The objective of this study was to clarify the clinical significance and usefulness of measuring percent body fat (PBF) when compared with body mass index (BMI) in the Japanese population. A total of 2,483 Japanese individuals (1,380 men and 1,103 women) who underwent a medical checkup from 1999-2002 were employed. PBF was determined using bioelectrical impedance analysis (BIA). Relationships of age, BMI and PBF with several metabolic parameters, including blood pressure, lipids and plasma glucose levels were assessed in both genders separately. In men, PBF was a stronger determinant of total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and triglycerides (TG) compared with age and BMI, whereas in women, age was the strongest determinant of TC and LDL-C. In both genders, BMI was the strongest determinant of serum HDL-C among age, PBF and BMI. Based on these data, we suggest that measuring PBF by BIA is superior to BMI for predicting TC, LDL-C and TG in Japanese men.
The agarose gel electrophoresis and differential staining system is an easy and quick method for analyzing the serum lipid composition of each lipoprotein fraction. It has been reported in adults that measured values obtained by this method strongly correlated with those obtained by ultracentrifugation. The aim of this study was to examine the clinical application of this method for children, in comparison with the ultracentrifugation method. The subjects were sixteen hyperlipidemic and twenty-five normolipidemic children, aged from two to eighteen years old. Cholesterol (C) and triglyceride (TG) levels were determined in serum very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL) fractions by both methods. Correlation coefficients between the two methods for cholesterol levels were 0.937 (HDL), 0.983 (LDL) and 0.837 (VLDL), and for triglyceride levels were 0.735 (HDL), 0.621 (LDL) and 0.964 (VLDL). We confirmed the clinical application of this method to evaluate the lipoprotein lipid profile in children as well as in adults.
Ischemia/reperfusion (I/R) in post-arterior post-capillary venules induces an acute inflammatory response, characterized by increased adherence and emigration of leukocytes and vascular permeability, all of which play important roles in cardiovascular disease. The aim of this study was to determine the roles of angiotensin II and AT&sub1; receptor blockade in microvascular I/R injury in rats. Rats were anesthetized and intubated, then the peritoneum was opened and the mesentery was revailed. Small post-capillary venules were examined by in vivo fluorescence microscopy. The flow of erythrocytes and leukocytes was observed under the microscope and video recorded for later dynamic analyses. The superior mesenteric artery (SMA) was ligated with polyethylene tubing and released to induce I/R (20 min of ischemia/60 min of reperfusion). Subsequently, leukocyte adhesion, emigration and albumin leakage were compared with those of non-I/R controls. I/R injury was significantly suppressed by superfusing tissues with the AT&sub1; receptor antagonist losartan (LO; 10μM). The beneficial effects of LO were inhibited by topical application of either the bradykinin B&sub2; receptor antagonist HOE140 (10 nM) or nitric oxide (NO) synthase inhibitor Nω-nitro-L-arginine methyl ester (L-NAME 10μM). The effects of LO were lost in the presence of AT&sub2; receptor blocker PD 123319 (PD). In conclusion, LO suppressed and protected against I/R injuries. The possible interaction between AT&sub1; and AT&sub2; receptors was also suggested.
To clarify the pharmacological mechanism of ezetimibe, SCH 58053, an analog of ezetimibe, was intraduodenally administered to lymph-fistula rats, and its effect on lymphatic lipid transport in the intestine was monitored. SCH 58053, 5.0 mg/kg body weight, was administered one hour before a 5-hour infusion of a lipid emulsion containing 40μmol/h of triolein and 2.74μmol/h of cholesterol (Experiment 1) or co-administered at 5.0 mg/kg body weight/h with the lipid emulsion for 4 hours to rats that had been infused with the lipid emulsion alone for 3 hours (Experiment 2). SCH 58053 administration significantly inhibited lymphatic cholesterol transport, but not triglyceride transport, in both groups compared to control rats that did not receive SCH 58053. The ratio of free cholesterol to total cholesterol in the lymph of the treated rats was unchanged compared to the control rats. Thus, the results showed that SCH 58053 is a potent, rapid, and selective inhibitor of lymphatic cholesterol transport in the intestine.
Soy protein isolate (SPI) is known to reduce the risk of heart disease by lowering serum cholesterol and triacylglycerol (TG) levels. Soybean β-conglycinin, which is a component of SPI, might be the active ingredient that prevents and/or ameliorates lifestyle-related diseases, such as hyperlipidemia and obesity. This study aimed to determine the efficacy of soybean β-conglycinin for lowering the human serum TG level and visceral fat. Randomized double-blind placebo-controlled designs were used to test the effect of dietary β-conglycinin, which was taken in the form of candy. [Test 1]In order to examine the serum TG level, 138 volunteers aged 26 to 69 years with TG concentrations above 1.69 mmol/L participated in the study. The subjects were divided at random into two different groups: the test group only consumed the experimental candy containing β-conglycinin and the placebo group only consumed the placebo candy containing casein. The test period consisted of a 2-wk pre-evaluation phase to screen the participants, a 12-wk consumption period and a 4-wk post-evaluation phase. The serum TG concentrations were significantly reduced in the test group, compared with the placebo group, after consuming the experimental candy. [Test 2]In order to measure visceral fat by means of CT scanning, 102 volunteers aged 26 to 69 years with body mass indices (BMI) between 25 and 30 participated in the study. The subjects were divided at random into two different groups as for Test 1. The test period consisted of a 2-wk pre-evaluation phase to screen the participants, a 20-wk consumption period and a 4-wk post-evaluation phase. A significant reduction in visceral fat only occurred in the β-conglycinin group. This study showed that β-conglycinin is an effective food ingredient that will be of use to reduce high serum TG concentrations and to prevent obesity.
To clarify whether lipids deposited in human atheromatous lesions induce apoptosis of vascular smooth muscle cells (SMC) and to identify the main component in deposited lipids responsible for inducing apoptosis, we examined the effect of lipids extracted from human atheromatous lesions on apoptosis of cultured SMC and analyzed the content of cholesterol in the lipids. When lipids extracted from atheromatous lesions were added to SMC, agarose electrophoresis of DNA showed a ladder pattern, DNA fragmentation assay detected an increase of fragmented DNA, and flow cytometric analysis demonstrated an increase of apoptotic cells. When the extracted lipids were fractionated by Sep-Pak ODS column, addition of the oxysterol-rich fraction to SMC resulted in a DNA ladder pattern and positive staining of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL). The oxysterol-rich fraction also increased fragmented DNA and apoptotic cells to a greater extent than the other two fractions. HPLC analysis showed that the quantity of 7-ketocholesterol in extracted lipids was large enough to induce SMC apoptosis. These results suggest that lipids deposited in human atheromatous lesions may induce apoptosis of SMC and that oxysterols may be important factor contributing to induce apoptosis among deposited lipids.