TY - JOUR
T1 - Insulin dose-response characteristics for suppression of glycerol release and conversion to glucose in humans
AU - Nurjhan, N.
AU - Campbell, P. J.
AU - Kennedy, F. P.
AU - Miles, J. M.
AU - Gerich, J. E.
PY - 1986
Y1 - 1986
N2 - To compare the dose-response characteristics for suppression of lipolysis and suppression of glucose production by insulin, 13 normal nonobese individuals were infused with insulin at rates of 0.1, 0.2, 0.4, 0.8, and 1.6 mU · kg-1 · min-1 while normoglycemia was maintained with the glucose clamp technique. Glucose appearance and glycerol appearance (taken as index of lipolysis) were measured isotopically with simultaneous infusions of 3-[3H]glucose and U-[14C]glycerol. Baseline glucose and glycerol rates of appearance were 14 ± 0.5 and 1.7 ± 0.2 μmol · kg-1 · min-1, respectively. Approximately 3% of plasma glucose originated from glycerol, and this accounted for ~ 50% of glycerol disposal. During the insulin infusions, arterial insulin (basal, 9.8 ± 0.6 μU/ml) increased to 14 ± 0.5, 20 ± 0.5, 31 ± 1, 58 ± 2, and 104 ± 6 μU/ml; calculated portal venous insulin (basal, 24 ± 2 μU/ml) increased to 26 ± 1, 32 ± 3, 70 ± 4, and 115 ± 6 μU/ml. The rate of glucose appearance was suppressed 100%, whereas the rate of appearance of glycerol was maximally suppressed only 85%. Nevertheless, the insulin concentration that produced half-maximal suppression of glucose appearance was twice as great as that required for half-maximal suppression of glycerol appearance (26 ± 2 vs. 13 ± 2 μU/ml, P < .001). Insulin decreased both the absolute rate of glycerol conversion to plasma glucose and the percent of glycerol disposal appearing in plasma glucose (both P < .001). These results indicate that in normal humans the suppression of lipolysis is more sensitive to insulin than is the suppression of hepatic glucose production and that in addition to reducing glycerol availability, insulin suppresses glycerol incorporation into plasma glucose by another (presumably hepatic) mechanism.
AB - To compare the dose-response characteristics for suppression of lipolysis and suppression of glucose production by insulin, 13 normal nonobese individuals were infused with insulin at rates of 0.1, 0.2, 0.4, 0.8, and 1.6 mU · kg-1 · min-1 while normoglycemia was maintained with the glucose clamp technique. Glucose appearance and glycerol appearance (taken as index of lipolysis) were measured isotopically with simultaneous infusions of 3-[3H]glucose and U-[14C]glycerol. Baseline glucose and glycerol rates of appearance were 14 ± 0.5 and 1.7 ± 0.2 μmol · kg-1 · min-1, respectively. Approximately 3% of plasma glucose originated from glycerol, and this accounted for ~ 50% of glycerol disposal. During the insulin infusions, arterial insulin (basal, 9.8 ± 0.6 μU/ml) increased to 14 ± 0.5, 20 ± 0.5, 31 ± 1, 58 ± 2, and 104 ± 6 μU/ml; calculated portal venous insulin (basal, 24 ± 2 μU/ml) increased to 26 ± 1, 32 ± 3, 70 ± 4, and 115 ± 6 μU/ml. The rate of glucose appearance was suppressed 100%, whereas the rate of appearance of glycerol was maximally suppressed only 85%. Nevertheless, the insulin concentration that produced half-maximal suppression of glucose appearance was twice as great as that required for half-maximal suppression of glycerol appearance (26 ± 2 vs. 13 ± 2 μU/ml, P < .001). Insulin decreased both the absolute rate of glycerol conversion to plasma glucose and the percent of glycerol disposal appearing in plasma glucose (both P < .001). These results indicate that in normal humans the suppression of lipolysis is more sensitive to insulin than is the suppression of hepatic glucose production and that in addition to reducing glycerol availability, insulin suppresses glycerol incorporation into plasma glucose by another (presumably hepatic) mechanism.
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U2 - 10.2337/diab.35.12.1326
DO - 10.2337/diab.35.12.1326
M3 - Article
C2 - 3533681
AN - SCOPUS:0023026312
SN - 0012-1797
VL - 35
SP - 1326
EP - 1331
JO - Diabetes
JF - Diabetes
IS - 12
ER -