Effects of Storage Time and Temperature on the Stability of Glutathione in Deproteinized Blood Sample
Shu-Kai Lin1, Shih-Meng Tsai2, Jung-Chih Huang1, Su-Chen Lee1, Szu-Hsien Wu3, Szu-Hua Wu4, Hsu Ma3, Jin-Teh Lin3 and Li-Yu Tsai1,4*
1. Divison of Clinical Biochemistry, Department of Clinical Laboratory, Kaohsiung Medical University Hospital, Taiwan, R.O.C.
2. Department of Public Health, School of Medicine, Kaohsiung Medical University, Taiwan, R.O.C.
3. Division of Plastic Surgery, Department of Surgery, Taipei Veterans General Hospital, Taiwan, R.O.C.
4. Department of Clinical Biochemistry, Faculty of Biomedical Laboratory Sciences,
Kaohsiung Medical University, College of Health Science, Kaohsiung, Kaohsiung, Taiwan, R.O.C.
(Received: April 1, 2005; Accepted: February 21, 2006)
Abstract
Glutathione is ubiquitous in eucaryotic cells and is implicated in many cellular functions. Release of reduced and oxidized glutathione (GSH and GSSG) into the plasma and the ratio of GSH/GSSG are considered a reliable index to evaluate the status of oxidative stress in biological systems. As storage temperatures and time periods have not been studied and discussed, we evaluated the effects of storage period and temperatures on the stability of GSH in blood samples by an automated capillary electropherograph system. After two-way ANOVA analysis, the result indicated that there were statistical significance between the GSH status and the storage period, and the GSH status and the preserved temperature as well. However, there was no statistical significance between samples with EDTA or with EDTA-NaF added as anticoagulant. Furthermore, no matter which freezing temperature (-20°C or -80°C) was used for storing the samples, the concentration of total GSH was quite consistent over the course of the study. We suggest that the alteration of the GSH status at room temperature should be due to not only the autoxidation of GSH but also the enzyme-catalyzed degradation of GSH and GSSG.
Key words: glutathione, blood, stability, autoxidation