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1.
Owe Johnson 《Lipids》1974,9(1):57-60
The effect of ethanol, given by gastric tube or by intraperitoneal injection, on the liver triglyceride concentration in fasted
and ad libitum fed rats was investigated. Ethanol, independent of the route of administration, increased the liver triglyceride
concentration in fasted rats during an 8 hr period but caused a much smaller increase in the ad libitum fed rats. The incorporation
of intravenous injected3H-oleic acid into the liver triglycerides increased significantly after ethanol feeding in fasted but not in fed rats. Based
upon this and the plasma free fatty acid concentrations, it is concluded that ethanol causes a marked increase in the utilization
of plasma free fatty acids for synthesis of liver triglycerides in fasted but not in fed rats. It is suggested that this is
part of the explanation for the different responses to ethanol of the liver triglyceride concentrations in fasted and fed
rats. 相似文献
2.
Three major density classes of lipoproteins and a residual protein (d>1.21) were isolated by ultracentrifugation from plasma
of fasted, fed normal, and choline-deficient rats. Lipid extracts were obtained from total plasma and the various density
classes of lipoproteins, and each extract was examined in detail by thin layer and gas chromatographies. The results indicated
essentially identical compositions of molecular species of phosphatidyl choline, which suggested their rapid equilibration
among the different plasma lipoprotein classes. In contrast, the molecular species of the triacylglycerols and cholesteryl
esters showed significant differences among the chylomicrons, very low and low, and high density lipoproteins, which excluded
the possibility of their ready equilibration in vivo. Omission of choline from diet resulted in a sharp and statistically
significant decrease in all lipid components of the very low and low density lipoproteins within 2 days. After 10 days of
choline deficiency, the lipid levels of chylomicrons and very low and low density lipoproteins were ca. one-half the levels
found in the choline supplemented animals, and there were discernible distortions in their lipid composition. Reintroduction
of choline led to a prompt return to normal levels and lipid composition of both chylomicron and very low and low density
lipoprotein fractions. The lack of equilibration of the triacylglycerols among the lipoprotein classes under normal conditions
and in choline deficiency demonstrates an as yet unrecognized source of compartmentation of plasma lipids. 相似文献
3.
Nicotine, a major component of cigarette smoke, plays an important role in the development of cardiovascular disease and lung
cancer in smokers. The effect of nicotine on lipoprotein metabolism was studied using rats as the experimental animal. There
was a significant increase in the total cholesterol, phospholipids, and triglycerides as well as the amount of lipids associated
with very low density lipoprotein (VLDL) and low density lipoprotein (LDL) in sera of nicotine-treated rats. The incorporation
of 3H labeled leucine into the apo B was found to be increased both in the medium and associated cells in the hepatocytes isolated
from nicotine-treated rats indicating an increased synthesis and secretion of the apo B containing lipoproteins. This was
further confirmed by the higher incorporation of 14C acetate into total and individual lipids of LDL and VLDL secreted into the medium as well as that associated with different
lipids in the cell layer. The activity of lipoprotein lipase in extrahepatic tissues and plasma lecithin cholesterol acyltransferase
activity were significantly lower in nicotine-treated rats. These results indicate that nicotine exerts hyperlipidemic effects
particularly by increasing the synthesis and secretion of triglyceride-rich lipoproteins. Since nicotine is one of the major
hazardous components present in cigarette smoke and tobacco, one can extrapolate that the deleterious effect exerted by nicotine
on rats extends to cigarette smokers and those who use other forms of tobacco. 相似文献
4.
Jerome L. Hojnacki Joanne E. Cluette-Brown Randall N. Deschenes John J. Mulligan Thaddeus V. Osmolski Nicholas J. Rencricca Joseph J. Barboriak Joseph A. Jakubowski 《Lipids》1991,26(11):884-890
The present study was designed to investigate the effect of ethanol (EtOH) dose on low density lipoprotein (LDL) and platelet
composition. Male squirrel monkeys were divided into three groups designated Control, Low, and High EtOH, and fed isocaloric
liquid diets containing 0%, 12%, and 24% of calories as EtOH, respectively. After four months of treatment, monkeys fed the
12% alcohol dose had LDL and platelet cholesterol concentrations similar to Controls. By contrast, platelet membranes from
High EtOH animals contained significantly more cholesterol which was associated with higher levels of plasma LDL cholesterol
and apolipoprotein B. Blood platelet count, size, and mass were similar for all groups and circulating platelet aggregates
were absent in the two alcohol cohorts. Despite elevations in platelet cholesterol mass and thromboxane A2 (TXA2) precursor, phospholipid arachidonate, platelet responsiveness, measured as thromboxane formed in response to a collagen
challengein vitro, and the cholesterol/phospholipid molar ration, were not significantly altered by high dose alcohol. Normal platelet activity
in High EtOH monkeys may have resulted from a significant increase in the platelet phospholipid polyunsaturated/saturated
fatty acid ratio and a non-significant increase in platelet phospholipid mass, both of which would have a fluidizing effect
on platelet membranes. Our data indicate that low EtOH intake has no effect on platelet composition and function while unfavorable
platelet cholesterol enrichment following consumption of high dose ethanol may arise from elevations in plasma LDL. Potentially
thrombogenic (TXA2 formation, platelet aggregate formation) consequences of increased platelet cholesterol in squirrel monkeys fed high levels
of alcohol may be averted by compensatory physicochemical changes in platelet membrane lipid composition although persistent
elevations in circulating LDL may contribute to increased risk of cardiovascular disease. 相似文献
5.
Comparative studies on composition of cardiac phospholipids in rats fed different vegetable oils 总被引:5,自引:5,他引:0
J. K. G. Kramer 《Lipids》1980,15(9):651-660
Male Sprague-Dawley rats were fed diets for 1 or 16 weeks, containing 20% by weight vegetable oils differing widely in their
oleic, linoleic and linolenic acid content. No significant changes were observed in the level of the cardiac lipid classes.
The fatty acid composition of the 2 major phospholipids, phosphatidylcholine and phosphatidylethanolamine, showed a remarkable
similarity between diets in the concentration of total saturated, C22 polyunsaturated and arachidonic acids. Monounsaturated
acids were incorporated depending on their dietary concentration, but the increases were moderate. Dietary linolenic acid
rapidly substituted C22 polyunsaturated fatty acids of the linoleic acid family (n−6) with those from the linolenic acid family
(n−3). The results suggest that dietary linolenic acid of less than 15% does not inhibit the conversion of linoleic to arachidonic
acid but the subsequent conversion of arachidonic acid to the C22 polyunsaturates was greatly reduced. Significant amounts
of dietary monounsaturated fatty acids were incorporated into cardiac cardiolipin accompanied by increases in polyunsaturated
fatty acids, apparently to maintain an average of 2 double bonds/molecule. The cardiac sphingomyelins also accumulated monounsaturated
fatty acids depending on the dietary concentration. It is quite evident from the results of this study that the incorporation
of oleic acid and the substitution of linolenic for linoleic acid-derived C22 polyunsaturated fatty acids into cardiac phospholipids
was related to the dietary concentration of these fatty acids and was not peculiar to any specific oil. Even though it is
impossible to estimate the effect of such changes in cardiac phospholipids on membrane structure and function, results are
discussed which suggest that the resultant membrane in the Sprague-Dawley male rat is more fragile, leading to greater cellular
breakdown and focal necrosis.
Contribution No. 914 from the Animal Research Institute. 相似文献
6.
Changes in dietary lipid intake are known to alter the fatty acid composition of cardiac muscle of various animals. Because
changes in cardiac muscle membrane structure and function may be involved in the pathogenesis of arrythmia and ischemia, we
have examined the effects of dietary lipid supplements on the phospholipid distribution and fatty acid composition of rat
atria and ventricle following 20 weeks feeding of diets supplemented with either 12% sunflower-seed oil or sheep fat.
Neither lipid supplement produced significant changes in the proportions of cholesterol, total phospholipids or phosphatidylcholine,
phosphatidylethanolamine or diphosphatidylglycerol,—the phospholipid classes that together account for more than 90% of the
total phospholipids of rat cardiac muscle. Significant changes were found in the profiles of the unsaturated fatty acids of
all 3 phospholipid components of both atria and ventricle. Although similar, the changes between these tissues were not identical.
However, in general, feeding a linoleic acid-rich sunflower seed oil supplement resulted in an increase in the ω-6 family
of fatty acids, whereas feeding the relatively linoleic acid-poor sheep fat supplement decreased the level of ω-6 fatty acids
but increased the levels of the ω-3 family, resulting in major shifts in the proportions of these families of acids. In particular,
the ratio of arachidonic acid: docosahexaenoic acid (20∶4, ω-6/22∶6, ω-3), which is higher in all phospholipids of atria than
ventricle, is increased by feeding linoleic acid, primarily by increasing the level of arachidonic acid in the muscle membranes.
As dosahexaenoic acid does not occur in the diet, the increase in this acid which occurs after feeding animal fat, presumably
arises from increased conversion of the small amounts of linolenic acid in all diets when the amount of linoleic acid present
is reduced. 相似文献
7.
No mortality was observed in 6 week old male Sprague-Dawley rats subjected to cold at 4 C for 3 weeks and fed either a control
diet (Chow) or a semisynthetic diet containing 20% by wt rapeseed oil high in erucic acid (23.6%). All rats fed the Chow diet
and 17 of 20 rats fed the rapeseed oil-containing diet survived 4 weeks in the same environment. Three rats on the latter
diet died of self-mutilation. Marked myocardial lipidosis as well as a large accumulation of 20∶1 and 22∶1 was observed in
the hearts of rats fed the rapeseed oil-containing diet. Five of 20 rats on the Chow diet and 2 of 20 rats on the rapeseed
oil-containing diet had focal necrotic areas in the myocardium. 相似文献
8.
J. K. G. Kramer 《Lipids》1973,8(11):641-648
Studies are reported on the effect of feeding diets containing rapessed oils differing in their erucic acid content to male
weanling rats for 16 weeks. Rapeseed oil high in erucic acid depressed growth. Total lipids, lipid phosphorous and cholesterol,
in the livers were not significantly different between the experimental groups. The fatty acid composition of the total liver
lipids, the neutral lipids, phosphatidylethanolamine and phosphatidylcholine are documented. Erucic and eicosenoic acids were
found in all lipid classes at the same relative concentration; the amount being incorporated was proportional to that found
in the dietary oil. The positional analysis of phosphatidylethanolamine and phosphatidylcholine are presented. Erucic acid
was incorporated preferentially at position two of these phospholipids, whereas, twice the level of eicosenoic acid was found
at position one, compared to that which occurred at the two position.
This article represents part of an extensive experiment carried out by Agriculture Canada to investigate the nutritional value
of rapeseed oils (see ref. 15).
Contribution No. 497 from the Animal Research Institute. 相似文献
9.
Feeding rats diets containing brominated corn oil or di- or tetrabromostearate as the monoglyceride produced changes in fatty
acid composition of liver lipids. Those changes associated with the feeding of brominated corn oil or tetrabromosterates could
be explained by the accumulation of triglyceride, and the changes associated with the feeding of dibromostearate could result
from the proliferation of a membrane system. A unique response to the feeding of diets containing brominated corn oil is an
increase in the level of γ-linolenic acid. 相似文献
10.
This report describes the daily changes in fatty acid composition and fatty acid desaturation in rats feeding on a complete
diet and a fat-free diet successively. Rats on a complete diet showed a good homeostasis in the percentage of fatty acid in
plasma, with a possible palmitic acid rhythm, but the fat-free diet initiated an essential fatty acid-deficient pattern in
a few hours. The light-dark period in animals feeding on a complete diet motivates a feeding rhythm that causes changes in
linoleic and arachidonic acids in the whole liver and microsomes that are related to Δ6 and Δ5 desaturase activities. The
patterns of Δ6 and Δ5 desaturase changes were different. Linoleic acid intake during the dark periods (complete diet feeding)
caused a decrease of Δ6 desaturase activity and the activation of Δ5 desaturation that led to an increase of arachidonic acid
biosynthesis. The feeding of a fat-free diet eliminated the rhythm observed in linoleic and arachidonic acid composition in
the liver and changed the desaturase rhythms. The Δ9 desaturase activity in the liver also showed a daily rhythm in the complete-diet
period that disappeared with the change to a fat-free diet, while the activity increased markedly. A negative correlation
existed between the percentage of linoleic acid in the liver and the Δ9 desaturase activity. However, no correlation was found
between Δ9 desaturase activity and the percentage of 16∶1 and 18∶1 in the complete-diet period. 相似文献
11.
Changes in serum lipoprotein profiles were characterized in Donryu rats subcutaneously implanted with an ascites hepatoma
line of AH109A cells and the effect of a new hypolipidemic agent with a structure of 4-(4′-chlorobenzyloxy)benzyl nicotinate
(KCD-232) was estimated. With the growth of hepatoma for periods of up to three weeks, a striking decrease in the high density
lipoprotein (HDL) fraction and an enormous increase in the VLDL+LDL (very low density lipoprotein+low density lipoprotein)
fraction were found in hepatoma-bearing rats when either precipitation method or electrophoresis was used. These lipoprotein
profiles were not influenced by sex. Judging from the electrophoretogram, the increase in VLDL+LDL fraction was due mainly
to an increase in LDL fraction. The oral administration of KCD-232 significantly suppressed the hepatoma-induced increase
in VLDL+LDL with little or no influence on the hepatoma-induced decrease in HDL. There existed a positive correlation between
the hepatoma weight and (VLDL+LDL)-cholesterol concentration and a negative one between hepatoma and HDL-cholesterol. 相似文献
12.
Male Wistar rats were fed rapeseed oil containing high or low levels or erucic acid for 20 weeks, and changes in the fatty
acid composition of cardiac mitochondrial phospholipids were studied. Treatment with rapeseed oil containing 46.2% erucic
acid showed incorporation of 22∶1 (5.6%) into isolated cardiolipin from heart mitochondria. After high or low (3.7%) erucic
rapeseed oil feeding, linoleic acid was slightly incorporated into cardiolipin. Moreover, both of these rapeseed oils induced
a significant increase of linoleate-arachidonate ratio in phosphatidylethanolamine and phosphatidylcholine. This ratio was
also significantly increased in fatty acids esterified to the β-position of these phospholipids. On the basis of such results,
we have to consider the role of linolenic acid which is present at a high level in the different rapeseed oils used, as a
possible inhibitor of heart microsomal enzymes involved in linoleate arachidonate conversion. Such alterations might account
for mitochondrial fragility and myocardial lesions obtained in long term rapeseed oil feeding experiments.
ERA-CNRS no 070497 相似文献
13.
14.
The composition of liver phospholipids was studied in rats fed for 4 weeks diets containing 0, 100 or 300 mg 13-cis retinoic acid per kg diet. There was a significant decrease in phosphatidylcholine content, whereas the levels of phosphatidylethanolamine were slightly increased in liver phospholipids of rats fed 13-cis retinoic acid. The fatty acid composition of total phospholipids, PC, PE, and PI+PS fractions revealed a general increase in the levels of 18∶2 and 20∶3ω6, whereas the levels of 20∶4ω6 and C22 fatty acids were reduced in most of the hepatic phospholipids isolated from rats fed 13-cis retinoic acid containing diets. A decrease in the double-bond index of fatty acids was also observed in phospholipids of rats fed 13-cis retinoic acid. The data suggest that high levels of 13-cis retinoic acid may possibly be influencing the activities of microsomal desaturating and chain-elongating enzymes in the liver. 相似文献
15.
Glucose administered to fasted rats caused a marked stimulation in hepatic cholesterogenesis and cholesterol 7 alpha-hydroxylation, and an increase in biliary excretion of cholesterol and total bile acids. The excretion of cholic acid was not incluenced during the first few hr after glucose administration, but was significantly increased after 5 hr. Chenodeoxycholic acid showed a similar change, but the increase was only ca. one tenth of that of cholic acid. The excretion of deoxycholic acid was markedly increased by 1 hr, but gradually decreased thereafter. Pretreatment with neomycin abolished the increase in deoxycholic acid by fasting and glucose administration. Other bile acid components showed no significant change. It thus was presumed that cholesterol endogenously synthesized in the liver was metabolized mainly to cholic acid. In contrast, exogenous cholesterol was metabolized mainly to chenodeoxycholic acid. During the period of the acute enhancement of cholic acid formation from the endogenous cholesterol, biliary excretion of deoxycholic acid was increased. This probably occurred through the depression of 7 alpha-rehydroxylation of deoxycholic acid, or through the enhancement of microbial formation of deoxycholic acid in the lumen, and through the increase of intestinal absorption. 相似文献
16.
Arne T. Høstmark Øystein Spydevold Einar Lystad Eva Kristensen Ida Goffeng Bay 《Lipids》1982,17(7):489-499
The effect of varying the dietary sunflower oil/sucrose (SO/SU) ratio on rat plasma lipid concentration and lipoprotein distribution
was studied. Four groups of 10 rats were fed for 4 weeks diets with varying SO/SU ratios. Lipoprotein components were then
estimated in whole plasma and after cumulative density ultracentrifugation. Whole plasma triacylglycerol (TG), total cholesterol
(TC) and free cholesterol (FC) decreased with increasing SO/SU ratio; the CE/FC ratio increased, because CE remained virtually
unaltered. Plasma TG-lowering was due to a decrease in VLDL and LDL-TG. Protein, CE and FC in d=1.063–1.100 g/ml (HDL2b) and d=1.100–1.125 g/ml (HDL2a) lipoproteins decreased upon increasing the SO/SU ratio. In contrast, in d=1.125–1.200 g/ml (HDL3) lipoproteins, there was a concomitant increase in these components. Although increasing the SO/SU ratio effected more protein
and CE transportation in HDL3 and less in HDL2, the total amount of these components in high density lipoproteins (d=1.063–1.200 g/ml) remained constant. Apo A-I and apo
C-III decreased in HDL2 but increased in HDL3 upon increasing the SO/SU ratio. Also, HDL2 apo E, and the apo C-II/apo C-III and small apo B/large apo B ratios in VLDL and LDL were lowered by increasing the SO/SU
ratio. The hepatic VLDL-TG output during isolated liver perfusion was lowest in rats fed the diet with the highest SO/SU ratio.
In perfusate, like in plasma, the VLDL and LDL apo C-II/apo C-III ratio, as well as the small apo B/large apo B ratio, decreased
upon increasing the dietary SO/SU ratio. The results indicate that there can be appreciable diet-dependent variations in plasma
HDL subgroup distribution in spite of unchanged total HDL levels. 相似文献
17.
Chronic administration of ethanol failed to stimulate the hepatic rate of cholesterol synthesis in meal-fed rats. In contrast,
chronic ethanol feeding caused a 50% inhibition in the rate of incorporation of [4-14C] cholesterol to bile acids in the bile-duct cannulated rats. It is, therefore, suggested that the decreased rate of cholesterol
degradation to bile acids may play an important role in ethanol-induced accumulation of cholesterol in liver. 相似文献
18.
F. Abdullah M. Whiteford G. Mathiak P. Ovadia A. Rudolph L. F. Neville R. Rabinovici 《Lipids》1997,32(4):377-381
The present study investigated the effect of liposome-encapsulated hemoglobin (LEH), an experimental oxygen-carrying resuscitation
fluid, on triglyceride, total cholesterol, and low density lipoprotein (LDL), and high density lipoprotein (HDL) cholesterol
measurements. In vivo, the intravenous infusion of LEH (5.6 mL/kg, n=6) elevated serum triglycerides (+92% vs. baseline, P<.05), total cholesterol (+25% vs. baseline, P<.01), LDL cholesterol (+72% vs. baseline, P<.01) and had no effect on serum HDL cholesterol. In addition, LEH did not alter the elevation in serum triglycerides (+302%
vs. baseline, P<.01) and LDL cholesterol (+86% vs. baseline, P<.01) induced by lipopolysaccharide (3.6 mg/kg, i.v., n=6). Ex vivo, measurements of triglycerides and total cholesterol as well as LDL and HDL cholesterol in whole blood from naive rats were
not changed by the addition of LEH (0–50%, n=6). In vitro, the addition of a fixed concentration of LEH (50%, n=6) to varying concentrations of cholesterol solution (0–50%), or vice versa, had no effect on cholesterol determination. It is therefore concluded that LEH only minimally affects serum levels of triglycerides,
total cholesterol, LDL cholesterol, and HDL cholesterol and does not interfere with their measurement. 相似文献
19.
The inverse relationship between zinc (Zn(++)) and prolactin (PRL) was detected in in vitro studies, whereas in vivo results are contradictory. In order to evaluate this controversial subject we studied patients with hyperprolactinemia. Basal serum Zn(++) levels and serum PRL response to acute and chronic oral Zn(++) administration were evaluated in seven patients with prolactinomas and one with idiopathic hyperprolactinemia. Serum PRL levels did not change after acute oral Zn(++) administration (37.5 mg), although Zn(++) levels increased from 1.11+/-0.15 to 2.44+/-0.39 mug/mL (P<0.05). ZnZn(++) administration (47.7 mg daily) during 60 days increased serum Zn(++) levels from 1.11 +/- 0.15 to 1.59 +/- 0.58 mug/mL (p < 0.05) but caused no change in serum PRL levels. The TRH tolerance test (200 mug) was performed before and after 60 days of Zn(++) administration, and PRL response to TRH was unchangeable and similar in both tests. We concluded that acute or chronic Zn(++) administration does not inhibit PRL secretion in basal condition or by TRH effect in hyperprolactinemic patients. 相似文献
20.
Male F-344 rats were fed a choline-free (CF) diet, and changes in phospholipid content, phospholipid fatty acids and phospholipase
A2 activity in liver nuclei and microsomes were examined during the first 72 hr. Both nuclei and microsomes showed a decrease
in phosphatidylcholine (PC) content. Microsomes showed an increase in PC arachidonate while nuclei showed a decrease. Also,
microsomes showed increased activity of phospholipase A2 (PLA2) while nuclei did not. These observations are consistent with the hypothesis that the absence of diene conjugates in liver
microsomes in the rats on the CF diet may reflect the increased rate of removal of peroxidized fatty acids by phospholipase
A2. 相似文献