Table 1.

Glutamate and glutamine isotopomer analysis

	Glutamate			Glutamine
	NSS	SS	NSS	SS
Fc2	0.227±0.030	0.227±0.021	0.656±0.079*	0.558±0.039*
Fc0	0.773±0.030	0.734±0.027	0.344±0.079*	0.405±0.031*
Fc1		0.030±0.020		0.031±0.015
Fc12		0.010±0.005		0.006±0.007
Y		0.080±0.039		0.658±0.075*

Results of non-steady-state (NSS) and steady-state (SS) isotopomer analysis of glutamate and glutamine listed as mean ± SD (n = 5). Fc2 represents the fraction of acetyl-CoA labeled in the carbon 2 (C2) position, predominantly from exogenous [2,4,6,8-¹³C₄]octanoate; Fc0 corresponds to the contribution of unlabeled acetyl-CoA from unlabeled endogenous substrates; Fc1 and Fc12 show the fraction of acetyl-CoA labeled in C1 and both C1 and C2, respectively; and Y depicts flux through anaplerotic pathways relative to TCA cycle flux. No differences were found between non-steady-state and steady-state values for either glutamate or glutamine

^*different from glutamate (p ≤ 0.01)