Vascular non-protein thiols: prooxidants or antioxidants in atherogenesis?
Abstract-cell-mediated lipoprotein oxidation may be due to generation of non-protein thiols (NP-SH) from cystine with formation of oxidizing species. However, NP-SH, especially GSH, may also exert antioxidant effects in vitro and in vivo. To further investigate whether vascular NP-SH could be prooxidants or antioxidants in atherosclerosis, we have correlated the aortic content of NP-SH with that of lipoperoxides in 10 rabbits fed on a fat-enriched atherogenic diet for 9 weeks. As compared to 7 control rabbits, aortic NP-SH and lipoperoxides were significantly increased in the fat-fed animals. The levels of NP-SH were strongly and inversely correlated with those of lipid peroxidation in the atherosclerotic aorta (r(s) -0.92, P < 0.0001 for thiobarbituric acid reactive substances, and r(s) -0.80, P < 0.01 for fluorescent damage products of lipid peroxidation). A similar trend was evident also in the control rabbits (r(s) -0.60 for both indices of lipid peroxidation). Thus, the present data suggest that vascular NP-SH exert significant antioxidant-antilipoperoxidative effects in vivo especially in fat diet-related atherogenic conditions.
Lapenna
D
D
Dipartimento di Medicina e Scienze dell'Invecchiamento, Universita' G. d'Annunzio, Facolta' di Medicina e Chirurgia, Italy.
de Gioia
S
S
Porreca
E
E
Pierdomenico
S D
SD
Ciofani
G
G
Bruno
C
C
Di Ilio
C
C
Cuccurullo
F
F
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001011:Aorta / Q000502:physiology; D001161:Arteriosclerosis / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D004036:Diet, Atherogenic; D004195:Disease Models, Animal; D015227:Lipid Peroxidation; D008297:Male; D011817:Rabbits; D013438:Sulfhydryl Compounds / Q000378:metabolism*
D000975:Antioxidants; D013438:Sulfhydryl Compounds; D002784:Cholesterol