Related Experiment Videos
Brain chemiluminescence and oxidative stress in hyperthyroid rats
A M Adamo1, S F Llesuy, J M Pasquini
1Departamento de Quimica Biologica-IQUIFIB, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires-CONICET, Argentina.
The Biochemical Journal
|October 1, 1989
Summary
Hyperthyroidism in newborn rats increased brain metabolism and oxidative stress, evidenced by higher oxygen uptake and antioxidant enzyme activity. This condition shortened lifespan, suggesting a link between oxidative damage and premature aging.
Area of Science:
- Neuroscience
- Endocrinology
- Biochemistry
Background:
- Hyperthyroidism is associated with increased metabolic rate.
- The impact of hyperthyroidism on brain oxidative stress and lifespan is not fully understood.
Purpose of the Study:
- To investigate the effects of induced hyperthyroidism on brain function and oxidative stress markers in newborn rats.
- To assess the relationship between hyperthyroidism, brain metabolism, antioxidant enzyme activity, and survival.
Main Methods:
- Newborn Wistar rats were made hyperthyroid using tri-iodothyronine injections.
- Assays included survival, brain oxygen uptake, brain chemiluminescence, and antioxidant enzyme activity (superoxide dismutase, catalase, glutathione peroxidase).
- Brain chemiluminescence was measured directly and through parietal bones; oxygen uptake was measured in brain slices and mitochondria.
Main Results:
- Hyperthyroid rats exhibited increased spontaneous brain photoemission (46-70%) and a 30% increase in brain slice oxygen uptake.
- Lifespan was significantly reduced to approximately 16 weeks in hyperthyroid rats.
- Activities of superoxide dismutase, catalase, and Se-dependent glutathione peroxidase were elevated by 18-36% in hyperthyroid rat brains.
Conclusions:
- Induced hyperthyroidism causes increased brain metabolism and oxidative stress in newborn rats.
- Elevated oxygen and peroxyl radicals likely contribute to the observed premature aging phenotype.
- The findings highlight the detrimental effects of hyperthyroidism on brain health and longevity.