Effect of the peroxisome proliferator perfluorodecanoic acid on growth and lipid metabolism in Sprague Dawley rats fed three dietary levels of selenium

The possible interrelationships between the effects of dietary selenium and perfluorodecanoic acid (PFDA) on growth and lipid metabolism were studied in the male Sprague Dawley rat. Rats were divided into groups and placed on diets containing three levels of selenium (0.04, 0.2, and 1.0 ppm as sodium selenite). Two weeks later, half the rats in each group received a single 35 mg/kg IP injection of PFDA in corn oil, while their pair-fed companion received only vehicle. Rats injected with PFDA stopped gaining weight, and weighed less than pair-fed controls, despite equal food intakes. Two weeks following PFDA administration the rats were killed and plasma cholesterol and triglycerides, and liver peroxisomal enzyme activities were quantified. In contrast to other peroxisome proliferators, PFDA increased plasma triglycerides while decreasing plasma cholesterol. The rate of peroxisomal fatty acid -oxidation was decreased, even though the activity of fatty acyl-CoA oxidase, the first enzyme in the peroxisomal fatty acid -oxidation pathway, was increased. Dietary selenium, other than increasing the liver to body weight ratio, did not alter growth or lipid metabolism. This study demonstrates, for the first time, the existence of a non-hypotriglyceridemic peroxisome proliferator-PFDA.     

Beta-oxidation of 1-[14C]-17-[131I]-iodoheptadecanoic acid following intracoronary injection in humans results in similar release of both tracers

Radioiodine labelled 17-iodo-heptadecanoic acid (IHA) is used for non-invasive study of myocardial metabolism in coronary heart disease and cardiomyopathy. Yet in the interpretation of in vivo myocardial tracer kinetics, it is controversial whether the intracellular degradation of IHA or the removal of iodide across cellular membranes is the rate-limiting step in iodide release from the myocardium. In five patients undergoing coronary sinus catheterization, a mixture of about 40 kBq of [¹²³I] NaI was injected into the left coronary artery. During the following 15-min period, frequent blood samples were taken from the aorta and the coronary sinus. In the aqueous phase of the venous blood, ¹⁴CO₂ and inorganic ¹³¹I appeared nearly in parallel, with a peak time of 4–5 min. Moreover, as shown by the AV difference, there was no significant back diffusion of IHA and no significant non-specific deiodination detectable over the period of observation. There was myocardial retention of inorganic iodide (¹²³I) injected into the left coronary artery. The data strongly support the premise that lipid turnover through -oxidation is the rate-limiting step in the externally measured release of iodide after IHA injection, provided that recirculating inorganic radioactive iodide is corrected for. In addition, 15 volunteers were studied using [¹¹C]palmitic acid and [¹²³I]IHA using PET and dynamic planar camera scintigraphy with iodide correction. There was no significant difference between the mean values of the elimination half-times, and also no significant correlation between half-times of both fatty acids for single individuals.     

Swimming capacity of mice after prolonged treatment with psychostimulants

Swimming endurance and availability of metabolic substrates (blood glucose and nonesterified fatty acids [NEFA], liver and muscle glycogen, body fat) were studied in mice treated with 10 g/g methamphetamine/day for 6 weeks. At the end of the 6-week treatment, motor coordination of the methamphetamine-treated animals was much better than that of controls, and swimming capacity tended to increase. While swimming, mice treated with methamphetamine mobilized more glycogen from the hepatic stores and utilized glucose more effectively. Their NEFA levels in blood were higher than those of controls. There was no difference in the muscular glycogen content.     

Swimming capacity of mice after prolonged treatment with psychostimulants

The effect of long-term treatment with fencamfamine on swimming endurance and availability of metabolic substrates was investigated in mice. Fencamfamine (14 g/g per day orally for 6 weeks) reduced maximum swimming capacity by more than 40%. This effect could not be attributed to motor incoordination or a diminution of pre-swimming levels of metabolic substrates such as liver and muscle glycogen or blood glucose and non-esterified fatty acids. However, during swimming the hepatic and muscular glycogen stores were depleted more rapidly in the fencamfamine-treated animals. Thus it appears that fencamfamine leads more rapidly to a shortage of combustible substrates in the swimming animals.     

Lipid and protein histochemistry of enamel — Effects of fluoride

Summary Staining reactions for a number of histochemical procedures for lipophilic staining and protein were studied in the enamel matrix along the length of rat incisors. Sudan Black gave a positive stain across the whole thickness of very early enamel (up to 30 m) but this staining only continued as a narrow band close to the ameloblasts as the enamel matured. A variety of tests for protein produced almost identical staining patterns in enamel matrix up to 100 m thick. Since the pattern of lipid staining persisted, after using a number of procedures which could normally be expected to remove lipid, it is suggested that Sudan Black positive staining may be due to lipophilic protein rather than lipid itself. Fluoride did not significantly alter the staining reactions for lipid and protein but did proceduce matrix which was much more effectively stained by cross-linking agents FFDNB and FF sulphene.     

Molecular aspects of catechol and pyrogallol inhibition of liver microsomal lipid peroxidation stimulated by ferrous ion-ADP-complexes or by carbon tetrachloride

Summary Lipid peroxidation was induced in rat liver microsomes either by iron-ADP-complexes or by carbon tetrachloride in the presence of NADPH. Different compounds containing catechol or pyrogallol structures were examined for their activities to inhibit lipid peroxidation in both systems. In general, all compounds tested showed similar inhibitory activities on lipid peroxidation, if induced by ferrous ion-ADP-complexes or by carbon tetrachloride. This inhibition is explained by the suggestion that catechols and pyrogallos inhibit at the lipid site of the membrane, rather than at the enzymic site. Compounds not containing catechol or pyrogallol groups inhibited lipid peroxidation only weakly. O-Methylation resulted in a decrease of the inhibitory effect. Catecholor pyrogallol-derivatives which contained polar functional side chains, like carboxyl- or amino groups showed minor inhibitory effects compared to the esterified or N-alkylated compounds.Dihydroxychlorpromazine, 2-hydroxy-estradiol and 2-hydroxyethinylestradiol were the most effective inhbitors of microsomal lipid peroxidation (I₅₀-values of 1×10^–6 to 2×10^–7 M). The inhibitory activity of -tocopherol, glutathione and ascorbic acid, naturally occurring antioxidants, was about three orders of magnitude lower.Inhibition of lipid peroxidation induced by NADPH-cytochrome c reductase and iron-ADP-complexes in the presence of NADPH and liposomes was also observed with catechols.From our results we assume that the molecular structure of a catechol or pyrogallol functional group is a prequisite for an effective inhibition of lipid peroxidation by these chemicals. Furthermore, the results are discussed in relation to the requisite membrane affinity of catechols, pyrogallols and other antioxidants which might be used for inhibition studies on lipid peroxidation in vivo.     

绞股蓝总甙复合国产1号避孕片对健康妇女脂类代谢及血压的影响

本研究将180名已婚、一孩、年龄33±5岁,需要使用避孕措施的健康妇女随机分成6组,即IUD组、绞股蓝总甙加IUD组、1号OC片组、40mg、60mg、80mg绞股蓝总甙分别与1号OC片复合的3个试验组.用双盲法给药,连续服用6个月观察脂类代谢和血压的变化.结果显示:以IUD组和1号OC片组的数据为参比值.服用不同剂量绞股蓝总甙复合口服避孕药后无升高TG和TC的趋势,有显著升高HDL-C作用和使APOA_1水平上升的趋势;亦存在降低收缩压的趋势,对舒张压无明显影响,但在服药后3个月时HDL-C水平曾发生暂时性下降.     

Effect of chronic alcohol consumption on plasma lipid, vitamins A, and E in Korean alcoholics

This human study was conducted to evaluate the effect of chronic alcohol consumption on plasma concentrations of lipid and the antioxidative system in 44 Korean alcoholics and 45 age-, sex-, and nationality-matched nonalcoholic subjects. Plasma triacylglycerols and atherogenic index were higher in alcoholics than in control subjects. Plasma total cholesterol was not different among groups, but plasma high-density lipoprotein cholesterol was lower in alcoholics. There were positive correlations between ethanol consumption and plasma lipid peroxide and atherogenic index in all subjects; there were negative correlations between ethanol consumption and plasma high-density lipoprotein cholesterol in all subjects. There were no significant differences between alcoholics and control subjects in plasma concentrations of α-tocopherol, although plasma α-tocopherol/lipid tended to be lower in alcoholics. Plasma retinol was lower in alcoholics. These results suggest that chronic ethanol consumption can contribute to increased risk for vascular diseases in Korean alcoholics.     

不同频率电针对实验性肥胖大鼠脂代谢的影响

目的:通过观察不同频率的电针对实验性肥胖大鼠脂代谢的影响,探讨频率调节脂代谢异常的作用机制。方法:采用谷氨酸钠和高脂饮食诱导的下丘脑性肥胖大鼠模型,选取大鼠曲池、丰隆、三阴交、后三里、中脘和关元穴,采用2Hz、50Hz、100Hz频率针刺。测定大鼠体质量指数(Lee,s指数)、左肾周脂肪和大网膜脂肪湿重;用酶学终点法测血清三酰甘油(TG)、胆固醇(TC)的含量;用磷钨酸-镁沉淀法测血清高密度脂蛋白胆固醇(HDL-C)含量;用聚乙烯硫酸沉淀法测血清低密度脂蛋白胆固醇(LDL-C)含量。结果:与模型组比较,电针3组大鼠Lee,s指数、左肾周脂肪和大网膜脂肪湿重、血清TG、TC和LDL-C含量均显著降低(P<0.05或P<0.01),血清HDL-C含量显著升高(P<0.05)。结论:2Hz、50Hz、100Hz电针频率降低大鼠Lee,s指数、调整脂代谢的作用有依次递减的趋势,50Hz电针频率似在降低脂肪重量上较2Hz和100Hz有优势。