Fig. 7. Typical 13C NMR spectrum of perchloric acid extracts of haemolymph from fifth-instar M. sexta larvae given a dietary choice for 48 h and administered [2-13C]pyruvate. (A) Spectrum in the region –5.0 p.p.m. to 210 p.p.m. showing enrichments for alanine, trehalose and C5 of glutamate and glutamine. (B) Partial spectrum in the region 14–96 p.p.m. showing 13C-enrichments for C2 and C3 of alanine and Glx. (C) Partial spectrum in the region 59–96 p.p.m. showing the selective 13C-enrichment in trehalose, as well as other metabolites, including glycerol and glycerol phosphate with the same or similar chemical shifts. Haemolymph was collected 3.5 h post-injection. The spectrum was generated from 4000 data acquisitions and is shown with 3 Hz line broadening. See text for explanation of the metabolic derivation of 13C-enrichments.
