Glucosamine incorporation into rat cerebrum: effect of adrenalectomy, corticosterone, exercise, and training

Incorporation of D-[I-14C]glucosamine into various metabolic fractions was studied in an experiment designed to quantify the relative influence of physiological and behavioral factors. Different physiological states were established by sham operation (S), adrenalectomy (A), and adrenalectomy plus corticosterone replacement (H). Within each physiological condition the behavioral state was varied by swim-escape training (E), swimming exercise (X) or nonswimming controls (C). Adrenalectomy caused a generalized increase in label uptake by cerebral cortex and hippocampus, but precursor levels in the blood were elevated also, suggesting a systemic physiological effect. Behavioral state had no effect on overall uptake, but did influence the distribution of label between soluble and membrane-bound glycoproteins. These results indicate that D-[I-14C]glucosamine is an effective glycoprotein and ganglioside precursor in behavioral experiments, provided corrections for the influence of systemic physiological factors are made.