AGE-DEPENDENT CHANGES IN VOLTAGE-GATED CALCIUM CHANNELS AND ATP-DEPENDENT POTASSIUM CHANNELS IN FISHER-344 RATS

1. Radioligand binding and Ca-45(2+) uptake measurements quantitated ion channel numbers and properties in brain membranes from Fisher 344 rats at 6, 12, 18 and 30 months of age. 2. Decreases in 1,4-dihydropyridine density occurred in striatum, hippocampus and cortex with a decreased affinity. 3. Decreases in w-conotoxin binding occurred in hippocampus and striatum with an increase in affinity. 4. K+ depolarization-mediated Ca-45(2+) uptake decreased only in striatum at 18 months. 5. Decreases in glibenclamide binding occurred in cortex and cerebellum at 12-30 months. 6. No changes in 1,4-dihydropyridine binding occurred with age in heart, but glibenclamide binding density was significantly decreased at 30 months.