Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie最新文献_第7页

Inhibition of mitochondrial carnitine acylcarnitine translocase by hypoglycaemia-inducing substances. 低血糖诱导物质对线粒体肉碱酰基肉碱转位酶的抑制作用。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

M Beneking, M Oellerich, L Binder, G F Choitz, R Haeckel

{"title":"Inhibition of mitochondrial carnitine acylcarnitine translocase by hypoglycaemia-inducing substances.","authors":"M Beneking, M Oellerich, L Binder, G F Choitz, R Haeckel","doi":"","DOIUrl":"","url":null,"abstract":"The rate of mitochondrial carnitine-carnitine exchange mediated by carnitine acylcarnitine translocase was measured in the presence of the two hypoglycaemia-inducing drugs, 2-(3-methyl-cinnamyl-hydrazono)-propionate and 2-(3-phenylpropoxyimino)-butyric acid (BM 13.677). Both substances caused a concentration-dependent decrease in the rate of carnitine uptake in guinea pig liver mitochondria. Apparent initial influx rates were decreased by 75% and 80% at a concentration of 2 mmol/l 2-(3-methyl-cinnamyl-hydrazono)-propionate and 2-(3-phenylpropoxyimino)-butyric acid, respectively. Intraperitoneal injections of 212 mumol 2-(3-phenylpropoxyimino)-butyric acid or 21 mumol 2-(3-methyl-cinnamyl-hydrazono)-propionate per kg body weight caused a noticeable decrease in blood glucose concentration. A significant fall of the blood ketone body concentration was achieved with 2-(3-methyl-cinnamyl-hydrazono)-propionate or 2-(3-phenylpropoxyimino)-butyric acid, at dosages of 21 and 255 mumol/l, respectively. Furthermore there was a dose-dependent increase in the plasma free fatty acid concentration in the presence of 2-(3-methyl-cinnamyl-hydrazono)-propionate. This increase, however, was much less pronounced with 2-(3-phenylpropoxyimino)-butyric acid. Metabolic effects of 2-(3-methyl-cinnamyl-hydrazono)-propionate are consistent with an inhibition of long-chain fatty acid transport, whereas an additional mechanism of action has to be assumed for 2-(3-phenylpropoxyimino)-butyric acid.","PeriodicalId":15649,"journal":{"name":"Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie","volume":"28 5","pages":"323-7"},"PeriodicalIF":0.0,"publicationDate":"1990-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13271487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Role of the liver in carnitine metabolism: the mechanism of development of carnitine-deficient status in guinea-pigs. 肝脏在肉毒碱代谢中的作用:豚鼠肉毒碱缺乏状态的发展机制。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

I Alkonyi, J Cseko, A Sandor

引用次数: 0

Effects of acylcarnitine transferase blockade on metabolism and function in the normally and underperfused canine myocardium. 酰基肉碱转移酶阻断剂对正常和欠灌注犬心肌代谢和功能的影响。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

R Seitelberger, S Huber, S Schwarzacher, G Raberger

{"title":"Effects of acylcarnitine transferase blockade on metabolism and function in the normally and underperfused canine myocardium.","authors":"R Seitelberger, S Huber, S Schwarzacher, G Raberger","doi":"","DOIUrl":"","url":null,"abstract":"The acylcarnitine transferase blocking agent, sodium 2(5-(4-chlorophenyl)-pentyl)-oxirane-2-carboxylate (Clomoxir, INN), effectively inhibits free fatty acid oxidation, thereby decreasing myocardial oxygen consumption in the normally perfused myocardium without influencing cardiodynamic parameters. As a consequence, however, arterial free fatty acid levels increase significantly. In an acute dog model, we investigated the hypothesis that the sodium 2(5-(4-chlorophenyl)-pentyl)-oxirane-2-carboxylate-induced decrease in myocardial oxygen consumption may also improve the energetic situation in the underperfused myocardium. Regional myocardial function was assessed by means of subendocardially inserted ultrasonic crystals, and changes in metabolism were measured regionally by means of a catheter inserted into a local myocardial vein in the underperfused area. The flow in the circumflex coronary artery was reduced on average by 53.5% followed 30 min later by an infusion of sodium 2(5-(4-chlorophenyl)-pentyl)-oxirane-2-carboxylate (dosage: 20 mg/kg over 20 min). Arterial free fatty acid levels continuously increased, whereas arterial glucose levels decreased. In accordance with the situation in the normally perfused myocardium, free fatty acid uptake and oxygen uptake were also reduced in the underperfused area. However, sodium 2(5-(4-chlorophenyl)-pentyl)-oxirane-2-carboxylate induced a further, transient increase in end-diastolic segment length and a sustained decrease in systolic shortening in the underperfused area, indicating a further deterioration in regional myocardial function. Control experiments with infusion of 9 g/l sodium chloride showed no change in the degree of regional myocardial dysfunction throughout the observation period.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":15649,"journal":{"name":"Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie","volume":"28 5","pages":"341-6"},"PeriodicalIF":0.0,"publicationDate":"1990-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13528338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of seasonal biorhythms on urinary excretion of enzymes and other parameters. 季节性生物节律对尿中酶及其他参数的影响。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

H Grötsch, M Hropot, E Klaus, J Wesely

引用次数: 0

Effect of carnitine on foetal rat lung dipalmitoyl phosphatidylcholine content and lung morphology. Carnitine and lung surfactant, I. 肉碱对胎鼠肺双棕榈酰磷脂酰胆碱含量及肺形态的影响。肉毒碱和肺表面活性剂。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

A Lohninger, P Böck, C Dadak, A Feiks, E Kaiser

{"title":"Effect of carnitine on foetal rat lung dipalmitoyl phosphatidylcholine content and lung morphology. Carnitine and lung surfactant, I.","authors":"A Lohninger, P Böck, C Dadak, A Feiks, E Kaiser","doi":"","DOIUrl":"","url":null,"abstract":"Lungs of foetal rats between the 16th and 20th gestational day (total gestation lasting 22 days) were examined. There was a striking increase of both total phosphatidylcholine and dipalmitoyl phosphatidylcholine from day 19 to 20 of gestation. The carnitine content increased continuously from day 17 both in the foetal lungs and livers. In both organs, the increase in short-chain acylcarnitine was more pronounced than the increase in free carnitine. Compared with an untreated control group, treatment of the mother with L-carnitine (from day 16 to 18 of gestation, with 60, 80, and 100 mg/kg.d L-carnitine, respectively) resulted in significant increases in both total phospholipid (p less than 0.05 in all treated groups) and dipalmitoyl phosphatidylcholine (p less than 0.05, p less than 0.01, p less than 0.001, corresponding to maternal treatment with 60, 80, 100 mg/kg.d, respectively) on the 19th gestational day. The results are in accordance with morphological evaluations: with increasing carnitine-dosage, increasing numbers of lamellar bodies in type II cell progenitors were found. The enhanced dipalmitoyl phosphatidylcholine content is a consequence of enhanced phospholipid synthesis in remarkably undifferentiated type II cells largely lacking membrane structures and cell organelles capable of phospholipid synthesis. Thus, in general, carnitine treatment seems to stimulate foetal lung phospholipid synthesis, thereby enhancing the dipalmitoyl phosphatidylcholine content.","PeriodicalId":15649,"journal":{"name":"Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie","volume":"28 5","pages":"313-8"},"PeriodicalIF":0.0,"publicationDate":"1990-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13528334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Secondary carnitine deficiency. 继发性肉碱缺乏症。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

M Duran, N E Loof, D Ketting, L Dorland

{"title":"Secondary carnitine deficiency.","authors":"M Duran, N E Loof, D Ketting, L Dorland","doi":"","DOIUrl":"","url":null,"abstract":"For any given tissue the normal carnitine content is that which is necessary for an optimal rate of long-chain fatty acid oxidation. Tissues especially rich in carnitine are liver, muscle and heart. The endogenous rate of carnitine biosynthesis from lysine and methionine is not known to be influenced by fluctuations in the levels of the parent amino acids, as exemplified by hypermethioninaemic patients. Inadequate dietary supply of carnitine, leading to a deficiency, may occur in vegetarians and especially in subjects on total parenteral nutrition. Premature babies are especially at risk in this respect, and this has led to the addition of carnitine to solutions for intravenous alimentation. It has been suggested that carnitine plays an important role in the intramitochondrial regulations of coenzyme A homeostasis by expelling short-chain and medium-chain acyl groups from the mitochondrion in the form of acylcarnitines. These esters are preferentially excreted into the urine and thus result in a depletion of the body's carnitine stores. Important conditions in this respect are the inherited organic acidurias and disorders of fatty acid oxidation. Urinary acylcarnitines can be identified by indirect gas chromatographic or direct mass spectrometric methods. Patients on haemodialysis treatment will lose carnitine in the dialysis fluid, whereas excessive urinary losses of free and acetylated carnitine occur in the Fanconi syndrome. Secondary carnitine deficiency may be accompanied by a moderate degree of muscular dysfunction. Reassuringly, however, no signs of hepatic or cardiac involvement, as often seen in primary carnitine deficiency, have been observed.","PeriodicalId":15649,"journal":{"name":"Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie","volume":"28 5","pages":"359-63"},"PeriodicalIF":0.0,"publicationDate":"1990-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13352653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The role of carnitine in intracellular metabolism. 肉毒碱在细胞内代谢中的作用。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

J Bremer

{"title":"The role of carnitine in intracellular metabolism.","authors":"J Bremer","doi":"","DOIUrl":"","url":null,"abstract":"In animal cells long chain fatty acids are transferred into the mitochondria for oxidation as acylcarnitines. Carnitine palmitoyltransferase I in the outer membrane, and carnitine translocase plus carnitine palmitoyltransferase II in the inner membrane catalyse the transfer. Carnitine palmitoyltransferase I is inhibited by malonyl-CoA, an intermediate in fatty acid synthesis. In the liver of fasted, diabetic, or thyreotoxic animals this enzyme shows increased activity and less inhibition by malonyl-CoA. Peroxisomes also contain carnitine acyltransferases and a beta-oxidation enzyme system. This system is particularly active in the shortening of very long chain fatty acids. The carnitine acyltransferases of the peroxisomes presumably are active in the transfer of the shortened acyl-CoAs and the acetyl-CoA to the mitochondria for complete oxidation. The carnitine acyltransferases of the mitochondria can catalyse the formation of propionylcarnitine and branched chain acylcarnitines from branched chain amino acids, and methylthiopropionylcarnitine from methionine. Their formation may represent a \"security valve\" preventing acyl-CoA accumulation in the mitochondria. The liver, which normally releases carnitine for other tissues, releases the branched chain acylcarnitines even more easily. This may be important for the development of secondary carnitine deficiency in some inborn errors of metabolism which are accompanied by the accumulation of acyl-CoAs in the tissue.","PeriodicalId":15649,"journal":{"name":"Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie","volume":"28 5","pages":"297-301"},"PeriodicalIF":0.0,"publicationDate":"1990-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13352752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Primary carnitine deficiency. 原发性肉碱缺乏症。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

H R Scholte, R Rodrigues Pereira, P C de Jonge, I E Luyt-Houwen, M Hedwig, M Verduin, J D Ross

{"title":"Primary carnitine deficiency.","authors":"H R Scholte, R Rodrigues Pereira, P C de Jonge, I E Luyt-Houwen, M Hedwig, M Verduin, J D Ross","doi":"","DOIUrl":"","url":null,"abstract":"Carnitine deficiency can be defined as a decrease of intracellular carnitine, leading to an accumulation of acyl-CoA esters and an inhibition of acyl-transport via the mitochondrial inner membrane. This may cause disease by the following processes. A. Inhibition of the mitochondrial oxidation of long-chain fatty acids during fasting causes heart or liver failure. The latter may cause encephalopathy by hypoketonaemia, hypoglycaemia and hyperammonaemia. B. Increased acyl-CoA esters inhibit many enzymes and carriers. Long-chain acyl-CoA affects mitochondrial oxidative phosphorylation at the adenine nucleotide carrier, and also inhibits other mitochondrial enzymes such as glutamate dehydrogenase, carnitine acetyltransferase and NAD(P) transhydrogenase. C. Accumulation of triacylglycerols in organs increases stress susceptibility by an exaggerated response to hormonal stimuli. D. Decreased mitochondrial acetyl-export lowers acetylcholine synthesis in the nervous system. Primary carnitine deficiency can be defined as a genetic defect in the transport or biosynthesis of carnitine. Until now only defects at the level of carnitine transport have been discovered. The most severe form of primary carnitine deficiency is the consequence of a lesion of the carnitine transport protein in the brush border membrane of the renal tubules. This defect causes cardiomyopathy or hepatic encephalopathy usually in combination with skeletal myopathy. In a patient with cardiomyopathy and without myopathy, we found that carnitine transport at the level of the small intestinal epithelial brush border was also inhibited. The patient was cured by carnitine supplementation. Muscle carnitine increased, but remained too low. This suggests that carnitine transport in muscle is also inhibited. Carnitine transport in fibroblasts was normal, which disagrees with literature reports for similar patients.","PeriodicalId":15649,"journal":{"name":"Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie","volume":"28 5","pages":"351-7"},"PeriodicalIF":0.0,"publicationDate":"1990-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13352651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Carnitine: metabolism, function and clinical application. 肉毒碱:代谢、功能及临床应用。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

R Haeckel, E Kaiser, M Oellerich, N Siliprandi

引用次数: 0

Transport and functions of carnitine in muscles. 肉毒碱在肌肉中的运输和功能。

Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie Pub Date : 1990-05-01

N Siliprandi, F Di Lisa, R Menabó, M Ciman, L Sartorelli

引用次数: 0