The effect of nicotine on glycogen synthesis

The purpose of this study was to determine the effect of nicotine on glycogen synthesis. Following a 24 hour fast, female Sprague-Dawley rats were infused for 2 hours at 9-5 ul/rnin with 25% [1-13C] glucose. In addition, the infusate contained 1.1 rnM nicotine bitartrate for the nicotine treated animals(N) and no nicotine for the control group(C). After the infusion, the animal was anes(hetized, liver tissue was removed, freeze clamped and stored at -85C. NMR spectra indicate the glycogen was synthesized using a greater amount of direct pathway in N compared to C (52% vs 29%, P-0.012). Liver glycogen concentration was 23.2 mg/g for C and 10.8 mg/g for N (P<0.001). The effect of nicotine was to increase the use of the direct pathway, but decrease the amount of net glycogen synthesis. Results indicate that the natural pathway of glucose is modified by nicotine in such a way as to more directly convert it to glycogen before allowing it to be used by peripheral tissues.