Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where M. L Kluppel is active.

Publication


Featured researches published by M. L Kluppel.


Cell Biochemistry and Function | 1997

Effect of methotrexate (MTX) on NAD(P)+ dehydrogenases of HeLa cells: malic enzyme, 2-oxoglutarate and isocitrate dehydrogenases

Nilce N. Caetano; Annibal P. Campello; Eva Gunilla Skare Carnieri; M. L Kluppel; Maria Benigna M. Oliveira

The effects of methotrexate (MTX) on oxygen uptake by permeabilized HeLa cells were evaluated. MTX did not inhibit state III respiration when the oxidizable substrate was succinate, but when the substrates were 2‐oxoglutarate or isocitrate the respiration decreased about 50 per cent at 1·0 mM concentration of the drug. This effect was explained by inhibition of 2‐oxoglutarate and isocitrate dehydrogenases by MTX. No effect was observed on succinate dehydrogenase. An evaluation of the effects of MTX on malic enzyme activity as measured by pyruvate plus lactate production in intact cells supplied with malate showed a decrease of about 40 per cent in metabolite production using 0·4 mM MTX. HeLa cell malic enzyme, as observed for other tumour cells, is compartmentalized in mitochondria and cytosol, and is another example of a dehydrogenase inhibited by MTX.


International Journal of Cardiology | 1995

Amiodarone effects on membrane organization evaluated by fluorescence polarization

M.C. Antunes-Madeira; Romeu A. Videira; M. L Kluppel; Vítor M.C. Madeira

The effects of amiodarone (0-100 microM) on the physical state of synthetic and native membranes were investigated by fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH), probing the bilayer core, and of its anionic propionic acid derivative (DPH-PA), probing the outer regions of the bilayer. In the gel phase of dimyristoylphosphatidylcholine (DMPC) bilayers, amiodarone broadens the transition profile and shifts the phase transition midpoint to lower temperature values, as evaluated by both probes. On the other hand, the drug orders the fluid phase of the lipid either in hydrophobic core or in the outer regions of the bilayer, as detected by DPH and DPH-PA, respectively. The effects of amiodarone on the thermotropic behaviour of DPPC confirm and extend data in DMPC. Cholesterol concentration modulates to a great extent the effects of amiodarone in the fluid phase of DMPC. Thus, both probes, DPH and DPH-PA, detect either ordering effects of amiodarone for low cholesterol concentrations (< or = 20 mol%) or disordering amiodarone effects at higher cholesterol levels (> 20 mol%). In agreement with the results in models of synthetic lipids, the ordering effects of amiodarone in fluid native membranes of mitochondria and brain microsomes are depressed with the increase in intrinsic cholesterol. The ordering effects in mitochondria may induce bioenergetic dysfunctions and consequently disturbances in the electromechanic functioning of myocardium.


Biochemical Pharmacology | 1976

Possible mechanism of action of perhexiline maleate on heart mitochondria.

M. L Kluppel; L.C.Vieira Lopes; O Silveira; Annibal P. Campello

Abstract Oxidative phosphorylation and oxidation of NAD+-linked substrates by rat heart mitochondria were depressed by 6.75 × 10−5 M perhexiline maleate (PM), while the succinate oxidation was increased to 320 per cent activity. The drug had no effect on mitochondrial succinic and malate dehydrogenase, NADH-ferricyanide reductase and NADH-CoQ reductase (340 nm); therefore, NADH-oxidase, mitochondrial electron-transporting particles (EP1), NADH-CoQ reductase (550 nm) and aspartate aminotransferase were inhibited. It is suggested that PM would act. preventing the reoxidation of NADH+ + H+ through the respiratory chain.


Arquivos De Neuro-psiquiatria | 1997

Caracterizaçäo de miopatias mitocondriais através da avaliaçäo das atividades enzimáticas envolvidas no metabolismo energético

Fábio Cesar Pedroso; Annibal P. Campello; Lineu Cesar Werneck; M. L Kluppel

The activities of the enzymes NADH dehydrogenase, NADH cytochrome e reductase, succinate dehydrogenase, succinate cytochrome e reductase, cytochrome c oxidase and citrate synthase in normal and sick human skeletal muscle mitochondria were determined. A control group was formed by 13 normal people and without using continuous medication. The patient group was formed by 10 people whose pathological diagnosis indicated suspicion of mitochondrial myopathy. A decrease in the activity of the enzymes in all patient was observed: 7 with abnormality in all the tested enzymes; 2 with deficiencies in all the enzymes except cytochrome e oxidase; and 1 with dysfunction only in the activities of succinate dehydrogenase and succinate cytochrome e reductase. The results indicate multiple or combined deficiencies in the respiratory chain, besides dysfunction of citrate synthase in 9 patients. In one exceptional case, the enzymatic deficiency was restricted to complex II. It is possible to conclude that the methodology used herein is adequate and easily applicable to clinical objectives, and that the results obtained allow characterization of the deficient mitochondrial enzymatic complexes, thus showing that the origin of the diseases is an energetic metabolic dysfunction.Foi determinada a atividade das enzimas NADH desidiogenase, NADH citocromo e redutase, succinato desidiogenase, succinato citocromo e redutase, citocromo e oxidase e citrato sintase em mitocondrias de musculo esqueletico humano normal e doente (suspeito de miopatia mitocondrial). O grupo controle foi constituido de 13 individuos normais e que nao faziam uso continuo de farrnacos. O grupo doente era constituido de 10 pacientes cujo diagnostico anatomopatologico indicava suspeita de miopatia mitocondrial. Observou-se reducao na atividade das enzimas em todos os pacientes: 7 com anormalidades em todas as enzimas ensaiadas; 2 com deficiencias em todas as enzimas exceto na citocromo e oxidase; e 1 paciente com disfuncao apenas na atividade da succinato desidiogenase e succinato citocromo e redutase. Este perfil possibilitou caracterizar multiplas deficiencias ou deficiencia combinada da cadeia respiratoria, alem da disfuncao na citrato sintase em 9 pacientes. Um dos casos constituiu excecao, sendo a deficiencia enzimatica restrita ao complexo II. Foi possivel concluir que a metodologia usada e adequada e facilmente aplicavel aos objetivos clinicos. Os resultados obtidos possibilitam a caracterizacao dos complexos enzimaticos mitocondriais deficientes, mostrando que tais enfermidades sao originadas de disfuncao no metabolismo energetico.


Cell Structure and Function | 1994

Alterations induced by citrinin in cultured kidney cells

Generoso M. Chagas; M. L Kluppel; Annibal P. Campello; Dorly de Freitas Buchi; Maria Benigna M. Oliveira


Cell Biochemistry and Function | 1989

Methotrexate: studies on cellular metabolism. II--Effects on mitochondrial oxidative metabolism and ion transport.

Nair Seiko Yamamoto; Luiz Carlos Vieira Lopes; Annibal P. Campello; M. L Kluppel


Cell Biochemistry and Function | 1986

Biochemical aspects of the mechanism of action of antiarrhythmic drugs on mitochondria. VII. Effect on energy-linked reactions and on membrane potential

M. L Kluppel; Hélcio Resende Borba; O Silveira; Luiz Carlos Vieira Lopes; Annibal P. Campello


Arquivos de biologia e tecnologia | 1986

Effect of amiodarone on mitochondrial energy-linked reactions and on mitochondríal morphology

Maria Helena C. P. de Meira Guerreiro; Luiz Carlos Vieira Lopes; Annibal P. Campello; M. L Kluppel


Arquivos de biologia e tecnologia | 1986

Effect of amiodarone on mitochondrial membranes

Maria Helena C. P. de Meira Guerreiro; Annibal P. Campello; Luiz Carlos Vieira Lopes; M. L Kluppel


Arq. biol. tecnol | 1983

Biochemical aspects of the mechanism of action of anti-arrhythmic drugs on mitochondria. III Effect on NADH-succinate cytochrome c reductase (Complexes I-II-III).

J. C Fortes; M. L Kluppel; Luiz Carlos Vieira Lopes; Annibal de Paiva Campello

Collaboration


Dive into the M. L Kluppel's collaboration.

Top Co-Authors

Avatar

Annibal P. Campello

Federal University of Paraná

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

O Silveira

Federal University of Paraná

View shared research outputs
Top Co-Authors

Avatar

Hélcio Resende Borba

Universidade Federal Rural do Rio de Janeiro

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge