Maintaining low intracellular calcium is essential to the functioning of brain cells, yet the phenomenology and mechanisms involved remain an enigma. We have advanced a two-photon excitation time-resolved imaging technique, which exploits high sensitivity of the OGB-1 fluorescence lifetime to nanomolar Ca(2+) concentration ([Ca(2+)]) and enables a high data acquisition rate in situ. The [Ca(2+)...

0, in Table 1 ), since mitochondrial superoxide production increases linearly with 0, tension [XI . Whereas O2 had no effect on A q development at low Ca'+, A q dissipation at high Ca? + was markedly potentiated. Thus oxidative stress acted in strict synergism with Ca? + (as observed previously with hydroperoxides [ 5 ] ) . The adverse effects of Ca" and oxidative stress were abolished by 5 mM-...

Nitric oxide (NO) is a potent inhibitor of thrombin-induced increase in cytoplasmic free Ca concentration and aggregation in platelets, but the precise mechanism of this inhibition is unclear. To measure Ca/Mn influx in intact platelets and to monitor Ca uptake into the stores in permeabilized platelets, fura-2 was used. In intact platelets, maximal capacitative Ca and Mn influx developed rapid...

Since dental plaque reservoirs of fluoride (F), calcium (Ca) and inorganic phosphorus (Pi) are susceptible to decreases in pH, this in situ crossover study was conducted to test the hypothesis that the low concentration of these ions in plaque, formed in the presence of sucrose, could be attributed merely to the fermentation of this sugar. Eleven volunteers wore palatal appliances containing 6 ...