scholarly journals In vitro study of the effect of raloxifene on lipid metabolism compared with tamoxifen

2000 ◽  
Vol 143 (3) ◽  
pp. 427-430 ◽  
Author(s):  
Y Hozumi ◽  
M Kawano ◽  
VC Jordan

OBJECTIVE: Tamoxifen and raloxifene, selective estrogen receptor modulators, decrease serum concentrations of total cholesterol; however, the effect of these drugs on triglyceride metabolism is unclear. In the present study, we investigated the in vitro effect of raloxifene on lipid metabolism and compared it with that of tamoxifen. DESIGN AND METHODS: Intracellular concentrations of total cholesterol and triglyceride in HepG2 cells were measured by an enzymatic method after tamoxifen or raloxifene treatment with or without oleic acid and with or without very low density lipoprotein. RESULTS: Intracellular concentrations of total cholesterol and triglyceride without oleic acid or very low density lipoprotein were not significantly different after treatment with tamoxifen or raloxifene. In contrast, although raloxifene with oleic acid did not increase the intracellular concentrations of triglyceride, tamoxifen treatment in the presence of oleic acid or very low density lipoprotein significantly increased (P<0.05) the triglyceride concentrations. CONCLUSION: The present study suggests that raloxifene does not increase intracellular triglyceride in the presence of oleic acid or very low density lipoprotein, in contrast to tamoxifen. Therefore, raloxifene might be safer than tamoxifen for treating patients with unstable triglyceride levels or a history of hypertriglyceridemia.

2007 ◽  
Vol 35 (05) ◽  
pp. 735-741 ◽  
Author(s):  
Xiao-Ming Du ◽  
Ning-Yi Sun ◽  
Norihiro Furusho ◽  
Jun Hayashi ◽  
Yukihiro Shoyama

A clinical study was performed on the effect of in vitro cultured Anoectochilus formosanus HAYATA on lipid-metabolism. Sixty-six volunteers, including 36 healthy, 14 high-triglyceride-, 11 high-cholesterol- and 5 high-triglyceride- and high cholesterol- subjects, were administrated with A. formosanus (450 mg/day) for 6 months or 12 months. A. formosanus significantly decreased the concentrations of the serum levels of cholesterol, low density lipoprotein and very low density lipoprotein in all volunteers. The results of the present study suggested that A. formosanus might function as a liver activator resulting in improvement of lipid-metabolism.


2020 ◽  
Vol 20 (3) ◽  
pp. 1368-1381
Author(s):  
Tianbiao Zhou ◽  
Hongyan Li ◽  
Hongzhen Zhong ◽  
Zhiqing Zhong ◽  
Shujun Lin

Background and Objectives: Apolipoprotein E (apoE) plays a central role in the metabolism and homeostasis of lipids. ApoE gene encodes three major isoforms: ε2, ε3 and ε4 forming six phenotypes: Ε2Ε2, Ε2Ε3, Ε2Ε4, Ε3Ε3, Ε3Ε3 and Ε4Ε4 . Disorders of the lipid metabolism and the homeostasis are frequently coexist in renal diseases. The association be- tween gene polymorphisms of apoE and lipid metabolism were not consistent. This meta-analysis was performed to assess the association between gene polymorphisms of apoE and lipid metabolism in renal diseases. Methods: A pre-defined literatures search and selection of eligible relevant investigations were performed to extract and collect data from electronic databases. Results: Sixteen articles were enrolled for the analysis of association between apoE gene polymorphisms and lipid metab- olism. Subjects with E3E4 had a higher total cholesterol (TC) than those with E3E3, and subjects with E2E3 had a lower TC than those with E3E3. Subjects with ε2, ε3 had a lower TC than those with ε2, ε3 or ε4 , and subjects with ε4 had a higher TC than those with ε2, ε3 . Subjects with E2E2, E2E3 or E4E4 had a higher triglyceride (TG) than those with E3E3. Subjects with ε4 had a higher TG than those with ε2, ε3 . Subjects with ε2, ε3 had a higher level of TG than those with non-ε2, ε3 . Subjects with E3E4 had a slightly lower high-density lipoprotein (HDL) than those with E3E3. E3E4 appeared to be associated with lower levels of HDL. Subjects with E2E2, E2E3 had a notably lower low-density lipoprotein (LDL) than those with E3E3. Subjects with ε2, ε3 had a lower LDL than those with ε2, ε3 or ε4 ApoE gene polymorphisms were not associated with very low-density lipoprotein, and lipoprotein (a) [Lp(a)]. Subjects with E2E3 or E2E4 had higher apoE levels than those with E3E3, and subjects with E4E4 had lower apoE levels than those with E3E3. Conclusion: ApoE gene polymorphisms are associated with the expression of TC, TG HDL, LDL, Lp(a) or apoE. Keywords: Apolipoprotein E (ApoE) ; gene polymorphism; total cholesterol (TC) ;triglyceride (TG), high-density lipopro- tein (HDL); low-density lipoprotein (LDL); very low-density lipoprotein (VLDL); lipoprotein (a) [Lp(a)] • Meta-analysis


1982 ◽  
Vol 156 (1) ◽  
pp. 230-242 ◽  
Author(s):  
F C de Beer ◽  
A K Soutar ◽  
M L Baltz ◽  
I M Trayner ◽  
A Feinstein ◽  
...  

C-reactive protein (CRP), the classical acute-phase protein, can bind phospholipids by virtue of its specific, calcium-dependent reactivity with phosphorylcholine residues. However, analysis of acute-phase serum by gel filtration and by density gradient ultracentrifugation showed that the CRP was in a free, uncomplexed form, despite the coexistent presence of the various classes of serum lipoproteins, all of which contain phospholipids. In contrast, when isolated CRP was aggregated by immobilization at a sufficient density on a solid phase and then exposed to normal human serum, it selectively bound low density lipoprotein (LDL) and traces of very low density lipoprotein. The reaction was calcium dependent and reversible by free phosphorylcholine but not by heparin. LDL isolated from normal plasma was also bound by aggregated CRP. CRP reacts in vitro with a wide variety of different ligands both of extrinsic and of autogenous origin, e.g., microbial products and damaged cell membranes, respectively. If CRP aggregated in vivo by complexing with these ligands than acquires the capacity to selectively bind LDL, the phenomenon may have significant implications for the function of CRP and for the metabolism, clearance, and deposition of LDL.


2007 ◽  
Vol 79 (3) ◽  
pp. 254-258 ◽  
Author(s):  
Mariarosaria Napolitano ◽  
Alessandro Giuliani ◽  
Tonino Alonzi ◽  
Carmine Mancone ◽  
Gianpiero D'Offizi ◽  
...  

1996 ◽  
Vol 314 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Catherine S. BOURGEOIS ◽  
David WIGGINS ◽  
Geoffrey F. GIBBONS

Male Wistar rats were fitted with subcutaneous osmotic minipumps that delivered insulin at a constant rate of 0.20 i.u./h for 7 days. This treatment raised the plasma insulin concentration from 31±4 to 201±64 μ-i.u./ml. Hepatocytes prepared from the hyperinsulinaemic animals secreted very-low-density lipoprotein (VLDL) triacylglycerol (TAG) at a higher rate (172±21 μg per 24 h per mg cell protein) than did those from sham-operated controls (109±12 μg per 24 h per mg) (P < 0.05). However, chronic exogenous hyperinsulinaemia had no stimulatory effect on the secretion of VLDL apolipoprotein B (apoB) in derived hepatocytes compared with those from the sham-operated controls (2.32±0.38 compared with 3.09±0.40 μg per 24 h per mg). Hepatocytes from the hyperinsulinaemic rats thus secreted larger VLDL particles as evidenced by the increased TAG:apoB ratio (78.4±13.1 compared with 38.4±7.6; P < 0.05). In hepatocytes from the hyperinsulinaemic rats a larger proportion of the newly synthesized TAG was secreted as VLDL. Hepatocytes from the hyperinsulinaemic and the sham-operated control animals were equally sensitive to the inhibitory effect of insulin added in vitro on the secretion of VLDL TAG. Insulin added in vitro to the culture medium of hepatocytes from hyperinsulinaemic animals significantly decreased the TAG:apoB ratio of the secreted VLDL. This change did not occur in hepatocytes from sham-operated rats. These results suggest that, in vivo, chronic hyperinsulinaemia is not in itself sufficient to desensitize the liver to the acute inhibitory effect of insulin on the secretion of VLDL.


2001 ◽  
Vol 100 (5) ◽  
pp. 517-527 ◽  
Author(s):  
Jason M. R. GILL ◽  
Keith N. FRAYN ◽  
Stephen A. WOOTTON ◽  
George J. MILLER ◽  
Adrianne E. HARDMAN

Moderate exercise reduces postprandial triacylglycerol concentrations, which are a risk marker for coronary heart disease. The present study sought to determine the qualitative nature of exercise-induced changes in lipid metabolism and their association (if any) with changes in factor VII activation. Eleven normotriglyceridaemic men, aged 51.7±6.1 years (mean±S.D.), participated in two oral fat tolerance tests after different pre-conditions: control (no exercise), and exercise (90 min of brisk walking the day before). Venous blood samples were obtained in the fasted state and for 8 h after ingestion of a high-fat meal (1.32 g of fat, 1.36 g of carbohydrate, 0.30 g of protein and 10 mg of [1,1,1-13C] tripalmitin·kg-1 body mass). Prior exercise reduced postprandial plasma triacylglycerol concentrations by 25±3% (mean±S.E.M.), with lower concentrations in the Svedberg flotation rate (Sf) 20–400 (very-low-density lipoprotein) fraction accounting for 79±10% of this reduction. There was no effect on plasma factor VII coagulant activity or on the concentration of the active form of factor VIIa. Prior exercise increased postprandial serum 3-hydroxybutyrate and plasma fatty acid concentrations, decreased serum postprandial insulin concentrations and increased exogenous (8 h 13C breath excretion of 15.1±0.9% of ingested dose compared with 11.9±0.8%; P = 0.00001) and endogenous postprandial fat oxidation. These data raise the possibility that reduced hepatic secretion of very-low-density lipoprotein plays a role in the attenuation of plasma triacylglycerol concentrations seen after exercise, although it is possible that increased triacylglycerol clearance also contributes to this effect.


1990 ◽  
Vol 36 (9) ◽  
pp. 1673-1675 ◽  
Author(s):  
M González Estrada ◽  
C R Rodríguez Ferrer ◽  
I R Astarloa ◽  
E M Lahera

Abstract The values of low-density lipoprotein cholesterol obtained according to the Friedewald formula (Clin Chem 1972; 18:499-502), or by the De Long transformation (J Am Med Assoc 1986;256:2372-7), were compared with the values obtained when the individual cholesterol/triglyceride ratio of very-low-density lipoprotein was used for estimating the contribution of this lipoprotein to the total cholesterol. We found that these formulas gave the greatest errors for individuals with a low serum cholesterol/triglyceride ratio. We propose criteria for deciding when the numerically calculated value of low-density cholesterol is appropriate, and when it is not.


Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2169-2174 ◽  
Author(s):  
Wan Huang ◽  
Anantha Metlakunta ◽  
Nikolas Dedousis ◽  
Heidi K. Ortmeyer ◽  
Maja Stefanovic-Racic ◽  
...  

It is well established that leptin increases the sensitivity of carbohydrate metabolism to the effects of insulin. Leptin and insulin also have potent effects on lipid metabolism. However, the effects of leptin on the regulation of liver lipid metabolism by insulin have not been investigated. The current study addressed the effects of leptin on insulin-regulated hepatic very low-density lipoprotein (VLDL) metabolism in vivo in rats. A 90-min hyperinsulinemic/euglycemic clamp (4 mU/kg · min−1) reduced plasma VLDL triglyceride (TG) by about 50% (P &lt; 0.001 vs. saline control). Importantly, a leptin infusion (0.2 μg/kg · min−1) in combination with insulin reduced plasma VLDL-TG by about 80% (P &lt; 0.001 vs. insulin alone). These effects did not require altered skeletal muscle lipoprotein lipase activity but did include differential effects of insulin and leptin on liver apolipoprotein (apo) B and TG metabolism. Thus, insulin decreased liver and plasma apoB100/B48 levels (∼50%, P &lt; 0.01), increased liver TGs (∼20%, P &lt; 0.05), and had no effect on fatty acid oxidation. Conversely, leptin decreased liver TGs (∼50%, P &lt; 0.01) and increased fatty acid oxidation (∼50%, P &lt; 0.01) but had no effects on liver or plasma apoB levels. Importantly, the TG-depleting and prooxidative effects of leptin were maintained in the presence of insulin. We conclude that leptin additively increases the suppressive effects of insulin on hepatic and systemic VLDL metabolism by stimulating depletion of liver TGs and increasing oxidative metabolism. The net effect of the combined actions of insulin and leptin is to decrease the production and TG content of VLDL particles.


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