Effects of D-aspartate treatment on D-aspartate oxidase, superoxide dismutase, and caspase 3 activities in frog (Rana esculenta) tissues.
Although D-aspartate (D-Asp) has been recognized to have a physiological role within different organs, high concentrations could elicit detrimental effects on those same organs. In this study, we examined the D-aspartate oxidase (D-AspO) activity and the expression of superoxide dismutase 1 (SOD1) and caspase 3 in different tissues of the frog Rana esculenta after chronic D-Asp treatment. Our in vivo experiments, consisting of intraperitoneal (ip) injections of D-Asp (2.0 micromol/g b.w.) in frogs for ten consecutive days, revealed that all examined tissues can take up and accumulate D-Asp. Further, in D-Asp treated frogs, i) the D-AspO activity significantly increased in all tissues (kidney, heart, testis, liver, and brain), ii) the SOD1 expression (antioxidant enzyme) significantly increased in the kidney, and iii) the caspase 3 level (indicative of apoptosis) increased in both brain and heart. Particularly, after the D-Asp treatment we found in both brain and heart (which showed the lowest SOD1 levels) a significant increase of the caspase 3 expression and, vice versa, in the kidney (which showed the highest SOD1 expression) a significant decrease of the caspase 3 expression. Therefore, we speculate that, in frog tissue, D-AspO plays an essential role in modulating the D-Asp concentration. In addition, exaggerated D-Asp concentrations activated SOD1 as cytoprotective mechanism in the kidney, whereas, in the brain and in the heart, where the antioxidant action of SOD1 is limited, caspase 3 was activated.
Burrone
Lavinia
L
Dipartimento di Scienze della Vita, Seconda Università degli Studi di Napoli, via Vivaldi 43, I-81100 Caserta, Italy.
Di Giovanni
Marcello
M
Di Fiore
M Maddalena
MM
Baccari
Gabriella Chieffi
GC
Santillo
Alessandra
A
D000818:Animals; D001921:Brain / Q000201:enzymology / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism*; D050804:D-Aspartate Oxidase / Q000378:metabolism*; D026603:D-Aspartic Acid / Q000008:administration & dosage*; D007274:Injections, Intraperitoneal; D007668:Kidney / Q000201:enzymology / Q000378:metabolism; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism; D011893:Rana esculenta; D013482:Superoxide Dismutase / Q000378:metabolism*; D000072105:Superoxide Dismutase-1
D026603:D-Aspartic Acid; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D050804:D-Aspartate Oxidase; D053148:Caspase 3