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Marked Re-Utilization of Free Fatty Acids During Activated Lipolysis in Human Skeletal Muscle.

Enoksson, Staffan; Hagström-Toft, Eva; Nordahl, Joakim; Hultenby, Kjell; Pettersson, Nils; Isaksson, Bengt; Permert, Johan; Wibom, Rolf; Holm, Cecilia LU and Bolinder, Jan, et al. (2005) In Journal of Clinical Endocrinology and Metabolism 90(2). p.1189-1195
Abstract
Release of glycerol and free fatty acids (FFA) was investigated in human skeletal muscle strips. In the basal state, glycerol and FFA were released at almost equimolar rates (0.3 nmol/ng tissue.90 min). A nonselective beta-adrenoceptor agonist, isoprenaline, caused a concentration-dependent stimulation of glycerol release, whereas FFA release was unaffected. Basal and isoprenaline-induced glycerol release correlated positively with the age of the donors (r = 0.5, P < 0.005) but not with their body mass index (P > or = 0.4). Biochemical experiments with hormone-sensitive lipase (HSL) showed that most enzyme activity was both in the cytosol and mitochondrial fraction and that it constituted the common long and active form of the... (More)
Release of glycerol and free fatty acids (FFA) was investigated in human skeletal muscle strips. In the basal state, glycerol and FFA were released at almost equimolar rates (0.3 nmol/ng tissue.90 min). A nonselective beta-adrenoceptor agonist, isoprenaline, caused a concentration-dependent stimulation of glycerol release, whereas FFA release was unaffected. Basal and isoprenaline-induced glycerol release correlated positively with the age of the donors (r = 0.5, P < 0.005) but not with their body mass index (P > or = 0.4). Biochemical experiments with hormone-sensitive lipase (HSL) showed that most enzyme activity was both in the cytosol and mitochondrial fraction and that it constituted the common long and active form of the protein. Electron microscopy studies in rat skeletal muscle using labeled highly specific HSL antibodies verified the cytosolic location of HSL and, furthermore, indicated an accumulation of HSL-adjoining mitochondria. These results suggest that FFA produced in myocytes during catecholamine-induced lipolysis are retained by the muscle and, therefore by inference, reused. It is conceivable that efficient hydrolysis of acylglycerol by HSL located in the cytosol as well as near the mitochondria may facilitate mitochondrial FFA oxidation. In addition, muscle lipolysis activity increases during aging and may be independent of total body fat. (Less)
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Journal of Clinical Endocrinology and Metabolism
volume
90
issue
2
pages
1189 - 1195
publisher
The Endocrine Society
external identifiers
  • wos:000226850700086
  • pmid:15562022
  • scopus:20044366004
ISSN
1945-7197
DOI
10.1210/jc.2004-1079
language
English
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yes
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dc5e3c10-5ee9-4004-a87f-c3e6d87ea2c6 (old id 130672)
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http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15562022&dopt=Abstract
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2007-07-13 11:51:45
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@article{dc5e3c10-5ee9-4004-a87f-c3e6d87ea2c6,
  abstract     = {Release of glycerol and free fatty acids (FFA) was investigated in human skeletal muscle strips. In the basal state, glycerol and FFA were released at almost equimolar rates (0.3 nmol/ng tissue.90 min). A nonselective beta-adrenoceptor agonist, isoprenaline, caused a concentration-dependent stimulation of glycerol release, whereas FFA release was unaffected. Basal and isoprenaline-induced glycerol release correlated positively with the age of the donors (r = 0.5, P &lt; 0.005) but not with their body mass index (P &gt; or = 0.4). Biochemical experiments with hormone-sensitive lipase (HSL) showed that most enzyme activity was both in the cytosol and mitochondrial fraction and that it constituted the common long and active form of the protein. Electron microscopy studies in rat skeletal muscle using labeled highly specific HSL antibodies verified the cytosolic location of HSL and, furthermore, indicated an accumulation of HSL-adjoining mitochondria. These results suggest that FFA produced in myocytes during catecholamine-induced lipolysis are retained by the muscle and, therefore by inference, reused. It is conceivable that efficient hydrolysis of acylglycerol by HSL located in the cytosol as well as near the mitochondria may facilitate mitochondrial FFA oxidation. In addition, muscle lipolysis activity increases during aging and may be independent of total body fat.},
  author       = {Enoksson, Staffan and Hagström-Toft, Eva and Nordahl, Joakim and Hultenby, Kjell and Pettersson, Nils and Isaksson, Bengt and Permert, Johan and Wibom, Rolf and Holm, Cecilia and Bolinder, Jan and Arner, Peter},
  issn         = {1945-7197},
  language     = {eng},
  number       = {2},
  pages        = {1189--1195},
  publisher    = {The Endocrine Society},
  series       = {Journal of Clinical Endocrinology and Metabolism},
  title        = {Marked Re-Utilization of Free Fatty Acids During Activated Lipolysis in Human Skeletal Muscle.},
  url          = {http://dx.doi.org/10.1210/jc.2004-1079},
  volume       = {90},
  year         = {2005},
}