Résumé
ABSTRACT Considering that thiol-containing enzymes like kinases are critical for several metabolic pathways and energy homeostasis, we investigated the effects of cystine dimethyl ester and/or cysteamine administration on kinases crucial for energy metabolism in the kidney of Wistar rats. Animals were injected twice a day with 1.6 µmol/g body weight cystine dimethyl ester and/or 0.26 µmol/g body weight cysteamine from the 16th to the 20th postpartum day and euthanized after 12 hours. Pyruvate kinase, adenylate kinase, creatine kinase activities and thiol/disulfide ratio were determined. Cystine dimethyl ester administration reduced thiol/disulfide ratio and inhibited the kinases activities. Cysteamine administration increased the thiol/disulfide ratio and co-administration with cystine dimethyl ester prevented the inhibition of the enzymes. Regression between the thiol/disulfide ratio, and the kinases activities were significant. These results suggest that redox status may regulate energy metabolism in the rat kidney. If thiol-containing enzymes inhibition and oxidative stress occur in patients with cystinosis, it is possible that lysosomal cystine depletion may not be the only beneficial effect of cysteamine administration, but also its antioxidant and thiol-protector effect.
Sujets)
Animaux , Thiols , Mercaptamine/pharmacologie , Cystine/analogues et dérivés , Disulfures , Homéostasie/effets des médicaments et des substances chimiques , Rein/effets des médicaments et des substances chimiques , Adenylate kinase/analyse , Adenylate kinase/effets des médicaments et des substances chimiques , Reproductibilité des résultats , Rat Wistar , Creatine kinase/analyse , Creatine kinase/effets des médicaments et des substances chimiques , Cystine/pharmacologie , Agents de déplétion en cystine/pharmacologieRésumé
The effect of temperature, nerve tissue and certain constituents of the medium on multiplication of armadillo M. leprae was studied using Hanks BSS. An equal or better growth was seen at 30 degrees C and 10 degrees C compared to 37 degrees C. Multiplication was also seen at -20 degrees C. Adding cholesterol, foetal calf serum, cystine-HCl, sodium thioglycollate or nerve suspension and covering medium with liquid paraffin each showed beneficial effect. Hanks containing foetal calf serum, cholesterol with sodium thioglycollate or cystine-hydrochloride showed maximum multiplication. These combinations may be used for testing additional factors for further improvement of the medium.