Figure 6. Blockade of islet respiration reverses the NAD(P)H lowering effect of a stimulated [Ca²⁺]_c rise.

Electron transfer in the respiratory chain was blocked during steady-state oscillations in 10 mm glucose by the addition of 50 nm rotenone (Rot; A) or 3 mm sodium azide (NaN₃; B) (indicated by light grey bars). Both compounds induced a significant rise in NAD(P)H fluorescence which increased further upon depolarization-stimulated Ca²⁺ entry (30 mm KCl; grey bars). Responses are representative of 19 of 20 islets from three mice (rotenone) and 19 islets from four mice (NaN₃). Note that the extended NAD(P)H scale, necessary to view the response to the inhibitors, somewhat obscures the oscillations in the presence of 10 mm glucose.