Acetylation is essential for nuclear heme oxygenase-1-enhanced tumor growth and invasiveness.

Overexpression of heme oxygenase-1 (HO-1), an endoplasmic reticulum-anchored enzyme, is observed in many cancers. HO-1 nuclear translocation has been shown to correlate with progression of several cancers. We recently reported that HO-1 is susceptible to intramembrane proteolysis and translocates to the nucleus to promote cancer growth and invasiveness without depending on its enzymatic activity. In the present study, we show that the HO-1 lacking C-terminal transmembrane segment (t-HO-1) was susceptible to acetylation by p300 and CREB-binding protein (CBP) histone acetyltransferase in the nucleus. Mass spectrometry analysis of HO-1 isolated from human embryonic kidney cells 293T (HEK293T) cells overexpressing CBP and t-HO-1 revealed two acetylation sites located at K243 and K256. Mutation of both lysine residues to arginine (R) abolished t-HO-1-enhanced tumor cell growth, migration and invasion. However, mutation of the lysine residues to glutamine (Q), a mimic of acetylated lysine, had no significant effect on t-HO-1-mediated tumorigenicity. Mechanistic studies demonstrated that transcriptional factor JunD interacted with wild-type (WT) t-HO-1 and mutant carrying K243/256Q but not K243/256 R mutation. Moreover, JunD-induced AP-1 transcriptional activity was significantly enhanced by coexpression with WT and acetylation-mimic but not acetylation-defective t-HO-1. Consistent with the in vitro observations, the implication of K243/256 acetylation in t-HO-1-enhanced tumorigenicity was also demonstrated in xenograft models. Immunohistochemistry performed with a specific antibody against acetyl-HO-1 showed the positive acetyl-HO-1 nuclear staining in human lung cancer tissues but not in the corresponding non-tumor tissues, supporting its clinical significance. Collectively, our findings highlight the importance of nuclear HO-1 post-translational modification in the induction of cancer progression.

γ-Synuclein Expression Is a Malignant Index in Oral Squamous Cell Carcinoma.

Dysregulation of γ-synuclein (SNCG) has been reported in many cancers; however, its role in cancer development is still controversial. Here, we examined the potential involvement of DNA methylation in regulating SNCG and its role in oral squamous cell carcinoma (OSCC). We used 8 OSCC cell lines to investigate SNCG methylation and expression. SNCG methylation was examination by methylation-specific polymerase chain reaction and bisulfate sequencing. Cells showing a high degree of SNCG methylation were treated with 5-aza (methylation inhibitor), and changes in their methylation and expression profiles were analyzed. Functional effects of SNCG in OSCC were examined by its overexpression and knockdown. Additionally, methylation and expression of SNCG in OSCC tissues were investigated and correlated with clinicopathologic features. All OSCC cells showed detectable SNCG expression at the mRNA and protein levels. Methylation-specific polymerase chain reaction and bisulfate sequencing revealed high SNCG expression in SCC25 cells with the unmethylated allele, and their 15 CpG islands were unmethylated. The methylated allele was detected only in OEC-M1 cells exhibiting low SNCG expression, and their CpG islands were partially methylated. 5-aza treatment in OEC-M1 cells attenuated methylation and restored SNCG expression. SNCG overexpression increased colony forming, migration, and invasion abilities in OEC-M1 cells. Silencing SNCG in SCC25 cells suppressed these behaviors. All 25 tumor-adjacent normal tissues were negative for SNCG immunostaining. SNCG upregulation was frequently observed in dysplastic and OSCC tissues. Positive SNCG expression was found in 45% (37 of 82) OSCC tissues. Positive SNCG expression in OSCC significantly correlated with cancer staging and lymph node metastasis. However, SNCG methylation did not correlate with its expression and clinicopathologic variables in OSCC tissues. DNA methylation may participate in regulating SNCG expression in some OSCC cells. SNCG upregulation could be involved in OSCC progression.

Signal peptide peptidase-mediated nuclear localization of heme oxygenase-1 promotes cancer cell proliferation and invasion independent of its enzymatic activity.

Heme oxygenase-1 (HO-1) is a heme-degrading enzyme anchored in the endoplasmic reticulum by a carboxyl-terminal transmembrane segment (TMS). HO-1 is highly expressed in various cancers and its nuclear localization is associated with the progression of some cancers. Nevertheless, the mechanism underlying HO-1 nuclear translocation and its pathological significance remain elusive. Here we show that the signal peptide peptidase (SPP) catalyzes the intramembrane cleavage of HO-1. Coexpression of HO-1 with wild-type SPP, but not a dominant-negative SPP, promoted the nuclear localization of HO-1 in cells. Mass spectrometry analysis of cytosolic HO-1 isolated from HeLa cells overexpressing HO-1 and SPP revealed two adjacent intramembrane cleavage sites located after S275 and F276 within the TMS. Mutations of S275F276 to A275L276 significantly hindered SPP-mediated HO-1 cleavage and nuclear localization. Nuclear HO-1 was detected in A549 and DU145 cancer cell lines expressing high levels of endogenous HO-1 and SPP. SPP knockdown or inhibition significantly reduced nuclear HO-1 localization in A549 and DU145 cells. The positive nuclear HO-1 stain was also evident in lung cancer tissues expressing high levels of HO-1 and SPP. Overexpression of a truncated HO-1 (t-HO-1) lacking the TMS in HeLa and H1299 cells promoted cell proliferation and migration/invasion. The effect of t-HO-1 was not affected by a mutation in the catalytic site. However, blockade of t-HO-1 nuclear localization abolished t-HO-1-mediated effect. The tumorigenic effect of t-HO-1 was also demonstrated in the mouse model. These findings disclose that SPP-mediated intramembrane cleavage of HO-1 promotes HO-1 nuclear localization and cancer progression independent of HO-1 enzymatic activity.

The effect of adlay oil on plasma lipids, insulin and leptin in rat.

This study was designed to investigate the effect of dietary adlay oil on plasma lipids, insulin and lipid peroxidation levels in rats. Twenty-four male Wistar rats fed diet containing adlay oil and cholesterol were studied for 4 weeks. The animals were divided into three groups: (1) 10% lard (control) group; (2) 5% lard + 5% adlay oil (5% adlay oil) group; and (3) 10% adlay oil group. Although there was no significant difference in body weight at the end of the feeding study, rats fed a diet containing adlay oil showed a significant decrease in adipose tissue weight and relative adipose weight. In addition, the rats fed the adlay oil showed significantly decreased low-density lipoprotein cholesterol (LDL-C), insulin, leptin and thiobarbituric acid reactive substance (TBARS) concentrations after 4 weeks of the feeding study. Although a significant decrease in total plasma cholesterol was observed in rats fed the 5% adlay oil diet, no significant difference was observed between the 10% adlay oil and control groups, and neither was a significant difference in liver TBARS concentration found between the dietary groups. Results from this study suggest that dietary adlay oil can reduce leptin, adipose tissue and LDL-C levels in rats.

The effect of high-fat and high-fructose diets on glucose tolerance and plasma lipid and leptin levels in rats.

AIM: High-fat and high-fructose diets are usually used to induce animal model diabetes mellitus. The purposes of this research were to compare the abnormalities of glucose metabolism caused by high-fructose diet and a high-fat diet and the effects of the high-fructose diet and high-fat diet on plasma leptin. METHODS: In this research, 24 Sprague-Dawley rats were used as the experimental animals, which were divided into three groups: chow diet (control group), high-fructose diet (60% fructose w/w) and high-fat diet (20% lard w/w). They were fed for a period of 8 weeks, during which an oral glucose tolerance test was conducted in the seventh week, and after completion of the eighth week, the abdominal adipose tissue and liver of the rats were excised and weighed, and the plasma cholesterol, triglyceride, insulin and leptin concentrations were assayed. RESULTS: The high-fat diet group presented a fasting blood glucose concentration that was higher than that of the control group. Furthermore, after 2 h of glucose challenge, the rats in the high-fat and high-fructose diet groups all presented higher plasma glucose concentrations than did the control group. The high-fat diet group showed higher body weight, higher relative liver weight, a higher plasma cholesterol concentration and higher amylase activity than did the other groups, whereas the high-fructose diet group showed higher fasting insulin and triglyceride concentrations. As for adipose tissue, the high-fat diet group presented an amount that was higher than that of the high-fructose and control groups, but the plasma leptin concentration of the high-fructose group was higher than that of the control group. CONCLUSIONS: It can be concluded from the above-mentioned experimental results that a high-fructose diet can cause hyperinsulinaemia, while a high-fat diet can result in impaired pancreatic function of insulin secretion and glucose intolerance, indicating that high-fructose diet and a high-fat diet may exert divergent effects on glucose metabolism in rats.

Chiral analysis of baclofen by alpha-cyclodextrin-modified capillary electrophoresis and laser-induced fluorescence detection.

An enantioselective method for baclofen (4-amino-3-p-chlorophenylbutyric acid) based on capillary electrophoresis (CE) separation and laser-induced fluorescence (LIF) detection has been developed. Naphthalene-2,3-dicarboxaldehyde (NDA) was used for precolumn derivatization of the nonfluorescent drug. alpha-Cyclodextrin (alpha-CD) was included in the buffer as a chiral selector for the separation of NDA-labeled S-(+)- and R-(-)-baclofen. Optimal resolution and detection were obtained with an electrophoretic buffer of 50 mM sodium borate (pH 9.5) containing 7 mM alpha-CD and a He-Cd laser (lambda ex = 442 nm, lambda em = 500 nm). Combined with a simple cleanup procedure, this method can be applied to the analysis of baclofen enantiomers in human plasma. The relative standard deviation (RSD) values on peak areas of a plasma sample containing 1.0 microM racemic baclofen were 6.4 and 4.9% (n = 8) for the S-(+)- and R-(-)-enantiomer, respectively. The RSD value on migration times of both enantiomers was 0.5% (n = 8). Calibration graphs for S-(+)- and R-(-)-baclofen in plasma showed a good linearity (r > or = 0.999) in the concentration range of 0.1-2.0 microM. The limit of detection of baclofen in plasma was about 10 ng/mL.

Tris(2,2'-bipyridyl)ruthenium(III)-based electrochemiluminescence detector with indium/tin oxide working electrode for capillary electrophoresis.

A novel tris(2,2'-bipyridyl)ruthenium(III) [Ru(bpy)3(3+)]-based electrochemiluminescence (ECL) detector for capillary electrophoresis (CE) has been developed. The detector was of the wall-jet configuration and an indium/tin oxide (ITO)-coated glass plate was used as the working electrode for end-column detection. Potential control of the ITO electrode was provided using a DC battery, without decoupling the detector from the CE field. Electrochemical behavior of Ru(bpy)3(2+) at the ITO electrode was found to be analogous to that at a Pt electrode. In the presence of tertiary or some secondary amines, ECL emission due to reaction between in situ generated Ru(bpy)3(3+) and analytes can be observed at the ITO surface. With 15 mM sodium borate (pH 9.5) plus 1 mM Ru(bpy)3(2+) present in the detection cell and the ITO electrode biased at 1.5 V (vs. Pt wire reference), a detection limit of 1 microM proline with a theoretical plate number of 4000 was obtained using the developed CE-ECL detection system. The detector response was found to be analyte-dependent, e.g. tryptophan gives no response, and the response for histidine is about 13-fold lower than that of proline.

Effect of dietary chitosans with different viscosity on plasma lipids and lipid peroxidation in rats fed on a diet enriched with cholesterol.

To investigate the effect of dietary chitosan on lipid metabolism, male SD (Sprague-Dawley) rats were fed a cholesterol-enriched diet containing 5% cellulose (CE), 5% chitosan (CCS; high viscosity), or 5% chitosan (FCS; low viscosity) for 4 weeks. The two types of chitosan with a comparable degree of deacetylation had a different molecular weight and intrinsic viscosity. Significantly (p < 0.05) lower plasma total cholesterol, LDL-cholesterol and VLDL-cholesterol concentrations were observed in the rats fed on the chitosan diets. In addition, chitosan significantly increased the fecal cholesterol and triglyceride contents. Although no significant difference in body weight was found among the dietary groups, the rats fed on the chitosan diets had lower relative liver weight when compared with those fed on the cellulose diet. Both of the chitosan groups had significantly lower liver total lipid and total cholesterol contents compared to the cellulose group, although the FCS group was less effective. The plasma and liver thiobarbituric acid reactive substances (TBAR) values were similar in the CE and FCS groups, while the CCS group had increased liver TBAR values. Although a significant increase in liver glucose-6-phosphate dehydrogenase activity was observed in the CCS group, no significant change was found in the FCS group. The observed influence of chitosans with different viscosity on the plasma lipid level, liver lipids and lipid peroxidation suggests that, while the hypocholesterolemic action of chitosans with different viscosity was similar, changes in the liver lipids and liver peroxidation status depended on their molecular weight when the deacetylation degree was comparable.

Analysis of baclofen by capillary electrophoresis with laser-induced fluorescence detection.

A new analytical method for baclofen (4-amino-3-p-chlorophenylbutyric acid) based on capillary electrophoretic separation and laser-induced fluorescence detection has been developed. Naphthalene-2,3-dicarboxaldehyde was used for precolumn derivatization of the non-fluorescent drug. Optimal separation and detection were obtained with an electrophoretic buffer of 50 mM sodium borate (pH 9.5) and a He-Cd laser (excitation at 442 nm, emission at 500 nm). Linearity (r > or = 0.99) over three orders of magnitude was generally obtained and the concentration limit of detection was in the nanomolar level. Coupled with a simple cleanup procedure, the method was successfully applied to the analysis of baclofen in human plasma. Recovery of spiked baclofen in plasma was 98%. The relative standard deviation values on peak size and migration time were 7.9% and 0.4%, respectively. The limit of detection of baclofen in plasma was 10 ng/ml.

Effects of dehulled adlay on the culture count of some microbiota and their metabolism in the gastrointestinal tract of rats.

Experiments were conducted to study the effect of a dietary supplement of dehulled adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) on the culture counts of some important groups of intestinal bacteria and their metabolism in the gastrointestinal (GI) tract of Sprague-Dawley rats. Rats were divided into four groups, and each group was fed a diet containing different levels of dehulled adlay for 30 days as follows: 0% (control), 5%, 20%, and 40%. All animals fed with adlay had normal healthy intestinal walls and no pathogenic signs whatsoever. There were no significant differences in body weight gain or the cecal pH between different groups of rats. Both the 20% and 40% groups had lower culture counts of enterics in their feces than the 5% and control groups, whereas the culture counts of fecal lactic acid bacteria were higher in feces of rats fed with adlay than in the control group. Cecal total short-chain fatty acid (SCFA) content and fecal SCFA were significantly higher in the 20% and 40% groups than in the control and 5% groups. All the adlay-fed rats had a higher fecal butyric acid concentration than the control rats. It is concluded that adlay has a significant influence on the growth of intestinal bacteria, which may ultimately affect the physiology and other functions of GI tracts of rats.

Plasma lipoprotein cholesterol levels in rats fed a diet enriched in cholesterol and cholic acid.

To investigate the effects of dietary cholesterol and cholic acid on plasma cholesterol levels, rats fed a cholesterol-free diet or a diet enriched in cholesterol (0.5% or 1%) with or without cholic acid supplementation were studied for 4 weeks. Although 0.5% cholesterol supplementation showed no effect on plasma total cholesterol and LDL-cholesterol levels in rats fed a diet without cholic acid treatment, the addition of dietary cholic acid caused an increase in plasma total cholesterol, LDL-cholesterol and VLDL-cholesterol levels in rats fed a cholesterol-rich diet. There was no significant change in HDL-cholesterol levels among the dietary groups. Rats fed a diet enriched in cholesterol have increased liver total lipids and total cholesterol contents. In addition, lower liver lipid peroxide concentration was found in rats fed a cholesterol-rich diet when compared with those fed the control diet. It is interesting that cholic acid supplementation led to an increase in hepatic cholesterol content and a decrease in liver lipid peroxide concentration in rats fed a cholesterol-rich diet. Results from this study suggest that dietary cholesterol and cholic acid might play an important role in regulation of lipid metabolism in rats.

[Lipids, lipoproteins and apolipoproteins in normal newborns]. / Lípidos, lipoproteínas y apolipoproteínas en recién nacidos normales.

BACKGROUND: In Chile, there is a high prevalence of cardiovascular diseases. Because atherosclerosis starts in childhood, it is important to assess serum lipid levels in children. AIM: To measure serum lipid levels in normal Chilean newborns. SUBJECTS AND METHODS: A sample of umbilical cord venous blood was obtained from 156 normal newborns (76 male) immediately after delivery. Total and HDL cholesterol, triglycerides, apoprotein A1, B and lipoprotein (a) were measured. RESULTS: Mean values for total cholesterol in males, females and in the total sample were 60.6, 67.8 and 64 mg/dl respectively. The figures for HDL cholesterol were 24.9, 29.3 and 27 mg/dl, for LDL cholesterol were 28.3, 32.4 and 30 mg/dl, for triglycerides were 37.5, 30.3 and 35 mg/dl, for apoprotein A1 were 69, 79 and 74 mg/dl, for apoB were 23, 25 and 24 mg/dl and for lipoprotein (a) were 1.58, 1.79 and 1.69 mg/dl. Total cholesterol, HDL cholesterol, triglycerides and apoprotein A1 were significantly different between sexes. Percentiles 5 and 95 for total cholesterol were 37 and 111, for HDL cholesterol were 14 and 40, for LDL cholesterol were 13 and 57, for triglycerides were 20 and 69, for apoprotein A1 were 53 and 101, for apoprotein B were 11 and 48 and for lipoprotein (a) were 1.3 and 2.1 mg/dl. Five percent of children had apoprotein B values over 48 mg/dl. CONCLUSIONS: The detection of high levels of apoprotein B in newborns, could allow the early identification of individuals with high cardiovascular risk.

Effect of dietary vitamin E on antioxidant status and antioxidant enzyme activities in Sprague-Dawley rats.

The effect of dietary vitamin E on plasma, red blood cells (RBC), hepatic antioxidant status, and antioxidant enzyme activities was investigated. Three groups of six Sprague-Dawley rats were fed 0, 100, or 1,500 ppm vitamin E for eight weeks. Plasma alpha-tocopherol level was increased significantly by increasing dietary vitamin E (p < 0.05). Plasma lipid peroxidation (thiobarbituric acid-reactive substances) stimulation by 1 mM t-butyl hydroperoxide was correlated with dietary vitamin E level and was significantly greater in rats fed no vitamin E than in rats fed 100 or 1,500 ppm vitamin E (p < 0.05). RBC reduced glutathione (GSH) level was positively correlated with dietary vitamin E and was significantly greater in rats fed 1,500 ppm vitamin E than in rats fed 0 or 100 ppm vitamin E (p < 0.05). RBC oxidized glutathione was negatively correlated with dietary vitamin E. GSH redox status was expressed as the GSH-to-total GSH ratio; the ratio was also positively correlated with dietary vitamin E and was significantly greater in rats fed 1,500 ppm vitamin E than in rats fed no vitamin E (p < 0.05). For antioxidant enzymes, superoxide dismutase activity in hepatic cytosolic fraction was significantly greater in rats fed 1,500 ppm vitamin E than in rats fed 100 ppm vitamin E. Hepatic GSH reductase activity was significantly greater in rats fed 100 ppm vitamin E than in rats fed no vitamin E (p < 0.05). Dietary vitamin E had no effect on plasma vitamin C and protein thiol levels. In the systems studied, results indicated that dietary vitamin E selectively influences plasma vitamin E level, RBC GSH status, and hepatic cytosolic superoxide dismutase and GSH reductase activities.

Effect of dietary fish oil on plasma lipoprotein cholesterol in rats fed a diet enriched in cholesterol and sucrose.

The aim of this study was to examine the effect of dietary fish oil on plasma lipoprotein cholesterol levels in rats fed different carbohydrate sources. Male Wistar rats fed a soy bean oil diet or a fish oil diet containing 0.5% cholesterol were studied for 7 weeks. Corn starch or sucrose were used as carbohydrate sources in the experimental diet. Fish oil supplementation significantly (p < 0.05) decreased plasma VLDL (very low density lipoprotein) cholesterol in rats fed a diet containing corn starch. However, there was no significant difference in plasma total cholesterol and LDL (low density lipoprotein) cholesterol in rats fed a corn starch diet with fish oil treatment. In the experiment with sucrose, significantly (p < 0.05) decreased plasma total cholesterol, LDL cholesterol and VLDL cholesterol were observed in rats fed a fish oil diet. Although higher plasma total and VLDL cholesterol levels were found in rats fed the sucrose diet when compared with those fed the corn starch diet, no significant difference between the corn starch group and the sucrose group was observed in rats after fish oil treatment. Results from the present study suggest that the carbohydrate source might play an important role in the regulation of plasma lipoprotein metabolism in rats fed fish oil.

[Serum lipid levels in children and teenagers from Concepción, Chile]. / Perfil lipídico y prevalencia de dislipidemias en niños y adolescentes de Concepción, Chile.

BACKGROUND: There is a relationship between serum lipid levels in children with those of adults. Preventive measures to reduce serum lipid levels should start in childhood. AIM: To study serum lipid levels in a representative sample of children and teenagers from Concepción, Chile. SUBJECTS AND METHODS: Serum total, HDL cholesterol and triglycerides were measured in 1,286 males and 816 females from 5 to 18 years old in the city of Concepción. RESULTS: Mean total cholesterol levels were 159 +/- 30 and 162 +/- 31 mg/dl in males and females respectively. The figures for HDL cholesterol were 46 +/- 11 and 47 +/- 11 mg/dl, for LDL cholesterol were 94 +/- 27 and 96 +/- 29 mg/dl and for triglycerides were 80 +/- 35 and 87 +/- 38 mg/dl. Nine percent of males and 12% of females had a total cholesterol over 200 mg/dl. Likewise 10% of males and 11% of females had a LDL cholesterol over 130 mg/dl. CONCLUSIONS: These numbers will help to plan and perform interventions in children, in order to prevent cardiovascular diseases.

[Lipoprotein in children and adolescents: relationship with family history of coronary artery disease]. / Lipoproteína en niños y adolescentes: relación con historia familiar de enfermedad coronaria.

BACKGROUND: Lipoprotein (a) is considered an independent cardiovascular risk factor. AIM: To study lipoprotein (a) levels in children of 18 years old or less with or without family history of coronary artery disease. SUBJECTS AND METHODS: Forty four children aged between 3 and 18 years old with a family history of coronary artery disease and 44 age and sex matched controls were studied. A fasting blood sample was obtained to measure total, HDL and LDL cholesterol, triglycerides, A1 and B apoproteins and lipoprotein (a). RESULTS: Compared to controls, children with a family history of coronary disease had higher total cholesterol (177 +/- 35 and 159 +/- 23 mg/dl respectively), LDL cholesterol (112 +/- 34 and 94 +/- 21 mg/dl respectively), triglycerides (89 +/- 38 and 71 +/- 25 mg/dl respectively), apoprotein B (85 +/- 17 and 65 +/- 13 mg/dl respectively) and lipoprotein (a) (40 +/- 50 and 22 +/- 31 mg/dl respectively). Thirty two percent of children with positive family history had lipoprotein (a) levels over 30 mg/dl, compared to 23% of controls. CONCLUSIONS: Children with family history of coronary artery disease have higher levels of cholesterol, triglycerides and lipoprotein (a) than matched controls.

Toxic effects of grass carp, snake and chicken bile juices in rats.

To evaluate the toxic effects of different animal bile juices, male Long-Evans rats were used and treated orally with different doses (0.03-0.6 ml) of grass carp, snake and chicken bile juices. After treating with one high dose (0.6 ml) for 6 and 24 h, the levels of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), alkaline phosphatase (ALP), blood urea nitrogen (BUN) and creatinine in the plasma of rats in the grass carp bile juice group became higher than those of the other two bile treated groups. After 3-days periodic treatment with 0.3 ml of each animal bile juice for 28 days, the levels of GOT, GPT, BUN and creatinine in the plasma of rats were significantly increased, especially the grass carp bile juice-treated rats. It appeared that the rats administered with snake and chicken bile juices for a much longer time were poisoned and had the same symptoms as those treated with grass carp bile juice.

Variation of plasma cholesterol levels in rats fed trans fatty acids or cis fatty acids.

To investigate the effect of dietary trans fatty acids on plasma and liver lipids, 16 Sprague Dawley male rats fed the hydrogenated soybean oil (Trans fat) or Cis fat from olive oil with two similar dietary fatty acid ratios for 9 weeks were studied. Higher plasma total cholesterol and LDL (low density lipoprotein) cholesterol levels were observed in rats fed trans fat diet when compared with rats fed the cis fat diet after 2 weeks of feeding. However, no significant changes in plasma total cholesterol and LDL cholesterol levels were found in rats of both dietary groups at 4-weeks of feeding. Rats fed trans fatty acids had lower plasma total cholesterol, LDL and VLDL (very low density lipoprotein) cholesterol levels at the end of the experimental period. Although significantly (p < 0.05) lower liver triacylglycerol contents were found in rats fed trans fat diet, no significant (p > 0.05) changes in liver cholesterol and phospholipids contents were observed in rats after trans fatty acids treatment. It is interesting that lower saturated to polyunsaturated ratios in fatty acid composition of plasma VLDL total lipids were found in rats fed trans fat diet. Results from this study suggest that the changes in plasma lipoprotein cholesterol in rats fed trans fatty acids might be related to the long or the short term study, and dietary trans fatty acids may alter the plasma lipoprotein metabolism in rats.