TY - JOUR
T1 - Quantification of the glycolytic origin of plasma glycerol
T2 - Implications for the use of the rate of appearance of plasma glycerol as an index of lipolysis in vivo
AU - Nurjhan, N.
AU - Kennedy, F.
AU - Consoli, A.
AU - Martin, C.
AU - Miles, J.
AU - Gerich, J.
N1 - Funding Information:
From the Diabetes Section, Division of Endocrinology. Departments of Medicine and Physiology, University of Pittsburgh, School of Medicine; and the Endocrine Research Unit, Mayo Clinic, Rochester, MN. Supported in part by US Public Health Service Grant Nos. AM20411, RROOO56, and RROO585. Address reprint requests to John E. Gerich, MD, University of Pittsburgh, Clinical Research Center, 3488 Presbyterian-University Hospital. 230 Lothrop St, Pittsburgh, PA 15261. Q 1988 by Grune & Stratton, Inc. 0026-0495/88/3704-0014$03.00/0
PY - 1988/4
Y1 - 1988/4
N2 - To assess whether plasma glycerol could be directly derived from plasma glucose, nine postabsorptive dogs were infused with [U-14C] glucose and [2-3H] glycerol to measure the rates of appearance of plasma glucose and glycerol and the conversion of plasma glucose to glycerol before (basal) and after two hours of infusion of glucose (45 μmol/kg/min). Basally (plasma glucose 4.9 ± 0.2 mmol/L; plasma insulin 5.9 ± 0.2 μU/mL), rates of appearance of plasma glucose and glycerol were 20 ± 2 and 5.9 ± 1.3 μmol/kg/min, respectively, and 1.6 ± 0.6% of plasma glycerol was derived from plasma glucose. After glucose infusion (plasma glucose 9.1 ± 0.7 mmol/L; plasma insulin 21.1 ± 1.9 μU/mL), the rate of appearance of plasma glycerol decreased 80% to 1.1 ± 0.3 μmol/kg/min and the percent of plasma glycerol from glucose increased significantly to 6.9 ± 2.9. However, the absolute rate of conversion of glucose to glycerol did not change (0.09 ± 0.03 v 0.07 ± 0.03 μmol/kg/min). We conclude that even under conditions of stimulated glycolysis and inhibited lipolysis, only a small amount of plasma glycerol is derived from plasma glucose. Thus, rates of appearance of plasma glycerol can be used as a measure of rates of overall lipolysis in vivo.
AB - To assess whether plasma glycerol could be directly derived from plasma glucose, nine postabsorptive dogs were infused with [U-14C] glucose and [2-3H] glycerol to measure the rates of appearance of plasma glucose and glycerol and the conversion of plasma glucose to glycerol before (basal) and after two hours of infusion of glucose (45 μmol/kg/min). Basally (plasma glucose 4.9 ± 0.2 mmol/L; plasma insulin 5.9 ± 0.2 μU/mL), rates of appearance of plasma glucose and glycerol were 20 ± 2 and 5.9 ± 1.3 μmol/kg/min, respectively, and 1.6 ± 0.6% of plasma glycerol was derived from plasma glucose. After glucose infusion (plasma glucose 9.1 ± 0.7 mmol/L; plasma insulin 21.1 ± 1.9 μU/mL), the rate of appearance of plasma glycerol decreased 80% to 1.1 ± 0.3 μmol/kg/min and the percent of plasma glycerol from glucose increased significantly to 6.9 ± 2.9. However, the absolute rate of conversion of glucose to glycerol did not change (0.09 ± 0.03 v 0.07 ± 0.03 μmol/kg/min). We conclude that even under conditions of stimulated glycolysis and inhibited lipolysis, only a small amount of plasma glycerol is derived from plasma glucose. Thus, rates of appearance of plasma glycerol can be used as a measure of rates of overall lipolysis in vivo.
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U2 - 10.1016/0026-0495(88)90140-0
DO - 10.1016/0026-0495(88)90140-0
M3 - Article
C2 - 3357420
AN - SCOPUS:0023913508
SN - 0026-0495
VL - 37
SP - 386
EP - 389
JO - Metabolism
JF - Metabolism
IS - 4
ER -