TY - JOUR
T1 - Regulation of plasma leptin in mice
T2 - Influence of age, high-fat diet, and fasting
AU - Ahrén, Bo
AU - Månsson, Sven
AU - Gingerich, Ronald L.
AU - Havel, Peter J
PY - 1997/7
Y1 - 1997/7
N2 - Mechanisms regulating circulating leptin are incompletely understood. We developed a radioimmunoassay for mouse leptin to examine the influence of age, dietary fat content, and fasting on plasma concentrations of leptin in the background strain for the ob/ob mouse, the C57BL/6J mouse. Plasma leptin increased with age [5.3 ± 0.6 ng/ml at 2 mo (n = 23) vs. 14.2 ± 1.6 ng/ml at 11 mo (n = 15), P < 0.001]. Across all age groups (2-11 mo, n = 160), leg plasma leptin correlated with body weight (r = 0.68, P < 0.0001), plasma insulin (r = 0.38, P < 0.001), and amount of intra-abdominal fat (r = 0.90, P < 0.001), as revealed by magnetic resonance imaging. Plasma leptin was increased by a high-fat diet (58% fat for 10 mo) and reduced by fasting for 48 h. The reduction of plasma leptin was correlated with the reduction of plasma insulin (r = 0.43, P = 0.012) but not with the initial body weight or the change in body weight. Moreover, the reduction in plasma leptin by fasting was impaired by high-fat diet. Thus plasma leptin in C57BL/6J mice 1) increases with age or a high-fat diet; 2) correlates with body weight, fat content, and plasma insulin; and 3) is reduced during fasting by an action inhibited by high-fat diet and related to changes of plasma insulin.
AB - Mechanisms regulating circulating leptin are incompletely understood. We developed a radioimmunoassay for mouse leptin to examine the influence of age, dietary fat content, and fasting on plasma concentrations of leptin in the background strain for the ob/ob mouse, the C57BL/6J mouse. Plasma leptin increased with age [5.3 ± 0.6 ng/ml at 2 mo (n = 23) vs. 14.2 ± 1.6 ng/ml at 11 mo (n = 15), P < 0.001]. Across all age groups (2-11 mo, n = 160), leg plasma leptin correlated with body weight (r = 0.68, P < 0.0001), plasma insulin (r = 0.38, P < 0.001), and amount of intra-abdominal fat (r = 0.90, P < 0.001), as revealed by magnetic resonance imaging. Plasma leptin was increased by a high-fat diet (58% fat for 10 mo) and reduced by fasting for 48 h. The reduction of plasma leptin was correlated with the reduction of plasma insulin (r = 0.43, P = 0.012) but not with the initial body weight or the change in body weight. Moreover, the reduction in plasma leptin by fasting was impaired by high-fat diet. Thus plasma leptin in C57BL/6J mice 1) increases with age or a high-fat diet; 2) correlates with body weight, fat content, and plasma insulin; and 3) is reduced during fasting by an action inhibited by high-fat diet and related to changes of plasma insulin.
KW - C57BL/6J
KW - Insulin
KW - ob gene
UR - http://www.scopus.com/inward/record.url?scp=0030873309&partnerID=8YFLogxK
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M3 - Article
C2 - 9249540
AN - SCOPUS:0030873309
VL - 273
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 1931-857X
IS - 1 42-1
ER -