Module 5: Figure cytosolic and mitochondrial Ca2+ transients
Relationship between cytosolic Ca2+ transients and mitochondrial metabolism in hepatocytes.
Cytosolic Ca2+ oscillations ([Ca2+]c), which were induced by phenylephrine, markedly enhanced mitochondrial metabolism, as monitored by measuring the level of NAD(P)H. The three cells depicted here had very different spike frequencies. Cell A had a low frequency and illustrates how a single spike resulted in a marked increase in NAD(P)H, which then recovered very much more slowly than the Ca2+ transient. In cells B and C, which were spiking at higher frequencies, the repetitive Ca2+ spikes occurred before recovery was complete, thus giving either a sawtooth profile (cell B) or a maintained elevation of mitochondrial metabolism (cell C). Reproduced from Biochim. Biophys. Acta, Vol. 1366, Robb-Gaspers, L.D., Rutter, G.A., Burnett, P., Hajnóczky, G., Denton, R.M. and Thomas, A.P. (1998) Coupling between cytosolic and mitochondrial calcium oscillations: role in the regulation of hepatic metabolism, pp. 17–32. Copyright (1998), with permission from Elsevier; see Robb-Gaspers et al. 1998.