Human Brain Glycogen Metabolism During and After Hypoglycemia Export

@article{citeulike:5728084, abstract = {10.2337/db09-0226 We tested the hypotheses that human brain glycogen is mobilized during hypoglycemia and its content increases above normal levels (\^{a}€œsupercompensates\^{a}€) after hypoglycemia. We utilized in vivo C nuclear magnetic resonance spectroscopy in conjunction with intravenous infusions of [C]glucose in healthy volunteers to measure brain glycogen metabolism during and after euglycemic and hypoglycemic clamps. After an overnight intravenous infusion of 99\% enriched [1-C]glucose to prelabel glycogen, the rate of label wash-out from [1-C]glycogen was higher (0.12 \^{A}± 0.05 vs. 0.03 \^{A}± 0.06 \^{I}¼mol \^{A}· g \^{A}· h, means \^{A}± SD, < 0.02, = 5) during a 2-h hyperinsulinemic-hypoglycemic clamp (glucose concentration 57.2 \^{A}± 9.7 mg/dl) than during a hyperinsulinemic-euglycemic clamp (95.3 \^{A}± 3.3 mg/dl), indicating mobilization of glucose units from glycogen during moderate hypoglycemia. Five additional healthy volunteers received intravenous 25\^{a}€“50\% enriched [1-C]glucose over 22\^{a}€“54 h after undergoing hyperinsulinemic-euglycemic (glucose concentration 92.4 \^{A}± 2.3 mg/dl) and hyperinsulinemic-hypoglycemic (52.9 \^{A}± 4.8 mg/dl) clamps separated by at least 1 month. Levels of newly synthesized glycogen measured from 4 to 80 h were higher after hypoglycemia than after euglycemia ( \^{a}‰¤ 0.01 for each subject), indicating increased brain glycogen synthesis after moderate hypoglycemia. These data indicate that brain glycogen supports energy metabolism when glucose supply from the blood is inadequate and that its levels rebound to levels higher than normal after a single episode of moderate hypoglycemia in humans.}, author = {\~{A}–z, G\~{A}¼lin and Kumar, Anjali and Rao, Jyothi P. and Kodl, Christopher T. and Chow, Lisa and Eberly, Lynn E. and Seaquist, Elizabeth R.}, citeulike-article-id = {5728084}, citeulike-linkout-0 = {http://dx.doi.org/10.2337/db09-0226}, citeulike-linkout-1 = {http://diabetes.diabetesjournals.org/content/58/9/1978.abstract}, citeulike-linkout-2 = {http://diabetes.diabetesjournals.org/content/58/9/1978.full.pdf}, citeulike-linkout-3 = {http://view.ncbi.nlm.nih.gov/pubmed/19502412}, citeulike-linkout-4 = {http://www.hubmed.org/display.cgi?uids=19502412}, comment = {The brain carbo-loads}, doi = {10.2337/db09-0226}, journal = {Diabetes}, keywords = {brain, carbohydrate, glucose, glycogen, hypoglycemia, load}, month = {September}, number = {9}, pages = {1978--1985}, posted-at = {2009-09-06 21:19:01}, priority = {2}, title = {Human Brain Glycogen Metabolism During and After Hypoglycemia}, url = {http://dx.doi.org/10.2337/db09-0226}, volume = {58}, year = {2009} }

TY - JOUR ID - citeulike:5728084 L3 - citeulike-article-id:5728084 N2 - 10.2337/db09-0226 We tested the hypotheses that human brain glycogen is mobilized during hypoglycemia and its content increases above normal levels (“supercompensates”) after hypoglycemia. We utilized in vivo C nuclear magnetic resonance spectroscopy in conjunction with intravenous infusions of [C]glucose in healthy volunteers to measure brain glycogen metabolism during and after euglycemic and hypoglycemic clamps. After an overnight intravenous infusion of 99% enriched [1-C]glucose to prelabel glycogen, the rate of label wash-out from [1-C]glycogen was higher (0.12 ± 0.05 vs. 0.03 ± 0.06 μmol · g · h, means ± SD, < 0.02, = 5) during a 2-h hyperinsulinemic-hypoglycemic clamp (glucose concentration 57.2 ± 9.7 mg/dl) than during a hyperinsulinemic-euglycemic clamp (95.3 ± 3.3 mg/dl), indicating mobilization of glucose units from glycogen during moderate hypoglycemia. Five additional healthy volunteers received intravenous 25–50% enriched [1-C]glucose over 22–54 h after undergoing hyperinsulinemic-euglycemic (glucose concentration 92.4 ± 2.3 mg/dl) and hyperinsulinemic-hypoglycemic (52.9 ± 4.8 mg/dl) clamps separated by at least 1 month. Levels of newly synthesized glycogen measured from 4 to 80 h were higher after hypoglycemia than after euglycemia ( ≤ 0.01 for each subject), indicating increased brain glycogen synthesis after moderate hypoglycemia. These data indicate that brain glycogen supports energy metabolism when glucose supply from the blood is inadequate and that its levels rebound to levels higher than normal after a single episode of moderate hypoglycemia in humans. IS - 9 JF - Diabetes EP - 1985 TI - Human Brain Glycogen Metabolism During and After Hypoglycemia VL - 58 SP - 1978 KW - brain KW - carbohydrate KW - glucose KW - glycogen KW - hypoglycemia KW - load N1 - The brain carbo-loads AU - Öz, Gülin AU - Kumar, Anjali AU - Rao, Jyothi AU - Kodl, Christopher AU - Chow, Lisa AU - Eberly, Lynn AU - Seaquist, Elizabeth PY - 2009/09// UR - http://dx.doi.org/10.2337/db09-0226 ER -