Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
2.
Diabetol Metab Syndr ; 10: 82, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30479668

RESUMEN

BACKGROUND: Neck circumference (NC) is associated with traditional cardiovascular risk factors (CVRF), but its usefulness to identify earlier atherogenic risk has been scarcely examined. Associations of NC with non-traditional CVRF were investigated in participants at low-to-moderate risk from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). METHODS: 807 individuals (35-54 years) without obesity, diabetes or cardiovascular disease was stratified into quartiles of NC (cut-off for men: 36.5; 37.9 and 39.5 cm; women: 31.4; 32.5 and 34 cm) and traditional and non-traditional risk factors (lipoprotein subfractions by Vertical Auto Profile, adiponectin, leptin, E-selectin) were compared across groups. In linear regression models, associations of NC with non-traditional risk factors were tested for the entire sample and for low-risk group (≤ 2 CVRF). RESULTS: In both sexes, BMI, waist circumference, systolic and diastolic blood pressure, fasting and 2-h plasma glucose, HOMA-IR, triglycerides, leptin, E-selectin, small dense LDL-cholesterol, IDL-cholesterol, VLDL3-cholesterol and TG/HDL ratio increased significantly, while HDL2-cholesterol and HDL3-cholesterol decreased across NC quartiles. In linear regression models, a direct association [ß(95% CI)] of NC with leptin [(0.155 (0.068-0.242); 0.147 (0.075-0.220)], E-selectin [(0.105 (0.032-0.177); 0.073 (0.006 to 0.140)] and small-dense LDL [(1.866 (0.641-3.091); 2.372 (1.391-3.353)] and an inverse association with HDL2-cholesterol [(- 0.519 (- 0.773 to - 0.266); - 0.815 (- 1.115 to 0.515)] adjusted for age were detected for men and women, respectively. CONCLUSION: Our findings indicate that measurement of NC may be useful for an earlier identification of unfavorable atherogenic metabolic profile in middle-aged individuals at lower cardiovascular risk level.

3.
Curr Med Chem ; 21(25): 2881-91, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24735362

RESUMEN

High-density lipoproteins (HDL) are classified as atheroprotective because they are involved in transport of cholesterol to the liver, known as "reverse cholesterol transport (RCT)" exerting antioxidant and anti-inflammatory activities. There is also evidence for cytoprotective, vasodilatory, antithrombotic, and anti-infectious activities for these lipoproteins. HDLs are known by structural, metabolic and biologic heterogeneity. Thus, different methods are able to distinguish several subclasses of HDL. Different separation techniques appear to support different HDL fractions as being atheroprotective or related with lower cardiovascular (CV) risk. However, HDL particles are not always protective. Modification of constituents of HDL particles (primarily in proteins and lipids) can lead to the decrease in their activity and induce proatherogenic properties, especially when isolated from patients with augmented systemic inflammation. According to available studies, it seems that HDL functionality may be a better therapeutic target than HDL cholesterol quantity; however, it is still disputable which subfractions are most beneficial. There is mounting evidence supporting HDL subclasses as an important biomarker to predict and/or reduce CV risk. In this review we discuss recent notices on atheroprotective and functional characteristic of different HDL subfractions. Also, we provide a brief overview of the different methods used by clinicians and researchers to separate HDL subfractions. Ongoing and future investigations will yield important new information if any given separation method might represent a 'gold standard', and which subfractions are reliable markers of CV risk and/or potential targets of novel, more focused, and effective therapies.


Asunto(s)
Lipoproteínas HDL/metabolismo , Animales , Enfermedades Cardiovasculares/metabolismo , Humanos , Factores de Riesgo
4.
Thromb Haemost ; 112(2): 323-31, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24763965

RESUMEN

Aspirin and statin therapy are mainstay treatments in patients with coronary artery disease (CAD). The relation between statin therapy, in vivo thromboxane (Tx) generation; a marker of inflammation, and blood thrombogenicity has never been explored. Urinary 11-dehydro (dh) TxB2 was determined in patients with suspected CAD on 325 mg daily aspirin therapy prior to undergoing cardiac catheterisation (n=281). Thrombogenicity was estimated by thrombelastographic measurement of thrombin-induced platelet-fibrin clot strength (TIP-FCS) and lipids/lipoproteins were determined by vertical density gradient ultracentrifugation/ELISA. The influence of statin therapy and dose was analysed by the atorvastatin equivalent dose (5-10 mg, 20-40 mg, or 80 mg daily). Statin therapy (n=186) was associated with a dose-dependent reduction in urinary 11-dh TxB2 (p=0.046) that was independent of LDL and apo B100 levels but was strongly related to TIP-FCS (p=0.006). By multivariate analysis, no statin therapy (n=95) and female gender were independently associated with high urinary 11-dh TxB2 [OR=2.95 (0.1.57-5.50, p=0.0007); OR=2.25 (1.24-4.05, p=0.007)], respectively. In aspirin-treated patients, statin therapy was independently and inversely associated with inflammation in a dose-dependent manner. Elevated 11-dh TxB2 was associated with a prothrombotic state indicated by high TIP-FCS. Our data suggest that measurement of urinary 11-dTxB2 may be a useful method to optimise statin dosing in order to reduce thrombotic risk.


Asunto(s)
Aspirina/administración & dosificación , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Mediadores de Inflamación/orina , Inhibidores de Agregación Plaquetaria/administración & dosificación , Tromboxano B2/análogos & derivados , Anciano , Biomarcadores/orina , Coagulación Sanguínea/efectos de los fármacos , Distribución de Chi-Cuadrado , Enfermedad de la Arteria Coronaria/sangre , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/orina , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Lípidos/sangre , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Modelos de Riesgos Proporcionales , Factores de Riesgo , Factores Sexuales , Tromboelastografía , Tromboxano B2/orina , Resultado del Tratamiento , Ultracentrifugación
5.
Curr Med Chem ; 21(25): 2892-901, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24606516

RESUMEN

The electrophoretic separation of lipoproteins on polyacrylamide gels enables the quantification of nonatherogenic and atherogenic plasma lipoproteins including small dense low density lipoprotein (sdLDL) particles, which represent the atherogenic lipoprotein subpopulations in plasma. This methodology could help distinguish between nonatherogenic hyperlipidemia, normolipidemia with an atherogenic lipoprotein profile, non-atherogenic normolipidemia, and atherogenic hyperlipidemia. According to our pilot research of a normolipidemic population, the atherogenic lipoprotein profile might be present in about 6% of normolipidemic young healthy individuals. Therefore, if confirmed by other studies, it will be necessary to consider a different diagnostic approach and risk stratification for patients with atherogenic normolipidemia (as well as non-atherogenic hypercholesterolemia).


Asunto(s)
Aterosclerosis/metabolismo , Dislipidemias/metabolismo , Humanos , Hipercolesterolemia/metabolismo , Lipoproteínas/metabolismo , Factores de Riesgo
6.
Int J Clin Pract ; 66(8): 800-812, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22805272

RESUMEN

Aims: The aim of this analysis was to assess the overall safety and tolerability profiles of various statins + ezetimibe vs. statin monotherapy and to explore tolerability in sub-populations grouped by age, race, and sex. Methods: Study-level data were combined from 27 double-blind, placebo-controlled or active-comparator trials that randomized adult hypercholesterolemic patients to statin or statin + ezetimibe for 6-24 weeks. In the full cohort, % patients with AEs within treatment groups (statin: N = 10,517; statin + ezetimibe: N = 11,714) was assessed by logistic regression with terms for first-/second-line therapy (first line = drug-naïve or rendered drug-naïve by washout at study entry; second line = ongoing statin at study entry or statin run-in), trial within first-/second-line therapy, and treatment. The same model was fitted for age (< 65, ≥ 65 years), sex, race (white, black, other) and first-/second-line subgroups with additional terms for subgroup and subgroup-by-treatment interaction. Results: In the full cohort, the only significant difference between treatments was consecutive AST or ALT elevations ≥ 3 × upper limit of normal (ULN) (statin: 0.35%, statin + ezetimibe: 0.56%; p = 0.017). Significantly more subjects reported ≥ 1 AE; drug-related, hepatitis-related and gastrointestinal-related AEs; and CK elevations ≥ 10 × ULN (all p ≤ 0.008) in first-line vs. second-line therapy studies with both treatments. AEs were generally similar between treatments in subgroups, and similar rates of AEs were reported within age and race subgroups; however, women reported generally higher AE rates. Conclusions: In conclusion, in second-line studies, ongoing statin treatment at study entry likely screened out participants for previous statin-related AEs and tolerability issues. These results describe the safety profiles of widely used lipid-lowering therapies and encourage their appropriate and judicious use in certain subpopulations.

7.
Int J Clin Pract ; 63(6): 903-11, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19490201

RESUMEN

Achieving adequate control of cardiovascular risk in type 2 diabetes mellitus (DM) is crucially important; however, the atherogenic dyslipidaemia (including low high-density lipoprotein cholesterol and hypertriglyceridaemia) typically encountered in type 2 DM is often managed inadequately. Evidence from the Fenofibrate Intervention and Event Lowering in Diabetes study suggests that fenofibrate reduces the risk of long-term macrovascular and microvascular type 2 diabetic complications, especially in patients demonstrating features of the metabolic syndrome. Fenofibrate represents a useful treatment option for controlling cardiovascular risk in type 2 diabetes patients in the community setting.


Asunto(s)
Diabetes Mellitus Tipo 2/prevención & control , Angiopatías Diabéticas/prevención & control , Fenofibrato/uso terapéutico , Hipolipemiantes/uso terapéutico , Servicios de Salud Comunitaria , Quimioterapia Combinada , Humanos , Síndrome Metabólico/prevención & control , Factores de Riesgo
8.
Int J Clin Pract ; 62(8): 1246-54, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18564201

RESUMEN

Atherosclerosis is a chronic, progressive, inflammatory disease with a long asymptomatic phase. Disease progression can lead eventually to the occurrence of acute cardiovascular events such as myocardial infarction, unstable angina pectoris and sudden cardiac death. While the disease is still in a subclinical stage, however, the presence of atherosclerosis can be identified by several methods, including coronary angiography, intravascular ultrasonography, B-mode ultrasonography, computed tomography and magnetic resonance imaging. Based on the results of imaging studies, statin therapy can slow, halt or even reverse the progression of atherosclerotic disease, depending on the intensity of treatment. Whether to screen and treat patients for subclinical atherosclerosis remains controversial. Although atheromatous plaque burden reduction has not yet been definitively correlated with significant decreases in risk for acute coronary events in asymptomatic patients, statin therapy contributes significantly to the risk reduction observed in clinical trials in patients with and without overt coronary disease.


Asunto(s)
Aterosclerosis/diagnóstico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Adulto , Anciano , Aterosclerosis/complicaciones , Aterosclerosis/tratamiento farmacológico , Enfermedades de las Arterias Carótidas/prevención & control , Enfermedad Coronaria/prevención & control , Progresión de la Enfermedad , Diagnóstico Precoz , Femenino , Humanos , Estilo de Vida , Masculino , Tamizaje Masivo/organización & administración , Persona de Mediana Edad , Selección de Paciente , Valor Predictivo de las Pruebas , Factores de Riesgo , Conducta de Reducción del Riesgo
10.
Arch Fam Med ; 9(2): 195-7, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10693739

RESUMEN

Splenic infarction is a clinical entity seldom encountered. The most frequent causes of splenic infarction include thromboembolic phenomena, hematologic malignant neoplasms, and vasculitides. We describe a patient who sustained splenic infarction secondary to diabetes-induced, small-vessel atherosclerotic disease.


Asunto(s)
Angiopatías Diabéticas/complicaciones , Angiopatías Diabéticas/diagnóstico , Infarto del Bazo/diagnóstico , Infarto del Bazo/etiología , Adulto , Diagnóstico Diferencial , Femenino , Humanos
11.
Obstet Gynecol ; 91(6): 909-16, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9610995

RESUMEN

OBJECTIVE: To identify risk factors associated with poorer immediate neonatal outcomes among growth-restricted neonates. METHODS: Records of all 530 growth-restricted neonates born between January 1989 and February 1995 were reviewed. Outcomes included resuscitation measures, Apgar scores, and umbilical blood gas values. Neonates were assigned to one of six anesthetic groups, and outcomes were compared. Predictors of poorer outcomes were examined using logistic and linear regression. RESULTS: Neonates exposed to general anesthesia were more likely to be intubated (37.9% versus 4.1%, P < .001, Pearson chi2) and had lower mean 1- (4.0 versus 7.0) and 5-minute (6.5 versus 8.4) Apgar scores (P < .01, Scheffé) than those in all other anesthetic groups. They also had significantly lower umbilical artery (UA) pH values than neonates who received nalbuphine, epidural, or no anesthesia (7.21 versus 7.28, 7.26, 7.29, respectively; P < .01, Scheffé). Factors that significantly and independently predicted intubation among all neonates included exposure to general anesthesia (odds ratio [OR] 4.1; 95% confidence interval [CI] 1.9, 8.9) and lower infant weight (OR 10.1 per kg decrease; CI 5.1, 20). Factors predicting UA pH at most 7.15 included preeclampsia (OR 3.0; CI 1.5, 5.9) and older maternal age (OR 1.3 per 5 years; CI 1.02, 1.64); vertex delivery (OR 0.5; CI 0.2, 0.9) was protective. Factors predicting a 5-minute Apgar less than 7 were meconium (OR 1.5 per category going from none to terminal to light to heavy; CI 1.04, 2.3), general anesthesia (OR 6.9; CI 2.6, 18.2), lower infant weight (OR 16.5 per kg decrease; CI 7.8, 34.5), and vaginal breech delivery (OR 7.0; CI 1.8, 28.6); cesarean delivery (OR 0.2; CI 0.08, 0.66) was protective. Spontaneous vertex delivery raised the UA pH, and preeclampsia, amnioinfusion, breech delivery, and general anesthesia significantly and independently lowered the UA pH among all neonates. For infants delivered by cesarean, "fetal distress," preeclampsia, previous spontaneous abortion, failed forceps use, and nalbuphine significantly and independently predicted lower UA pH. CONCLUSION: Risk factors for poorer immediate neonatal outcomes among growth-restricted neonates include preeclampsia, fetal distress, breech delivery, forceps use, nalbuphine during labor, lower infant weight, and general anesthesia.


Asunto(s)
Anestesia General , Anestesia Obstétrica , Puntaje de Apgar , Sangre Fetal/metabolismo , Recién Nacido Pequeño para la Edad Gestacional/fisiología , Resucitación , Analgésicos Opioides/efectos adversos , Anestesia General/efectos adversos , Anestesia Obstétrica/efectos adversos , Estudios de Casos y Controles , Cesárea/efectos adversos , Parto Obstétrico/efectos adversos , Parto Obstétrico/métodos , Femenino , Retardo del Crecimiento Fetal/epidemiología , Humanos , Concentración de Iones de Hidrógeno , Recién Nacido , Nalbufina/efectos adversos , Preeclampsia/epidemiología , Embarazo , Análisis de Regresión , Factores de Riesgo
12.
Stat Szle ; 74(5-6): 438-59, 1996.
Artículo en Húngaro | MEDLINE | ID: mdl-12347669

RESUMEN

PIP: The distribution of refugees arriving in Hungary between 1988 and 1994, mainly from Romania and Yugoslavia, is analyzed by citizenship, ethnicity, age, and sex. (SUMMARY IN ENG)^ieng


Asunto(s)
Factores de Edad , Demografía , Etnicidad , Refugiados , Factores Sexuales , Cultura , Países Desarrollados , Emigración e Inmigración , Europa (Continente) , Europa Oriental , Geografía , Hungría , Población , Características de la Población , Dinámica Poblacional , Migrantes
13.
Arch Fam Med ; 5(1): 48-51, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8542054

RESUMEN

Turner's syndrome is one of the most frequently occurring chromosomal defects and is associated with a well-characterized set of anatomic malformations. We studied clinical findings in an elderly woman who was diagnosed as having cytogenetically proved Turner's syndrome late in life. Because most patients with Turner's syndrome have normal intelligence and mild phenotypic abnormalities, the condition was never properly diagnosed in many affected women born earlier in this century. Given the range of clinical abnormalities and physiologic deficits to which these women are predisposed, it remains important to diagnose and treat them accurately irrespective of age.


Asunto(s)
Síndrome de Turner/diagnóstico , Síndrome de Turner/genética , Anciano , Diagnóstico Diferencial , Femenino , Humanos , Cariotipificación
15.
J Pediatr ; 123(3): 427-30, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8355121

RESUMEN

A comatose male newborn infant with congenital lactic acidosis caused by pyruvate decarboxylase deficiency was treated with dichloroacetate (DCA), which stimulated an 88% drop in serum lactate concentration and reversed his coma. The response to DCA was temporary and the lactic acidosis worsened until his death, but DCA may confer more lasting benefit in less severely affected infants.


Asunto(s)
Acidosis Láctica/congénito , Acidosis Láctica/tratamiento farmacológico , Ácido Dicloroacético/uso terapéutico , Piruvato Descarboxilasa/deficiencia , Errores Innatos del Metabolismo del Piruvato/tratamiento farmacológico , Acidosis Láctica/etiología , Humanos , Recién Nacido , Masculino , Errores Innatos del Metabolismo del Piruvato/complicaciones
16.
Comp Biochem Physiol B ; 100(3): 547-54, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1839977

RESUMEN

1. In the absence of exogenous Ca(II), Pi induces a swelling change that is kinetically first order with k = 1.08 +/- 0.1 min-1. The first-order rate constant is independent of [Pi] over the range of 0.5-45 mM. 2. In the presence of exogenous substrate, the volume change induced by Pi is monophasic and can be reversed by ADP. 3. The swelling process and the approach to steady state is accompanied by controlled losses of both K+ and Mg(II) from within the mitochondria. 4. The loss of K+ is biphasic as a function of time with ki = 14.1 +/- 1.6 and k2 = 4.4 +/- 0.34 nmol min-1 mg mitochondria-1. 5. The loss of Mg(II) is monophasic and the rate at which this cation is released decreases as a function of time. Ca(II) fluxes are not involved in the volume occurring secondary to Pi uptake. 6. In the absence of exogenous substrate, Pi induces a triphasic change in mitochondrial volume. 7. The sequence of volume changes corresponds to an initial first-order swelling secondary to the addition of Pi, a contraction apparently triggered by the loss of approximately 85% of total intra-mitochondrial Mg(II), and a second larger swelling phase that cannot be reversed with ADP. 8. The Pi-induced swelling of chick heart mitochondria is not inhibited by EGTA and does not depend on the provision of exogenous Ca(II). 9. The Ca(II) and Mg(II) ions released from within the mitochondria are responsible for activating divalent cation-dependent ATPases which cosediment with isolated chick heart mitochondria.


Asunto(s)
Mitocondrias Cardíacas/metabolismo , Dilatación Mitocondrial , Fosfatos/farmacología , Adenosina Trifosfatasas/metabolismo , Animales , Calcio/metabolismo , Pollos , Ácido Egtácico , Activación Enzimática , Cinética , Magnesio/metabolismo , Mitocondrias Cardíacas/efectos de los fármacos , Oligomicinas/farmacología , Ósmosis , Consumo de Oxígeno , Potasio/metabolismo
17.
Arch Biochem Biophys ; 276(1): 199-211, 1990 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2153362

RESUMEN

Heart mitochondria isolated from 14- to 21-day-old chicks are highly coupled and often have respiratory control ratio (RCR) values exceeding 100. This paper presents data from a study of some of the properties of these mitochondria. The studies show that: (a) The ADP:O ratios and the state 4 rates of respiration are highly dependent upon the concentration of mitochondria at which these parameters are measured. (b) The mitochondrial isolate is contaminated with at least two divalent cation-stimulated ATPase, of which one is the F1F0-ATPase of broken mitochondria. (c) The oligomycin-sensitive component of state 4 respiration is completely inhibited by ethylene glycol bis(beta-amino-ethylether) N,N'-tetraacetic acid (EGTA). This inhibition is biphasic and attributable to the differential affinity of EGTA for Ca(II) and Mg(II). (d) Ca(II) and Mg(II) stimulate state 4 respiration, thereby depressing RCR values. These cations also decrease ADP:O ratios from greater than or equal to 3.25 to 3.0 for some NAD-linked substrates. (e) Uncoupled (i.e., oligomycin-insensitive) state 4 respiration can be abolished by treating the mitochondria with Nagarse and by preincubating mitochondria with exogenous substrate. (f) The ADP:O ratios obtained when these heart mitochondria oxidize pyruvate/malate, alpha-ketoglutarate, and beta-hydroxybutyrate are fractional and significantly greater than 3.0.


Asunto(s)
Adenosina Difosfato/metabolismo , Mitocondrias Cardíacas/metabolismo , Fosforilación Oxidativa , Consumo de Oxígeno , Ácido 3-Hidroxibutírico , Adenosina Trifosfatasas/metabolismo , Animales , Carbonil Cianuro m-Clorofenil Hidrazona/farmacología , Pollos , Ácido Egtácico/farmacología , Complejo IV de Transporte de Electrones/metabolismo , Etilmaleimida/farmacología , Glutamatos/metabolismo , Hidroxibutiratos/metabolismo , Ácidos Cetoglutáricos/metabolismo , Cinética , Magnesio/farmacología , Colagenasa Microbiana , Mitocondrias Cardíacas/efectos de los fármacos , Fosforilación Oxidativa/efectos de los fármacos , Factores de Acoplamiento de la Fosforilación Oxidativa/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Piruvatos/metabolismo , Succinatos/metabolismo
18.
J Biol Chem ; 263(3): 1151-6, 1988 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-3335535

RESUMEN

The steady state levels of mitochondrial acyl-CoAs produced during the oxidation of pyruvate, alpha-ketoisovalerate, alpha-ketoisocaproate, and octanoate during state 3 and state 4 respiration by rat heart and liver mitochondria were determined. Addition of carnitine lowered the amounts of individual short-chain acyl-CoAs and increased CoASH in a manner that was both tissue- and substrate-dependent. The largest effects were on acetyl-CoA derived from pyruvate in heart mitochondria using either state 3 or state 4 oxidative conditions. Carnitine greatly reduced the amounts of propionyl-CoA derived from alpha-ketoisovalerate, while smaller effects were obtained on the branched-chain acyl-CoA levels, consistent with the latter acyl moieties being poorer substrates for carnitine acetyltransferase and also poorer substrates for the carnitine/acylcarnitine translocase. The levels of acetyl-CoA in heart and liver mitochondria oxidizing octanoate during state 3 respiration were lower than those obtained with pyruvate. The rate of acetylcarnitine efflux from heart mitochondria during state 3 (with pyruvate or octanoate as substrate, in the presence or absence of malate with 0.2 mM carnitine) shows a linear response to the acetyl-CoA/CoASH ratio generated in the absence of carnitine. This relationship is different for liver mitochondria. These data demonstrate that carnitine can modulate the aliphatic short-chain acyl-CoA/CoA ratio in heart and liver mitochondria and indicate that the degree of modulation varies with the aliphatic acyl moiety.


Asunto(s)
Acilcoenzima A/metabolismo , Carnitina/farmacología , Coenzima A/metabolismo , Mitocondrias Cardíacas/metabolismo , Mitocondrias Hepáticas/metabolismo , Animales , Caprilatos/metabolismo , Hemiterpenos , Cetoácidos/metabolismo , Masculino , Mitocondrias Cardíacas/efectos de los fármacos , Mitocondrias Hepáticas/efectos de los fármacos , Piruvatos/metabolismo , Ácido Pirúvico , Ratas , Ratas Endogámicas
19.
J Biol Chem ; 261(29): 13698-703, 1986 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-3759988

RESUMEN

The efflux of individual short-chain and medium-chain acylcarnitines from rat liver, heart, and brain mitochondria metabolizing several substrates has been measured. The acylcarnitine efflux profiles depend on the substrate, the source of mitochondria, and the incubation conditions. The largest amount of any acylcarnitine effluxing per mg of protein was acetylcarnitine produced by heart mitochondria from pyruvate. This efflux of acetylcarnitine from heart mitochondria is almost 5 times greater with 1 mM than 0.2 mM carnitine. Apparently the acetyl-CoA generated from pyruvate by pyruvate dehydrogenase is very accessible to carnitine acetyltransferase. Very little acetylcarnitine effluxes from heart mitochondria when octanoate is the substrate except in the presence of malonate. Acetylcarnitine production from some substrates peaks and then declines, indicating uptake and utilization. The unequivocal demonstration that considerable amounts of propionylcarnitine or isobutyrylcarnitine efflux from heart mitochondria metabolizing alpha-ketoisovalerate and alpha-keto-beta-methylvalerate provides evidence for a role (via removal of non-metabolizable propionyl-CoA or slowly metabolizable acyl-CoAs) for carnitine in tissues which have limited capacity to metabolize propionyl-CoA. These results also show propionyl-CoA must be formed during the metabolism of alpha-ketoisovalerate and that extra-mitochondrial free carnitine rapidly interacts with matrix short-chain aliphatic acyl-CoA generated from alpha-keto acids of branched-chain amino acids and pyruvate in the presence and absence of malate.


Asunto(s)
Encéfalo/metabolismo , Carnitina/análogos & derivados , Mitocondrias Cardíacas/metabolismo , Mitocondrias Hepáticas/metabolismo , Mitocondrias/metabolismo , Animales , Carnitina/metabolismo , Cinética , Masculino , Especificidad de Órganos , Ratas , Ratas Endogámicas , Relación Estructura-Actividad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...