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1.
K. K. Carroll  H. T. Khor 《Lipids》1971,6(6):415-420
Female Sprague-Dawley rats on semisynthetic diets containing 10% and 20% by weight of corn oil developed more mammary adenocarcinomas after treatment with a single oral dose of 7,12-dimethylbenz(α)anthracene than similar rats on diets containing only 0.5% or 5% corn oil. Experiments with 10 different fats and oils fed at the 20% level indicated that unsaturated fats enhance the yield of adenocarcinomas more than saturated fats. Fibroadenomas and adenomas were also found in small numbers in all dietary groups but the yield did not seem to be influenced by level or type of dietary fat. The possible relevance of these findings to the incidence of breast cancer in humans is discussed. Presented at the ISF-AOCS World Congress, Chicago, September 1970.  相似文献   

2.
The lipid class and fatty acid composition profiles of mammary glands of female rats fed a nutritionally adequate diet are compared to those of tumors induced in the mammary glands by intravenous injection of dimethylbenz(a)anthracene of animals fed the same diet. Ca. 95% of the lipids of the mammary glands of the control group of animals consisted of triglycerides; glycolipids and phospholipids were present in only minor amounts. In contrast, the lipids of the mammary tumors contained much lower amounts of neutral lipids and higher concentrations of phospholipids. The glycolipid fraction was a minor component of both tissues but differed greatly in composition. The composition of the phospholipid and neutral lipid fractions, particularly the latter, of the mammary tumors also differed from that of the mammary glands of the control animals. The neutral lipids of the tumor tissues contained elevated levels of free fatty acids and cholesterol and much lower concentrations of triglyceride compared to the mammary gland lipids. Differences also were observed in the fatty acid composition of tumor and mammary gland lipid. The greatest differences occurred in the concentrations of polyunsaturated fatty acids which were generally much higher in the tumor lipids.  相似文献   

3.
The comparative effects of high-fat diets (20%, w/w) on eicosanoid synthesis during mammary tumor promotion in 7,12-dimethylbenz(a)anthracene (DMBA)-induced rats were studied using diets containing 20% primrose oil (PO), 20% menhaden oil (MO) or 20% corn oil (CO). Sprague-Dawley rats fed the PO or MO diet had 21% or 24% fewer adenocarcinomas, respectively, than rats fed the CO diet. Histologically (i.e., mitotic figures, inflammatory cell infiltration and necrosis), the CO-fed rats exhibited the highest frequency of changes within tumors. Plasma fatty acid composition was significantly altered by diet, reflecting the composition of the oils which were being fed. Only the plasma of PO-fed rats contained detectable levels of gamma-linolenic acid (GLA). Arachidonic acid (AA) levels were significantly higher (p<0.05) in PO-fed than in CO- or MO-fed rats. MO-fed rats had significantly higher levels of plasma palmitic acid, while palmitoleic, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids were detected only in MO-fed rats. As expected, linoleic acid (LA) and AA levels were lower (p<0.05) in the MO-fed rats than in PO- or CO-fed groups. The plasma of the CO-fed rats contained significantly higher levels of oleic acid. Eicosanoid synthesis in mammary carcinomas of rats fed the 20%-fat diets was 2–10 times higher than in mammary fat pads of control rats. The synthesis of PGE1 and LTB4 was significantly (p<0.05) higher in PO-fed rats than in CO-fed or MO-fed rats, although PGE values were significantly (p<0.05) higher in CO-fed rats than in Mo or PO groups. The synthesis of eicosanoids in both mammary fat pads and mammary carcinomas of MO-fed rats was lower (p<0.05) than in tissues of rats fed either CO or PO diets due to less AA precursor being fed and/or to competition between n−6 and n−3 fatty acids for cyclooxygenase and lipoxygenase. The ratios of monoenoic to dienoic eicosanoids in both mammary fat pads and mammary carcinomas were higher in the PO group than in the MO or CO groups. These results suggest that inclusion of GLA (PO feeding) or EPA and DHA (MO feeding) in the diet may decrease malignancy by altering eicosanoid profiles.  相似文献   

4.
Chylomicrons obtained from the thoracic duct of rats fed [3H]7,12-dimethylbenz(a)anthracene (DMBA), a polycyclic aromatic hydrocarbon, were infused intravenously into rats with bile fistulas. Over 17 hr, 55.9±3.2% (mean ±SEM) of the radioactivity was recovered in bile and 6.7±0.5% in urine. Minor amounts were deposited in liver, kidneys and epididymal fat pads. Injection of DMBA in ethanolic solution gave a similar pattern, while biliary DMBA metabolites resulted in higher recovery in urine and lower recovery in fat. In conclusion, the major part of chylomicron DMBA is rapidly excreted via the biliary route, while a fraction is probably retained in adipose tissue.  相似文献   

5.
Female rats have been fed high fat diets containing either polyunsaturated or saturated fat. After being fed either of the diets for 4 weeks, some of the animals received an intragastric dose of 7,12-dimethylbenz(a)anthracene (DMBA). At this point, the diets of half of the animals were interchanged so that animals previously fed the polyunsaturated fat diet were fed the saturated fat diet and vice versa. The cumulative incidence of tumor-bearing rats among DMBA-dosed rats was greater when the polyunsaturated fat diet was fed. The mean induction time of tumors decreased and the proportion of tumor-bearing rats which developed malignant tumors increased when the polyunsaturated fat diet was fed. This promotional effect of the polyunsaturated fat diet was exerted only when the diet was fed after DMBA administration.  相似文献   

6.
7.
The growth rate of a human mammary carcinoma, MX-1, was significantly reduced in athymic “nude” mice fed fish oil. Tumors from the fish oil-fed animals also showed a greater sensitivity to two anti-neoplastic agents, mitomycin C and doxorubicin. Mitochondria were isolated from control livers, host livers and tumors from fish oil-and corn oil-fed animals, and increased levels of 20∶5n−3 and 22∶6n−3 were found in mitochondrial lipids in all three tissues from the fish oil-fed animals. To investigate the effect of dietary n−3 fatty acids on lipid metabolism, the activity of the acyl-CoA:carnitine acyltransferase and three acyl-CoA desaturases were measured. Carnitine acyltransferase activity toward all four acyl-CoA substrates tested was markedly increased in mitochondria from liver by feeding fish oil. In mitochondria from tumors, feeding fish oil resulted in an increased activity toward only 18∶3n−3. These data suggest that fish oil may induce an increase in the oxidation of fatty acids. The Δ9-desaturase activity was decreased in microsomes from liver and tumor from fish oil-fed animals. However, both the Δ6 and Δ5 desaturases were increased in tumor and in control liver as a result of feeding fish oil. The Δ5 desaturase was not altered in microsomes from the host animals. The effect of fish oil on the Δ5 and Δ6 desaturases may involve alterations to metabolism of specific polyunsaturated fatty acids especially in the tumor tissue.  相似文献   

8.
The fatty acid composition of 16 brands of evening primrose oil (EPO) capsules was determined by capillary gas chromatography. Fourteen of these EPO brands contained γ-linolenic acid (GLA) levels between 7% and 10% (mean, 8.7; range, 1.9–10.5%) and there was generally good agreement between the level of GLA claimed by the manufacturer and the level determined by analysis. Low levels of the monoenes 22∶1 and 24∶1 found in some brands may indicate contamination of EPO with borage oil.  相似文献   

9.
10.
The carbonization of a non-hydrogenated extract (STC) from a low-rank coal (C, 83 wt%) of high fluidity was studied as single carbonizations and as co-carbonizations with additives, an objective being the production of needle-coke. The coke from STC had an optical texture of fine-grained mozaics; however, fractionation followed by co-carbonizations were effective in modifying carbonization properties. The lighter fraction of STC could give a coke with flow texture but in reduced yield. The addition of hydrogenated Ashland A240 pitch (HA240) in a quantity as low as 20% could effectively modify the carbonization properties of STC. A novel co-carbonization, in which an additive such as dihydroanthracene is recovered at the latter stage of the carbonization in the dehydrogenated form, was found to be effective also, although a relatively large amount of the additive was required. Among the non-hydrogenated additives, Ashland A240 pitch was the most effective in modifying the STC. The cocarbonization of fractionated STC reduced the quantity of additive required while maintaining a reasonable coke yield. Some practical aspects for the production of needle-coke from STC are discussed.  相似文献   

11.
以月苋草油为原料,经过皂化、脲包富集,碱性异构化等步骤的反应,制备共轭亚油酸CLA。GC-MS分析了这3个阶段的脂肪酸组成变化,产品中即含有CLA,又含有亚麻酸。研究了反应温度、反应时间、催化剂的用量对共轭转化率的影响,正交试验确定了最佳反应条件。  相似文献   

12.
Oils prepared from two varieties of peanuts and from a hybrid corn having linoleic acid concentrations substantially different from the respective commercial oils were compared with commercial oils for their effects on serum lipids of weanling female rats. In the first experiment, serum lipid patterns appeared to reflect linoleic acid content of the dietary oil. However, with a longer feeding period in the second experiment, serum lipid patterns were determined by the plant source of the dietary oil rather than its linoleic acid content; all peanut oils differed from both corn oils in their physiological effects. Diets containing triglyceride, hydrocarbon and sterol fractions obtained by liquid chromatography of peanut and corn oils were fed to female rats. The data provide no evidence that the hydrocarbon or sterol fractions of peanut oil are responsible for its unusual atherogenicity when fed as the sole fat source or that similar fractions from corn oil are protective against the effects of peanut oil.  相似文献   

13.
Dose-related effects of long-chain highly unsaturated n−3 fatty acids on the development ofN-nitrosomethylurea (NMU)-induced rat mammary tumors were assessed in female F344 rats. Four test groups (36 rats/group) were fed the following high-fat (HF) diets (23% fat, w/w): Group 1, 18% menhaden oil (MO) and 5% corn oil (CO); Group 2, 11% MO and 11.8% CO; Group 3,5% MO and 18% CO; Group 4, CO alone. A fifth group, serving as an internal control, was fed a low-fat diet containing 5% CO alone. Experimental diets were begun after initiation with NMU, and the experiment was terminated 31 wk later. Total tumor numbers in the five groups were 28, 16, 32, 26 and 11, respectively, indicating that the promotion phase of NMU-induced carcinogenesis was significantly suppressed only when equal parts of CO and MO (Group 2) were fed or when CO alone was fed at 5% (w/w). At high (Group 1) or low (Group 3) levels of MO, tumor numbers were indistinguishable from the HF CO group (Group 4). The same pattern was observed when assessed in terms of cumulative tumor incidence and multiplicity. However, when expressed in terms of final tumor incidence, dietary MO did not suppress tumor promotion in a statistically significant fashion at any concentration. Animals fed MO gained weight at the same rate as those fed CO, indicating that the presence of MO in the diet did not result in food avoidance behavior. Measurement of total serum cholesterol indicated an inverse trend with respect to the MO content of the diet. Analysis of serum fatty acid profiles indicated that the proportion of n−3 and n−6 polyun-saturated fatty acids (PUFA) in the serum reflected that of the diet. These results support the hypothesis that the relative proportions of dietary n−3/n−6 fatty acids play an important role in the suppression of experimental mammary tumorigenesis and suggest that changes in circulating cholesterol or n−3 PUFA levels, induced by dietary MO, are not directly related to tumor development. Presented in part at the 81st Annual Meeting of the American Association for Cancer Research, Washington, D.C., May 1990  相似文献   

14.
Weanling rats were fed diets containing 10% menhaden oil (MO) or 10% corn oil-lard (1∶1, COL) with low (≤5 IU/kg) or supplementary (35 IU/kg) vitamin E for six weeks. The rats were killed 30 min after injection with 24 mg iron/kg as ferrous chloride because thiobarbituric acid-reactive substances (TBARS) in liver homogenates were highest at 30 min after injection of iron into rats fed a standard diet. Tissue homogenates were used either without incubation (zero-time) or after incubation at 37°C for 1 hr. In addition to TBARS and conjugated dienes, headspace hexanal and total volatiles (TOV) determined by capillary gas chromatography were useful indices of lipid peroxidation since they were decreased by vitamin E supplementation and were increased with increasing iron dose. Regardless of the dietary lipid used, vitamin E supplementation decreased headspace hexanal, TOV, TBARS and conjugated dienes in both zero-time and incubated homogenates of liver and kidney. Dietary MO increased TBARS in both zero-time and incubated homogenates of tissue from rats injected with iron. In contrast, dietary MO decreased hexanal and TOV in incubated tissue homogenates. The study demonstrated the usefulness and limitations of using hexanal and TOV as indices of lipid peroxidation.  相似文献   

15.
Three groups of rats were fed diets with either 10 weight percent (wt%) of evening primrose oil, safflower oil or soybean oil for 11 weeks. Diets contained 7.1 wt% linoleic acid +0.8 wt% γ-linolenic acid, 7.6 wt% linoleic acid, or 5.3 wt% linoleic acid +0.7 wt% α-linolenic acid, respectively. In liver mitochondria as well as in heart, dietary γ-linolenic acid did not affect the fatty acid profiles of phosphatidylcholnes (PC), phosphatidylethanolamines (PE) or cardiolipins (CL), whereas dietary α-linolenic acid caused an increased formation of (n−3) polyunsaturated fatty acids (PUFA). The liver Δ6− and Δ5-desaturase activities determined in vitro were not affected by the dietary fats. In brain PE, which are rich in C22− and C20-(n−3) PUFA, as well as in testes PC and PE, which are rich in (n−6) PUFA, no effects were found from a partial replacement of dietary linoleic acid with γ-linolenic acid or α-linolenic acid. In kidney PC, PE, phosphatidylinositol (PI) and CL, 20∶3(n−6) was moderately elevated to ca. 1% following intake of γ-linolenic acid, whereas partial replacement of linoleic acid with α-linolenic acid was followed by increased deposition of 22∶6(n−3) in PC and PE of testes and kidney. Thus, no general effect of evening primrose oil on the content of (n−6) PUFA in rat tissue phospholipids was observed, wheras a significant incorporation of γ-linolenic acid into liver and adipose tissue triglycerides was found.  相似文献   

16.
研究了原子吸收光谱法测定蒽油中铁、钾、镁、钠、钙、铜等金属含量。先将蒽油试样经过灼烧灰化后,用盐酸溶解,采用火焰原子吸收光谱法测定其中的铁、钾、镁、钠、钙、铜等金属含量。实验表明,铁和铜含量在0~5mg/L范围内,钾和镁含量在0~0.4mg/L范围内,钠含量在0~0.8mg/L范围内,钙含量在0~8mg/L范围内均显现良好的线性关系,相关系数均为r=0.999,铁、钾、镁、钠、钙、铜加标回收率均在95%~105%内。  相似文献   

17.
Diets rich in linoleic acid (CO) from corn oil, or in linoleic acid and either α-linolenic acid (LO) based on linseed oil or n−3 fatty acids (MO) from menhaden oil were fed to male and female Cynomolgus monkeys for 15 wk. In the liver a 40% reduction of α-tocopherol occurred in the MO group relative to the CO and LO groups followed by increased formation of lipofuscinin vivo. A four-fold increase of α-tocopherol in the MO diet (MO+E) brought the level in the liver to that found with CO and LO. The increased peroxidation in the MO group in the liver phospholipids was associated with the replacement of 60% of the n−6 fatty acids by n−3 fatty acids from menhaden oil. Similar fatty acid profiles were found in groups fed MO and MO+E, respectively. Compared to the CO fed group, feeding α-linolenic acid only resulted in a slight incorporation of n−3 fatty acids in the liver membranes mainly due to a direct incorporation of α-linolenic acid. However, in monkeys fed menhaden oil more than 30% of the total fatty acids in the liver phospholipids were n−3 fatty acids. The various diets did not influence the activity of liver catalase (EC 1.11.1.6) nor superoxide dismutase (EC 1.15.1.1), but glutathione-peroxidase activity (EC 1.11.1.9) was higher in monkeys fed the MO diet. The catalase activity in females was 20% higher than in males. In anin vitro assay, liver microsomes from monkeys fed the MO diet or the MO diet supplemented with tocopherol produced similar amounts of thiobarbituric acid reactive substances and at a much higher rate than microsomes from the CO and LO groups. It appeared that α-tocopherol did not protect long-chain n−3 C20 and C22 fatty acids as well as n−6 fattya acids against peroxidation. The present data showed that monkeys were not fully able to compensate for increased peroxidative stress but a four-fold supplement of vitamin E to the diets reduced the oxidation.  相似文献   

18.
The potential effects of oil specimens related to cases of toxic oil syndrome (TOS) on the liver microsomal lipid composition from guinea pigs were investigated. For four weeks, animals were fed diets supplemented with either “case oil” (oil related to cases of TOS) or “control oil” (oil unrelated to cases of TOS), either previously heated or not. Results were compared with those from guinea pigs fed the same diet with no oil. The administration of case oil produced changes in liver microsomal lipid composition. Statistically significant differences were also found between heated case and heated control oils. The cholesterol/phospholipid molar ratios and the major phospholipid class distribution were unaffected under these diet conditions. However, increases in the relative contents of linoleic and arachidonic acids and, simultaneously, a reduction in palmitic and palmitoleic acid levels were observed by diet effects. Heated oil administration decreased the saturated/unsaturated ratios in all cases. Our data suggest that changes observed in the fatty acid composition are attributable to the free fatty acid contents of administered oils. The toxic constituents of case oil seem to be able to alter the liver microsomal lipid composition.  相似文献   

19.
蒽油加氢尾气回收装置无法对低压硫化氢进行回收,因此需要对尾气回收装置进行改造。通过对尾气回收装置中的水洗塔、硫氢化钠反应器进行改造,使尾气全部回收,减少硫化氢气体排放,并提高硫氢化钠产量,取得良好的社会及经济效益。  相似文献   

20.
Ohtake T  Kimura M  Takemura H  Hishida A 《Lipids》2002,37(4):359-366
Although it is well known that dietary lipids affect the course of glomerulonephritis in rats and humans, the precise mechanisms involved have not been fully elucidated. The aim of this study was to investigate the effects of different types of dietary lipids (fish oil and vegetable oil) on daunomycin (DM)-induced nephropathy in mice fed on soybean oil (SO) or cod liver oil (CLO). Urinary protein excretion, serum albumin, creatinine, total cholesterol, and TG were measured, and glomerular histological changes were evaluated. Antioxidant enzymes were also measured, along with the levels of lipid peroxide, GSH, thromboxane (Tx) B2′ and 6-keto prostaglandin F in renal cortical tissue. Dietary CLO significantly reduced urinary albumin excretion and ameliorated the histological changes induced by DM. The increase of tissue lipid peroxide levels seen in SO-fed mice was suppressed in CLO-fed mice, whereas CLO-fed mice showed higher GSH levels than SO-fed mice throughout the experiment. In addition, renal tissue GSH peroxidase activity was significantly higher at 72 h after DM injection in CLO-DM mice than in SO-DM mice. Both renal cortical TxB2 and 6-keto PGF levels were significantly lower in CLO-DM mice than in SO-DM mice. These results suggest that inhibition of oxidative damage by dietary CLO played an important role in the prevention of DM nephropathy in this mouse model. The effect of CLO was closely associated with the inhibition of Tx synthesis.  相似文献   

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