Calcium-binding of synaptosomes isolated from rat brain cortex. IV. Effects of ruthenium red on the Co-operative nature of calcium-binding.
Ruthenium red combines with isolated synaptosomes, resulting in strong inhibition of their Ca2+-binding. In isotonic saline media, however, the dye-induced inhibition of Ca2+-binding is significantly greater than that expected for the amount of bound dye and Hill's exponent of the Ca2+-binding decreases to 1 with an increase in the amount of the dye bound. On the other hand in isotonic mannitol-sucrose solution, inhibition of synaptosmal Ca2+-binding brought about by the dye is proportional to the amount of dye bound. Based on these results, the effects of the dye on the co-operative nature of synaptosomal Ca2+-binding is discussed.
D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008433:Mathematics; D051381:Rats; D012428:Ruthenium / Q000494:pharmacology*; D012430:Ruthenium Red / Q000494:pharmacology*; D013053:Spectrophotometry; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D012430:Ruthenium Red; D012428:Ruthenium; D002118:Calcium