Adipose hormone-sensitive lipase preferentially releases polyunsaturated fatty acids from triglycerides

Lipids ◽  
1992 ◽  
Vol 27 (12) ◽  
pp. 950-954 ◽  
Author(s):  
Victor C. Gavino ◽  
Grace R. Gavino
1976 ◽  
Vol 230 (2) ◽  
pp. 385-388 ◽  
Author(s):  
JA McGarr ◽  
LB Oscai ◽  
J Borensztajn

Hormone-sensitive lipase activity was measured in adipocytes of rats subjected to a 12-wk program of treadmill running. Enzyme activity in the runners sacrificed immediately after exercise increased 2.5-fold (P less than 0.001) in tissue exposed to epinephrine and threefold (P less than 0.001) in tissue not exposed to epinephrine, when the results were expressed per gram of adipose tissue. Increases of almost the same magnitude were observed in runners sacrificed 24 h after their last bout of work. These significant increases in enzyme activity, however, were the result of a significant reduction in the size of cells in the epididymal fat pads of the exercisers compared with those of the freely eating sedentary animals (68.7 +/- 2.7 mum vs. 82.0 +/- 2.7 mum; P less than 0.01). When the results were expressed on a per-cell basis, therefore, hormone-sensitive lipase activity, assayed in the presence or absence of epinephrine, was unaffected by the exercise program. These results provide evidence that the lipolytic capacity of adipocytes of normal, untrained rats is sufficiently large to meet the increased demand for free fatty acids imposed by the exercise program without the need for an adaptive increase in enzyme activity.


2010 ◽  
Vol 77 (2) ◽  
pp. 190-198 ◽  
Author(s):  
Ali Zidi ◽  
Víctor M Fernández-Cabanás ◽  
Juan Carrizosa ◽  
Jordi Jordana ◽  
Baltasar Urrutia ◽  
...  

Hormone-sensitive lipase (LIPE) plays a fundamental role in the regulation of energy balance by releasing free fatty acids from adipose triacylglycerol stores. These fatty acids can be subsequently transferred to other body compartments to be oxidized or employed in other biochemical reactions. This enzymic function is particularly important in lactating animals because the synthesis of milk components involves the mobilization of lipid depots to satisfy the large energy demands of the mammary gland. In the current study, we partially sequenced the goat LIPE gene in several individuals. In doing so, we identified two synonymous polymorphisms at exons 2 (c.327C>A>T, triallelic polymorphism) and 3 (c.558C>T). Moreover, we found a mis-sense polymorphism at exon 6 (c.1162G>T) that involves an alanine to serine substitution at position 388. Analysis with Polyphen and Panther softwares revealed that this amino acid replacement is expected to be neutral. Performance of an association analysis with a variety of milk traits revealed that goat LIPE genotype has highly suggestive effects on milk yield (P=0·0032) as well as on C18:3 n-6g (P=0·0051), trans-10 cis-12 CLA (P=0·007) and C12:0 (P=0·0084) milk contents. These associations are concordant with the preference of LIPE to selectively mobilize medium-chain and unsaturated fatty acids.


PLoS ONE ◽  
2011 ◽  
Vol 6 (6) ◽  
pp. e21603 ◽  
Author(s):  
Céline Fernandez ◽  
Kai Schuhmann ◽  
Ronny Herzog ◽  
Barbara Fielding ◽  
Keith Frayn ◽  
...  

Author(s):  
G.M.K. Nijher ◽  
S.R. Bloom

Glucagonomas are neuroendocrine tumours arising from the α‎ cells of the islets of Langerhans, which result in excessive secretion of glucagon and peptides derived from preproglucagon. Post-translational modification of proglucagon is tissue specific and results in various glucagon peptides (1). It is the ratio of insulin to glucagon that controls the balance of gluconeogenesis and glycogenolysis in the liver. Glucagon stimulates hepatic gluconeogenesis and inhibits both glycolysis and glycogen synthesis. It increases production of free fatty acids from triglyceride breakdown by activating hormone-sensitive lipase; these undergo fatty oxidation in the liver via acetyl CoA, forming ketone bodies. The increase in free fatty acids from lipolysis inhibits hepatic lipogenesis. Glucagon also increases muscle proteolysis, resulting in an increase in amino acid supply to the liver.


2015 ◽  
Vol 93 (3) ◽  
pp. 262-267 ◽  
Author(s):  
Phillip M. Marvyn ◽  
Ryan M. Bradley ◽  
Emily B. Button ◽  
Emily B. Mardian ◽  
Robin E. Duncan

Circulating non-esterified fatty acids (NEFA) rise during fasting and are taken up by the kidneys, either directly from the plasma or during re-uptake of albumin from glomerular filtrate, and are stored as triacylglycerol (TAG). Subsequent utilization of stored fatty acids requires their hydrolytic release from cellular lipid droplets, but relatively little is known about renal lipolysis. We found that total [3H]triolein hydrolase activity of kidney lysates was significantly increased by 15% in the fasted state. Adipose triglyceride lipase (Atgl) and hormone-sensitive lipase (Hsl) mRNA expression was time-dependently increased by fasting, along with other fatty acid metabolism genes (Pparα, Cd36, and Aox). ATGL and HSL protein levels were also significantly induced (by 239 ± 7% and 322 ± 8%, respectively). Concomitant with changes in total protein levels, there was an increase in ATGL phosphorylation at the AMPK-regulated serine 406 site in the 14-3-3 binding motif, and an increase in HSL phosphorylation at serines 565 and 660 that are regulated by AMPK and PKA, respectively. Using immunofluorescence, we further demonstrate nearly ubiquitous expression of ATGL in the renal cortex with a concentration on the apical/lumenal surface of some cortical tubules. Our findings suggest a role for ATGL and HSL in kidney lipolysis.


Sign in / Sign up

Export Citation Format

Share Document