High sulfhydryl content in turtle erythrocytes: is there a relation with resistance to hypoxia?
Glutathione concentration in the erythrocytes of the fresh-water turtle Phrynops hilarii, as determined by the enzymic recycling method is 1.9 +/- 0.2 mM. The erythrocyte non-protein -SH, NPSH, content, as determined by the 5,5' dithiobis(2-nitrobenzoic acid), DTNB, reducing capacity is 4.6 +/- 0.8 mM. The total DTNB reducing capacity in the erythrocytes, including hemoglobin, is 26 +/- 5 mM. Incubation with oxidized glutathione, greatly increases the electrophoretic mobility of both hemoglobin components present in the erythrocytes of Phrynops hilarii, indicating the formation of mixed disulphides with glutathione. The high --SH content in the erythrocytes of P. hilarii might be part of a redox buffering principally an antioxidant mechanism involved in resistance to hypoxia, possibly along the hypoxic period as well as during reperfusion with oxygen.
D000818:Animals; D002021:Buffers; D004912:Erythrocytes / Q000378:metabolism*; D005978:Glutathione / Q000031:analogs & derivatives / Q000097:blood*; D019803:Glutathione Disulfide; D000860:Hypoxia / Q000097:blood*; D010084:Oxidation-Reduction; D014426:Turtles / Q000097:blood*
D002021:Buffers; D005978:Glutathione; D019803:Glutathione Disulfide