Lipolytic stimulant

D.L. Brasaemle, D M. Levin, D.C. Ad-ler-Wailes, and C. Londos, The lipolytic stimulation of 3T3-L1 adipocytes promotes the translocation of cytosolic hormone-sensitive lipase to the surface of lipid storage droplets, Biochim. Biophys. 

H.A. Hirsch and O.M. Rosen, Lipolytic stimulation modulates the subcellular distribution of hormone-sensitive lipase in 3T3-L1 cells, J. Lipid Res., 1984, 25,... 

G.M. Clieeord, C. Londos, F.B. Kraemer, R.G. Vernon, and S.J. Yeaman, Translocation of hormone-sensitive lipase and perilipin upon lipolytic stimulation of rat adipocytes, J. Biol. Chem., 2000,... 

Otfier fiormones accelerate tfie release of free fatty acids from adipose tissue and raise tfie plasma free fatty acid concentration by increasing the rate of lipolysis of the triacylglycerol stores (Figure 25—8). These include epinephrine, norepinephrine, glucagon, adrenocorticotropic hormone (ACTH), a- and P-melanocyte-stimulat-ing hormones (MSH), thyroid-stimulating hormone (TSH), growth hormone (GH), and vasopressin. Many of these activate the hormone-sensitive hpase. For an optimal effect, most of these lipolytic processes require the presence of glucocorticoids and thyroid hormones. These hormones act in a facilitatory or permissive capacity with respect to other lipolytic endocrine factors. 

Figure 25-8. Control of adipose tissue lipolysis. (TSH, thyroid-stimulating hormone FFA, free fatty acids.) Note the cascade sequence of reactions affording amplification at each step. The lipolytic stimulus is "switched off" by removal of the stimulating hormone the action of lipase phosphatase the inhibition of the lipase and adenylyl cyclase by high concentrations of FFA the inhibition of adenylyl cyclase by adenosine and the removal of cAMP by the action of phosphodiesterase. ACTFI,TSFI, and glucagon may not activate adenylyl cyclase in vivo, since the concentration of each hormone required in vitro is much higher than is found in the circulation. Positive ( ) and negative ( ) regulatory effects are represented by broken lines and substrate flow by solid lines.

In their study of untrained vs. trained swimmers, Collomp et al.40 suggested that specific training may be the catalyst that stimulates caffeine s ergogenic effects during high intensity, anaerobic activity. The results of many studies have also suggested that only well-trained athletes derive significant benefits from caffeine due to the athletes previously stimulated lipolytic activity and the increased size and density of their mito-chondria.40-52-58-59... 

Stimulation of protein synthesis in many tissues Mobilization of depot lipids from adipose tissue (lipolytic effect)... 

Hormones can modify the concentration of precursors, particularly the lipolytic hormones (growth hormone, glucagon, adrenaline) and cortisol. The lipolytic hormones stimulate lipolysis in adipose tissue so that they increase glycerol release and the glycerol is then available for gluconeogenesis. Cortisol increases protein degradation in muscle, which increases the release of amino acids (especially glutamine and alanine) from muscle (Chapter 18). 

Glucocorticoids not only break down protein but also stimulate the catabolism of lipids in adipose tissue and enhance the actions of other lipolytic agents. This occurrence results in an increase in plasma free fatty acids and an enhanced tendency to ketosis. The mechanism of this lipolytic action is unknown. The net effect of the biochemical changes induced by the glucocorticoids is antagonism of the actions of insulin. These biochemical events promote hyperglycemia and glycosuria, which are similar to the diabetic state. 

Clegg (1980) reported that bovine serum and high-density lipoprotein (HDL) caused an increase in free fatty acid levels in unpasteurized bulk milk. Lipoprotein free serum, apo HDL, all individual HDL tested, and the unfractionated C-peptide fractions had no lipolytic effect. HDL-lipid in the presence of 2 C-peptides and the combination of HDL-lipid with unfractionated C-peptide caused a considerable stimulation of lipolysis. 

Benefits The herb has stimulant effects due to the caffeine and chlorogenic acids. It is also diuretic and reportedly has lipolytic (fat-burning) effects. Folklore In South America, a tea brewed from the herb (also called mate ) is served on social occasions as a communal recreational beverage that is very stimulating. The mate is prepared in a bowl that is passed around the assembled people it is drank from the bowl by means of a silver straw with a strainer on the lower end to prevent the leaves being ingested (Bown, 2003 British Herbal Medicine Association, 1983 Graenwald et al., 2002). 

In fat cells epinephrine stimulation of cyclic AMP accumulation and lipolysis is markedly reduced in hypothyroidism but enhanced in hyperthyroidism (see Ref. 79). Similar effects of altered thyroid status on the response to two other lipolytic hormones, ACTH and glucagon, have been reported suggesting that thyroid hormones regulate similarly either the different receptors of the various lipolytic hormones and/or a common step of the lipolytic pathway [80],... 

Hall, B., Muller, D.P.R. 1982. Studies on the bile salt stimulated lipolytic activity of human milk using whole milk as source of both substrate and enzyme. I. Nutritional implications. 

There have been frequent difficulties relating physiological effects to cyclic AMP levels. For example, adenosine inhibits the effect of noradrenaline on cyclic AMP accumulation in rat fat cells but does not interfere with the lipolytic effect of the catecholamine [58]. Both ACTH and its o-nitrophenyl sulphenyl derivative stimulate corticosterone synthesis in isolated rat adrenal cells to the same maximal rate, but the analogue has a 30- to 100-fold smaller effect than ACTH on cyclic AMP accumulation [60]. 

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