TY - JOUR
T1 - Insulin regulation of lipolysis in nondiabetic and IDDM subjects
AU - Jensen, M. D.
AU - Caruso, M.
AU - Heiling, V.
AU - Miles, J. M.
PY - 1989
Y1 - 1989
N2 - To determine whether insulin regulation of lipolysis is abnormal in subjects with poorly controlled insulin-dependent diabetes mellitus (IDDM), free-fatty acid flux ([1-14C]palmitate) was measured under conditions ranging from complete insulin withdrawal to hyperinsulinemia. Seven nondiabetic and seven IDDM subjects were studied with the pancreatic clamp technique to control plasma insulin, growth hormone, and glucagon concentrations at the desired levels. Preliminary studies were performed to validate the experimental design. The palmitate flux response to insulin withdrawal (2.5 ± 0.2 vs. 2.5 ± 0.2 μmol · kg-1 · min-1) and maximally antilipolytic insulin concentrations (0.17 ± 0.02 vs. 0.23 ± 0.03 μmol · kg-1 · min-1) were not different in nondiabetic and IDDM subjects, respectively. In contrast, IDDM subjects required significantly greater plasma free-insulin concentrations to result in equivalent suppression of palmitate flux compared with nondiabetic subjects. Lipolysis was found to be very sensitive to insulin in nondiabetic humans, with half-maximal suppression occurring at plasma free-insulin concentrations of ~12 pM (< 2 μU/ml). We conclude that adipose tissue lipolysis is normally exquisitely sensitive to insulin and that sensitivity, but not responsiveness to insulin, is impaired in poorly controlled IDDM.
AB - To determine whether insulin regulation of lipolysis is abnormal in subjects with poorly controlled insulin-dependent diabetes mellitus (IDDM), free-fatty acid flux ([1-14C]palmitate) was measured under conditions ranging from complete insulin withdrawal to hyperinsulinemia. Seven nondiabetic and seven IDDM subjects were studied with the pancreatic clamp technique to control plasma insulin, growth hormone, and glucagon concentrations at the desired levels. Preliminary studies were performed to validate the experimental design. The palmitate flux response to insulin withdrawal (2.5 ± 0.2 vs. 2.5 ± 0.2 μmol · kg-1 · min-1) and maximally antilipolytic insulin concentrations (0.17 ± 0.02 vs. 0.23 ± 0.03 μmol · kg-1 · min-1) were not different in nondiabetic and IDDM subjects, respectively. In contrast, IDDM subjects required significantly greater plasma free-insulin concentrations to result in equivalent suppression of palmitate flux compared with nondiabetic subjects. Lipolysis was found to be very sensitive to insulin in nondiabetic humans, with half-maximal suppression occurring at plasma free-insulin concentrations of ~12 pM (< 2 μU/ml). We conclude that adipose tissue lipolysis is normally exquisitely sensitive to insulin and that sensitivity, but not responsiveness to insulin, is impaired in poorly controlled IDDM.
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U2 - 10.2337/diab.38.12.1595
DO - 10.2337/diab.38.12.1595
M3 - Article
C2 - 2573554
AN - SCOPUS:0024341125
SN - 0012-1797
VL - 38
SP - 1595
EP - 1601
JO - Diabetes
JF - Diabetes
IS - 12
ER -