Oxidative impairment of plasma and skeletal muscle sarcoplasmic reticulum in rats with adjuvant arthritis - effects of pyridoindole antioxidants.
OBJECTIVE
To study possible oxidation of proteins and lipids in plasma and sarcoplasmic reticulum (SR) from skeletal muscles and to assess the effects of pyridoindole antioxidants in rats with adjuvant arthritis (AA) and to analyze modulation of Ca-ATPase activity from SR (SERCA).


METHODS
SR was isolated by ultracentrifugation, protein carbonyls in plasma and SR were determined by ELISA. Lipid peroxidation was analyzed by TBARS determination and by mass spectrometry. ATPase activity of SERCA was measured by NADH-coupled enzyme assay. Tryptophan fluorescence was used to analyze conformational alterations.


RESULTS
Increase of protein carbonyls and lipid peroxidation was observed in plasma of rats with adjuvant arthritis. Pyridoindole antioxidant stobadine and its methylated derivative SMe1 decreased protein carbonyl formation in plasma, effect of stobadine was significant. Lipid peroxidation of plasma was without any effect of pyridoindole derivatives. Neither protein oxidation nor lipid peroxidation was identified in SR from AA rats. SERCA activity from AA rats increased significantly, stobadine and SMe1 diminished enzyme activity. Ratio of tryptophan fluorescence intensity in SR of AA rats increased and was not influenced by antioxidants.


CONCLUSIONS
Plasma proteins and lipids were oxidatively injured in rats with AA; antioxidants exerted protection only with respect to proteins. In SR, SERCA activity was altered, apparently induced by its conformational changes, as supported by study of tryptophan fluorescence. Stobadine and SMe1 induced a decrease of SERCA activity, elevated in AA rats, but they did not affect conformational changes associated with tryptophan fluorescence.
Strosova
Miriam
M
Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Slovakia.
Tomaskova
Iveta
I
Ponist
Silvester
S
Bauerova
Katarina
K
Karlovska
Janka
J
Spickett
Corinne M
CM
Horakova
Lubica
L
D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D001169:Arthritis, Experimental / Q000097:blood* / Q000473:pathology*; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D007211:Indoles / Q000627:therapeutic use*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D013058:Mass Spectrometry; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D010949:Plasma / Q000502:physiology*; D050050:Protein Carbonylation / Q000187:drug effects; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000502:physiology*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D007211:Indoles; D017392:Thiobarbituric Acid Reactive Substances; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases