜间隔综合征致骨骼损伤后的修复作用

目的探讨自体回移成年兔肌卫星细胞对慢性骨筋膜间隔综合征所致的骨骼肌损伤后的修复作用。 方法24只新西兰大白兔随机分为模型移植组、模型对照组和移植对照组,每组8只。模型移植组和模型对照组建立慢性骨筋膜间隔综合征模型,模型移植组造模后移植肌卫星细胞;移植对照组不建模,仅移植肌卫星细胞。体外分离模型移植组和移植对照组比目鱼肌来源的肌卫星细胞,经体外一定程度扩增和鉴定,用DAPI标记后回移到原比目鱼肌,观察移植后肌卫星细胞在体内的自我增殖和分化情况。并采用HE染色观察移植前、后模型移植组受损肌肉的形态学变化。 结果回移相同数量的肌卫星细胞后第28天,模型移植组的肌卫星细胞数量显著增多,而移植对照组无明显变化。从病理切片看到,慢性压迫结束即刻,无论移植对照组或模型对照组,其压迫侧比目鱼肌的病理切片均显示较大面积的肌纤维坏死、间质纤维坏死、少量炎症细胞浸润;移植对照组的骨骼肌形态正常。肌卫星细胞自体移植后第28天,病理切片显示模型移植组的受损组织已明显修复,只见少量纤维化;模型对照组无明显改变,纤维化已稳定;移植对照组的骨骼肌形态正常。 结论慢性骨筋膜间隔综合征异常增高的压力解除后,肌卫星细胞体外一定程度扩增后自体回移,能提高受损骨骼肌的修复能力。