Assessment of antioxidative ability in brain: technetium-99m-meso-HMPAO as an imaging agent for glutathione localization.
To visualize the regional localization of glutathione (GSH) in the brain, the relationship between the concentrations of tissue GSH and uptake of [99mTc]meso-hexamethyl propyleneamine oxime ([99mTc] meso-HMPAO) or [99mTc]d,l-hexamethyl propyleneamine oxime ([99mTc]d,l-HMPAO) was studied in mice.


METHODS
The uptake of [99mTc]meso-HMPAO in the mouse brain was decreased to 35% of control paralleling the decrease in GSH content by pre-loading of diethyl maleate (DEM), an agent to reduce GSH. In contrast, pre-treatment with DEM scarcely affected the 99mTc-d,l-HMPAO uptake in the brain.


RESULTS
The DEM treatment decreased the GSH content in liver, kidney, spleen, fat and lung but did not affect the uptake of [99mTc]meso-HMPAO in those tissues except lung. The images of rat brain acquired with a gamma camera showed a significant reduction of [99mTc]meso-HMPAO uptake by DEM treatment.


CONCLUSIONS
Technetium-99m-meso-HMPAO may be a potential tool to assess GSH content and to estimate antioxidative ability in the brain.
Sasaki
T
T
Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Japan.
Toyama
H
H
Oda
K
K
Ogihara-Umeda
I
I
Nishigori
H
H
Senda
M
M
D000818:Animals; D001921:Brain / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D008298:Maleates / Q000494:pharmacology; D051379:Mice; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010091:Oximes / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000378:metabolism; D019690:Technetium Tc 99m Exametazime; D014018:Tissue Distribution
D008298:Maleates; D015609:Organotechnetium Compounds; D010091:Oximes; D013438:Sulfhydryl Compounds; D019690:Technetium Tc 99m Exametazime; C014476:diethyl maleate; D005978:Glutathione