Fig. 6.

All ¹³C labeled glucose isotopomers in aspirated urine from bladder 3 h after ¹³C tracer glucose load. Glucose ¹³C isotopomer fractions are shown as per cent of the total ¹³C enriched fraction in urine (Y axis, Σm_{n=C1,2,3,4,5,6}) in control (C) and valproic acid treated (VPA) animals (X axis). Control and VPA treated animals showed distorted ¹³C labeled glucose isotopomer fractions in urine indicating increased tracer disposal via urine (M6, [U-¹³C₆]-d-glucose tracer injected at time 0; average + SEM, n = 8; *P = 0.016) in VPA treated animals. The various isotopomers indicate: M1, pyruvate carboxylase activity (*P = 0.029); M2, pyruvate dehydrogenase activity and complete TCA cycle turnaround; M3, glucose generated from [U-¹³C₃]-dl-lactate and the Cori cycle; M4, non-oxidative pentose cycle; and M5, oxidative pentose cycle