Nitrosative stress and glutathione redox system in four different tissues of alloxan-induced hyperglycemic animals.
In hyperglycemia a reduction of the antioxidant power and an increased production of nitric oxide (NO) have been reported. Because nitrotyrosine (NT) is a stable end-product of nitrosative stress, assessment of its concentration is considered a useful marker of NO-dependent damages. The level of nitrotyrosine and four antioxidant parameters were evaluated in pancreas, kidney, heart, and testis of alloxan-induced hyperglycemic rabbits after 6 and 10 weeks of persistent hyperglycemia. In hyperglycemic groups, the level of nitrotyrosine was elevated by 44 and 39%, 92 and 95%, and by 155 and 138% in pancreas, kidney, and heart, respectively, while the testicular level of NT was unaffected. The pancreatic activities of glutathione peroxidase (GPX) and catalase (CAT) increased by 64% and 50%, and by 49 and 70%, while the level of glutathione (GSH) and the activity of glutathione reductase (GR) decreased by 37 and 38%, and by 57 and 42%. In the kidney the significant changes occurred as decreases in GR activity and GSH level by 36 and 35%, and by 28 and 23%, respectively. In the heart, a significant increase in CAT activity by 90 and 23% was observed. In the testis, the CAT, GPX, and GR activities were increased by 67 and 77%, 72 and 27%, and 33 and 28%, respectively, while the level of GSH was increased by 22 and 17%. These results confirm that tissues from hyperglycemic animals differ in neutralizing nitrosative stress. This may be due to different adaptive responses of their glutathione redox cycle.
Department of Medicinal Chemistry, Medical University of Lublin, Lublin, Poland. anna.gumieniczek@umlub.pl
Anna
A
Gumieniczek
Marta
M
Wilk
D000818:Animals; D002374:Catalase / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D005978:Glutathione / Q000737:chemistry; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006943:Hyperglycemia / Q000378:metabolism; D007668:Kidney / Q000737:chemistry*; D008297:Male; D009206:Myocardium / Q000737:chemistry*; D010084:Oxidation-Reduction; D046790:Pancreas, Exocrine / Q000737:chemistry*; D011817:Rabbits; D013737:Testis / Q000737:chemistry*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis
C002744:3-nitrotyrosine; D014443:Tyrosine; D002374:Catalase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005978:Glutathione