Decrease in Ca2+-ATPase activity in the brain plasma membrane of rats with increasing age: involvement of brain...

Area of Science:

• Neuroscience
• Biochemistry
• Gerontology

Background:

• Calcium homeostasis is crucial for brain function.
• Age-related changes in enzyme activity can impact cellular processes.
• Ca(2+)-ATPase plays a key role in regulating intracellular calcium levels.

Purpose of the Study:

• To investigate the effect of aging on Ca(2+)-ATPase activity in rat brain plasma membranes.
• To explore the role of thiol groups and signaling factors in age-related changes of Ca(2+)-ATPase.
• To understand the cellular mechanisms underlying age-associated calcium accumulation in the brain.

Main Methods:

• Measurement of Ca(2+)-ATPase activity in brain plasma membranes from young and aged rats.
• Assessment of the effects of thiol-modifying (N-ethylmaleimide) and protecting (dithiothreitol) reagents.
• Investigation of the influence of signaling molecules like dibutyryl cyclic AMP and inositol 1, 4, 5-trisphosphate.

Main Results:

• Aged rats exhibited significantly higher brain calcium content and reduced Ca(2+)-ATPase activity compared to young rats.
• Thiol (SH)-groups were identified as active sites of Ca(2+)-ATPase, unaffected by aging.
• The inhibitory effects of cyclic AMP and inositol trisphosphate on Ca(2+)-ATPase were diminished in aged rats, suggesting weakened signaling pathways.

Conclusions:

• Aging leads to a significant decrease in brain plasma membrane Ca(2+)-ATPase activity.
• The impaired enzyme activity contributes to calcium accumulation in the aging brain.
• Age-related decline in responsiveness to signaling factors may underlie altered calcium regulation.