Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men
This study examined the postprandial lipemia of two groups of men displaying similar age, body weight, and regional fat distribution, but characterized by either low (n = 11) or high (n = 15) α2-adrenergic sensitivity of subcutaneous abdominal adipocytes. In addition to fat cell lipolysis, adipose t...
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| Format: | Article |
| Language: | English |
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Elsevier
2000-09-01
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| Series: | Journal of Lipid Research |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520334489 |
| _version_ | 1818671505705271296 |
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| author | P. Imbeault C. Couillard A. Tremblay J-P. Després P. Mauriège |
| author_facet | P. Imbeault C. Couillard A. Tremblay J-P. Després P. Mauriège |
| author_sort | P. Imbeault |
| collection | DOAJ |
| description | This study examined the postprandial lipemia of two groups of men displaying similar age, body weight, and regional fat distribution, but characterized by either low (n = 11) or high (n = 15) α2-adrenergic sensitivity of subcutaneous abdominal adipocytes. In addition to fat cell lipolysis, adipose tissue lipoprotein lipase (AT-LPL) as well as postheparin plasma LPL activities were measured in the fasting state. Fasting AT-LPL and PH-LPL activities were similar in both groups. Maximal adipose cell lipolysis induced by isoproterenol (β-adrenergic agonist) as well as the β-adrenergic sensitivity did not differ between both groups of men. The selective α2-adrenergic agonist UK-14304 promoted a similar antilipolytic response in subcutaneous abdominal adipocytes from both groups. However, the α2-adrenergic sensitivity, defined as the dose of UK-14304 that produced half-maximal inhibition of lipolysis (IC50), was significantly different between groups (P < 0.0001). Men with low versus high subcutaneous abdominal fat cell α2-adrenergic sensitivity showed higher fasting TG levels. In the whole group, a positive relationship was observed between log-transformed IC50 UK-14304 values of subcutaneous adipocytes and fasting TG levels (r = 0.39, P < 0.05), suggesting that a low abdominal adipose cell α2-adrenergic sensitivity is associated with high TG levels. After the consumption of a high-fat meal, subjects with low subcutaneous abdominal adipose cell α2-adrenergic sensitivity showed higher TG levels in total, medium, and small triglyceride-rich lipoprotein (TRL) fractions at 0- to 6-h time points than men with high adipocyte α2-adrenergic sensitivity (P values ranging from 0.01 to 0.05). Stepwise regression analysis showed that the fasting TG concentration was the only variable retained as a significant predictor of the area under the curve of TG levels in total TRL fractions (73% of variance) among independent variables such as body weight, percent body fat, visceral and subcutaneous abdominal adipose tissue accumulation measured by CT, as well as subcutaneous abdominal fat cell α2-adrenoceptor sensitivity. Taken together, these results indicate that a reduced antilipolytic sensitivity of subcutaneous abdominal adipocytes to catecholamines may increase fasting TG levels, which in turn play a role in the etiology of an impaired postprandial TRL clearance in men. —Imbeault, P., C. Couillard, A. Tremblay, J-P. Després, and P. Mauriège. Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men. J. Lipid Res. 2000. 41: 1367–1375. |
| first_indexed | 2024-12-17T07:25:04Z |
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| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
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| publishDate | 2000-09-01 |
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| series | Journal of Lipid Research |
| spelling | doaj.art-c05f8cc1d1664abca41e2c0282f702642022-12-21T21:58:40ZengElsevierJournal of Lipid Research0022-22752000-09-0141913671375Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in menP. Imbeault0C. Couillard1A. Tremblay2J-P. Després3P. Mauriège4Physical Activity Sciences Laboratory, Department of Social and Preventive Medicine, Laval University, Québec, Canada G1K 7P4Lipid Research Center, CHUQ Medical Research Center, Québec, Canada G1V 4G2Physical Activity Sciences Laboratory, Department of Social and Preventive Medicine, Laval University, Québec, Canada G1K 7P4Lipid Research Center, CHUQ Medical Research Center, Québec, Canada G1V 4G2; Québec Heart Institute, Laval Hospital Research Center, Québec, Canada G1V 4G5Physical Activity Sciences Laboratory, Department of Social and Preventive Medicine, Laval University, Québec, Canada G1K 7P4; Lipid Research Center, CHUQ Medical Research Center, Québec, Canada G1V 4G2; To whom correspondence should be addressed.This study examined the postprandial lipemia of two groups of men displaying similar age, body weight, and regional fat distribution, but characterized by either low (n = 11) or high (n = 15) α2-adrenergic sensitivity of subcutaneous abdominal adipocytes. In addition to fat cell lipolysis, adipose tissue lipoprotein lipase (AT-LPL) as well as postheparin plasma LPL activities were measured in the fasting state. Fasting AT-LPL and PH-LPL activities were similar in both groups. Maximal adipose cell lipolysis induced by isoproterenol (β-adrenergic agonist) as well as the β-adrenergic sensitivity did not differ between both groups of men. The selective α2-adrenergic agonist UK-14304 promoted a similar antilipolytic response in subcutaneous abdominal adipocytes from both groups. However, the α2-adrenergic sensitivity, defined as the dose of UK-14304 that produced half-maximal inhibition of lipolysis (IC50), was significantly different between groups (P < 0.0001). Men with low versus high subcutaneous abdominal fat cell α2-adrenergic sensitivity showed higher fasting TG levels. In the whole group, a positive relationship was observed between log-transformed IC50 UK-14304 values of subcutaneous adipocytes and fasting TG levels (r = 0.39, P < 0.05), suggesting that a low abdominal adipose cell α2-adrenergic sensitivity is associated with high TG levels. After the consumption of a high-fat meal, subjects with low subcutaneous abdominal adipose cell α2-adrenergic sensitivity showed higher TG levels in total, medium, and small triglyceride-rich lipoprotein (TRL) fractions at 0- to 6-h time points than men with high adipocyte α2-adrenergic sensitivity (P values ranging from 0.01 to 0.05). Stepwise regression analysis showed that the fasting TG concentration was the only variable retained as a significant predictor of the area under the curve of TG levels in total TRL fractions (73% of variance) among independent variables such as body weight, percent body fat, visceral and subcutaneous abdominal adipose tissue accumulation measured by CT, as well as subcutaneous abdominal fat cell α2-adrenoceptor sensitivity. Taken together, these results indicate that a reduced antilipolytic sensitivity of subcutaneous abdominal adipocytes to catecholamines may increase fasting TG levels, which in turn play a role in the etiology of an impaired postprandial TRL clearance in men. —Imbeault, P., C. Couillard, A. Tremblay, J-P. Després, and P. Mauriège. Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men. J. Lipid Res. 2000. 41: 1367–1375.http://www.sciencedirect.com/science/article/pii/S0022227520334489adipose cell lipolysislipase activitiesregional fat distributionlipoproteins |
| spellingShingle | P. Imbeault C. Couillard A. Tremblay J-P. Després P. Mauriège Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men Journal of Lipid Research adipose cell lipolysis lipase activities regional fat distribution lipoproteins |
| title | Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men |
| title_full | Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men |
| title_fullStr | Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men |
| title_full_unstemmed | Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men |
| title_short | Reduced α2-adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men |
| title_sort | reduced α2 adrenergic sensitivity of subcutaneous abdominal adipocytes as a modulator of fasting and postprandial triglyceride levels in men |
| topic | adipose cell lipolysis lipase activities regional fat distribution lipoproteins |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520334489 |
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