Experimental protocols used to measure mitochondrial respiration. State 2 respiration was initiated by the addition of 5 mM glutamate and malate; state 3 respiration was initiated by the addition of 250 μM ADP. a Isoflurane (0.25 mM) was added in state 2 or state 3 after applying the complex I substrates glutamate and malate. b The NOS inhibitor L-NIO or the NO donor SNAP was added in state 1, 2, or 3 with or without isoflurane. CTL, control group; ISO, isoflurane; GM, glutamate and malate; Mito, mitochondria; ADP, adenosine diphosphate.