Autoxidation of brain homogenates from various animals as measured by thiobarbituric acid assay.
BACKGROUND
The TBARS assay has been well recognized for determination of lipid peroxidation and oxidative injury in biological samples including brain homogenates. In general, the homogenates are freshly prepared using rat brains as the tissue sources. In this study, we compared the rates of spontaneous lipid peroxidation in brain homogenates obtained from bovine, canine, hen, rat, and swine. In addition, the influences of lyophilization process and storage time up to six months at -20 degrees C without the freeze-thaw cycle were also determined in the swine brain preparations.


METHODS
The standard assay for thiobarbituric acid-reactive substances (TBARS) was performed at 37 degrees C, using spectrophotometry to quantify the malondialdehyde (MDA) content.


RESULTS
Rat brain homogenate exhibited the highest autoxidation rate (0.128+/-0.002 microM/min) whereas the bovine brain exhibited the lowest rate (0.032+/-0.001 microM/min). Swine brain homogenate could be kept at -20 degrees C up to 3 months without a significant increase in rate of autoxidation. Lyophilization caused a significant increase in the autoxidation rate of brain homogenate. However, the autoxidation rates of the lyophilized preparation were quite comparable throughout the six-month freezing time.


CONCLUSIONS
Swine brain was a good candidate for tissue source in the TBARS reaction. The homogenate could be kept in the lyophilized form under the storage condition at -20 degrees C without the freeze-thaw cycle in the dark for at least six months.
Pothiwong
Wimon
W
Faculty of Veterinary Sciences, Chulalongkorn University, Bangkok 10330, Thailand.
Laorpaksa
Areerat
A
Pirarat
Nopadon
N
Sirisawadi
Sujin
S
Intarapanya
Jantima
J
Jianmongkol
Suree
S
D000818:Animals; D001717:Birds; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001923:Brain Chemistry; D002417:Cattle; D003080:Cold Temperature; D004285:Dogs; D005612:Freeze Drying / Q000379:methods; D008315:Malondialdehyde / Q000032:analysis; D009929:Organ Size; D016877:Oxidants / Q000032:analysis*; D051381:Rats; D012034:Refrigeration / Q000379:methods; D013045:Species Specificity; D013048:Specimen Handling / Q000379:methods; D013552:Swine; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis*; D013997:Time Factors; D014021:Tissue Preservation / Q000379:methods
D016877:Oxidants; D017392:Thiobarbituric Acid Reactive Substances; D008315:Malondialdehyde