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1.
Kiyohisa Uchida Haruto Takase Yasuharu Nomura Takashi Satoh Hirotsune Igimi Nozomu Takeuchi 《Lipids》1997,32(4):383-390
Serum cholesterol, triglyceride and phospholipid levels, liver cholesterol concentration, bile flow, biliary cholesterol,
phospholipid and bile acid secretion rates, fecal sterol and bile acid levels and their bile acid compositions were examined
in young-old parabiotic rats and compared with those in young and old control rats and young-young parabiotic rats. Bile acid
composition was expressed in terms of the cholic acid group/chenodeoxycholic acid group (CA/CDCA) ratio. Body weight (BW)
gain decreased after parabiosis especially in old rats, but the liver weight (g/100 g BW), diet-intake, feces dry weight,
liver cholesterol concentration and fecal sterol level were almost the same in all the groups. The biliary bile acid secretion
rate was higher and the fecal bile acid level was lower in old rats than those in young rats but both the levels became comparable
with those in young rats after parabiosis of old rats with young rats. Young rats, however, showed no changes in these levels
after parabiosis. The serum cholesterol level and the biliary and fecal CA/CDCA ratios in old rats were higher than those
in young rats but decreased after parabiosis with young rats, although they were still higher than those in young rats. The
serum cholesterol level in young rats increased after parabiosis with old rats, but not after parabiosis with young rats,
and the fecal bile acid level and the CA/CDCA ratio were not changed in either case. It is concluded from these findings that
the serum cholesterol level and the CA/CDCA ratio increased with age and that these increases were prevented after parabiosis
with young rats, while young rats, although their serum cholesterol level was increased, showed no increase in the CA/CDCA
ratio after parabiosis with old rats. 相似文献
2.
The bile acid pool was found to be ca. 50 μmoles/100 g body wt in male and female rats maintained on standard laboratory chow
and ca. 30 μmoles/100 g body wt in those maintained on a standard semisynthetic diet. The distribution of bile acids within
the pool was similar in plasma, liver, and intestinal tract, except for a higher concentration of deoxycholic acid in the
intestinal tract. Sex differences in bile acid composition were found to be influenced by the dietary regimen of the animals. 相似文献
3.
The hepatic metabolism of deoxycholic acid was studied using the isolated perfused rat liver technique. In 20 perfusions, 10 involving the livers of male rats and 10 involving the livers of female rats, 30 μmoles deoxycholic acid was added to the perfusion medium. In 10 perfusions, 5 male and 5 female, 1 μmole deoxycholic acid was added to the perfusion medium. In 10 of the high dose studies and in the 10 low dose studies, 1 μCi deoxycholic acid-C-24-C14 also was added. The deoxycholic acid was added to 100 ml perfusion medium after 2 hr of baseline perfusion, and the studies were continued another 3 hr. Biliary bile acids were analyzed by combined thin layer and gas chromatography, and the radioactivity content of the perfusion medium and liver was documented. Although there was no sex difference in total bile acid secretion in the high dose studies, there were sex differences in the bile acid secretion rate and in the quantitative secretion of individual bile acids. The biliary secretion of deoxycholic acid and cholic acid was immediate in the female studies and delayed in the male, and the amounts of cholic acid and sulfated deoxycholyl-taurine secreted were considerably greater in the male studies. In the low dose studies the isolated perfused liver of the female rat converted more deoxycholic acid to cholyl-taurine than did that of the male rat. There are sex differences in the hepatic metabolism of deoxycholic acid. In contrast to those found in the case of chenodeoxycholic acid, these sex differences are not impressive when physiological amounts of deoxycholic acid are presented to the liver. 相似文献
4.
Current dogma of bile acid synthesis in mammals insists that hydroxylation of the ring structure at C-12 precedes side chain oxidation, and that chenodeoxycholic acid is not converted to cholic acid under normal conditions. This report concerns the conversion of chenodeoxycholic acid to cholic acid by isolated, perfused rat liver. Results indicate that isolated perfused rat liver has a definite, but limited, capacity for synthesis of cholic acid from chenodeoxycholic acid. 相似文献
5.
Catanozi S Rocha JC Passarelli M Mesquita CH Suguiama VY Guzzo ML dos Santos Filho A Quintão EC Nakandakare ER 《Lipids》2006,41(7):663-668
Dyslipoproteinemia of the Nagase analbuminemic rat (NAR) is characterized by elevated concentrations of VLDL and LDL attributed
to increased rates of liver lipoprotein synthesis. Increased lysophosphatidylcholine (LPC) in NAR HDL has been attributed
to high plasma LCAT activity. We show here that, as compared with Sprague-Dawley rats (SDR), NAR plasma triacylglycerol (TAG),
total cholesterol (TC), HDL TAG, protein, total phospholipids (PL), LPC, and PS are increased. These alterations rendered
the NAR HDL particle more susceptible to the activity of the enzyme hepatic lipoprotein lipase (HL), which otherwise was unaltered
in our study. Fractional catabolic rates in blood of the autologous 125I-apoHDL (median and lower quartile values), were, respectively, 0.231 and 1.645 (n=10) in NAR as compared with 0.140 and 0.109 (n=10) in SDR (P=0.012), corresponding to synthesis rates of HDL protein of 89.8±33.7 mg/d in NAR and 17.4±6.5 mg/d in SDR (P=0.0122). Furthermore, Swiss mouse macrophage free-cholesterol (FC) efflux rates, measured as the percent [14C]-cholesterol efflux/6 h, were 8.2±2.3 (n=9) in NAR HDL and 11.2±3.2 (n=10) in SDR HDL (P=0.03). Therefore, in NAR the modification of the HDL composition slows down the cell FC efflux rate, and together with the
increased rate of plasma HDL metabolism influences the reverse cholesterol transport system. 相似文献
6.
Yasuharu Imai Sumio Kawata Masami Inada Shio Miyoshi Yuzo Minami Yuji Matsuzawa Kiyohisa Uchida Seiichiro Tarui 《Lipids》1987,22(7):513-516
Effects of cholestyramine on biliary secretion of cholesterol, phospholipids and bile acids and fecal excretion of sterols
and bile acids were examined in Wistar male rats. Six rats were fed a basal diet, and the other six were fed a basal diet
supplemented with 5% cholestyramine for eight days. Bile flow and biliary secretion of bile acids and phospholipids (per hour
per rat) decreased with cholestyramine treatment, while biliary cholesterol secretion (per hour per rat) remained unchanged.
In the biliary bile acid composition, a marked increase of chenodeoxycholic acid with a concomitant decrease of β-muricholic
acid was observed in cholestyramine-treated rats. Fecal excretion of total sterols and bile acids increased about three-and
four-fold, respectively, after cholestyramine treatment. The increase of fecal bile acids derived from cholic acid was more
predominant than that derived from chenodeoxylcholic acid, resulting in an increase of the cholic acid group/chenodeoxycholic
acid group ratio. 相似文献
7.
Robert Franklin Raicht Dr. Bertram Ira Cohen Bess Eliav Erwin Heinz Mosbach 《Lipids》1978,13(9):605-609
Sterol metabolism studies using isotopic and chromatographic techniques were carried out in: (a) control rats fed stock chow
+0.1% cholesterol (control group), and (b) rats fed stock chow +0.1% cholesterol and supplemented with 0.5% sodium taurodeoxycholate
(taurodeoxycholate group). Feeding the bile acid enriched diet led to decreased acidic steroid synthesis, decreased cholesterol
turnover, and cholesterol balance compared to nonsupplemented controls. There were no significant differences in fecal neutral
sterol output, endogenous neutral sterol output, or cholesterol absorption between bile acid fed animals and controls. Tissue
cholesterol levels (liver, plasma, and bile) in the two groups were also similar. 相似文献
8.
Fatty acid desaturase activities were determined in liver microsomes from calcium-deficient rats and compared to calcium-sufficient
ones. The calcium-deprived diet (0.5 g/kg) administered for 60 d caused a 30% inhibition in the Δ5 desaturase activity and
a 45–55% decrease in Δ6 and Δ9, respectively, facts that cannot be attributed to a reduction in food intake. In vitro addition of calcium, ethyleneglycol-bis(β-aminoethyl ether)N,N-tetraacetic acid, and/or cytosol fractions from control or calcium-deficient rats to microsomes from both groups of animals
indicates that the reduced desaturase capacities would be the consequence of an indirect effect of calcium deprivation. The
present work shows that the reduced unsaturated fatty acid biosynthesis might be the result of modifications in the physicochemical
properties of microsomal membranes. Such changes could also be derived from the inhibition of phospholipase A2 activity induced by calcium deficiency. 相似文献
9.
Sex differences in the effect of ethionine upon rat liver metabolism prompted our investigation into possible sex differences
in the effect of ethionine upon bile acid metabolism. The bile ducts of 24 rats, 12 male and 12 female, were cannulated. After
1 hr of bile collection, 6 rats of each sex were given ethionine, 1 mg/g body wt, by feeding tube. The bile acid composition
of the bile collected during the subsequent 4 hr was analyzed by combined thin layer and gas chromatography. Ethionine induced
a reduction in bile flow (3rd and 4th hr) and in bile acid concentration (4th hr) in female rats. The amino acid had no effect
upon bile flow but did increase biliary secretion of bile acids (1st and 2nd hr) in male rats. Cholic acid accounted for the
bulk of the reduction in total bile acid secretion in the female studies. The increase in total bile acid secretion in the
male studies involved all bile acids. The effects of ethionine upon bile acid secretion were delayed in the female studies,
immediate in the male. The changes in bile acid secretion involved only the taurine conjugates in the female studies, both
taurine and glycine conjugates in the male. There are substantial sex differences in the effect of ethionine upon bile acid
metabolism in the rat. 相似文献
10.
Groups of rats were fed diets containing corn oil, 1% hydrogenated castor oil (principal constituent: 12-hydroxystearic acid)
or 10% hydrogenated castor oil. Rats were sacrificed after 4, 8, 12 and 16 weeks for determination of hydroxy fatty acids
in excised abdominal adipose tissue or in lipid extracted from lyophilized carcass. Maximum content of hydroxystearic acid
was 4.4% in adipose tissue of rats four weeks on the 10% hydrogenated castor oil diet. When rats on hydrogenated castor oil
diets were switched to the corn oil diet, hydroxystearic acid was depleted from their tissues. 10-Hydroxypalmitic and 9-hydroxymyristic
acids were characterized as metabolites of 12-hydroxystearic acid. No adverse effects of diets were observed except reduced
growth in rats given 10% hydrogenated castor oil diet.
Presented at the AOCS Meeting, New York, October, 1968.
Western Utiliz. Res. & Dev. Div., ARS, USDA. 相似文献
11.
The effect of chitosan feeding (for 21 days) on intestinal bile acids was studied in male rats. Serum cholesterol levels in
rats fed a commercial diet low in cholesterol were decreased by chitosan supplementation. Chitosan inhibited the transformation
of cholesterol to coprostanol without causing a qualitative change in fecal excretion of these neutral sterols. Increased
fiber consumption did not increase fecal excretion of bile acids, but caused a marked change in fecal bile acid composition.
Litcholic acid increased sigificantly, deoxycholic acid increased to a leasser extent, whereas hyodeoxycholic acid and the
6β-isomer and 5-epimeric 3α-hydroxy-6-keto-cholanoic acid(s) decreased. The pH in the cecum and colon became elevated by chitosan
feeding which affected the conversion of primary bile acids to secondary bile acids in the large intestine. In the cecum,
chitosan feeding increased the concentration of α-,β-, and ω-muricholic acids, and lithocholic acid. However, the levels of
hyodeoxycholic acid and its 6β-isomer, of monohydroxy-monoketo-cholanoic acids, and of 3α, 6ξ, 7ξ-trihydroxy-cholanoic acid
decreased. The data suggest that chitosan feeding affects the metabolism of intestinal bile acids in rats. 相似文献
12.
The effects of dietary methionine level on the profiles of fatty acids and phospholipids and on the plasma cholesterol concentration
were investigated to confirm whether the methionine content of dietary proteins is one of the major factors that cause differential
effects on lipid metabolism. The effect of dietary supplementation with eritadenine, which is shown to be a potent inhibitor
of phosphatidylethanolamine (PE) N-methylation, was also investigated. Rats were fed six diets containing casein (100 g/kg) and amino acid mixture (86.4 g/kg)
differing in methionine content (2.5, 4.5, and 7.5 g/kg) and without or with eritadenine supplementation (30 mg/kg) for 14
d. The ratio of arachidonic to linoleic acid of liver microsomal and plasma phosphatidylcholine (PC) was significantly increased
as the methionine level of diet was elevated, indicating that dietary methionine stimulates the metabolism of linoleic acid.
The PC/PE ratio of liver microsomes and the plasma cholesterol concentration were also increased by dietary methionine. These
effects of methionine were completely abolished by eritadenine supplementation The S-adenosylmethionine concentration in the liver reflected the methionine level of diet. These results support the idea that
the differential effects of dietary proteins on lipid metabolism might be ascribed, at least in part, to their different methionine
contents, and that methionine might exert its effects through alteration of PE N-methylation. 相似文献
13.
Male and female rats were fed diets containing 2% of calories as corn oil or that plus 40% of calories as beef tallow or corn
oil. After 3, 6, 12 and 18 months groups were given 4-14C-cholesterol ip, and feces were collected for 9 days. Just prior to necropsy3H-acetate was administered ip. Samples of serum, liver, heart and carcass were obtained for analysis. Concentrations of fatty
acids and cholesterol, synthesis of those and recovery of ring-labeled steroid are reported. Mortality from acute respiratory
disease was very high in male rats fed beef tallow or low fat diets and very low in those fed the corn oil diet. In females,
only beef tallow diet resulted in a high mortality rate, and this was lower and at a later age than in males. The most notable
effects of age were in relation to fatty acid synthesis and presence of14C-acidic steroid in the carcass. In 3-month-old rats both fats depressed fatty acid synthesis in comparison to the low fat
diet. At later ages beef fat ceased to depress fatty acid synthesis in both sexes. Corn oil continued to depress fatty acid
synthesis up to 12 months in males and 18 months in females. The presence of14C-acidic steroid in carcass was substantial in 6-month-old rats and constituted ca. 40% of recovered14C in 18-month-old rats. The possibility that the increase in acetate incorporation into fatty acids with age in fat feeding
is related to chain elongation rather than de novo synthesis is discussed. Both the presence and amount of acidic steroid
in the carcass are notable and may be of importance in constructing models of cholesterol turnover.
Presented in part at the AOCS Sterol Symposium, April 1970, and the Federation of American Societies for Experimental Biology,
April 1971.
Scientific Series Paper No. 1536, Colorado Agricultural Experiment Station. 相似文献
14.
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
15.
The aim of the present study was to determine whether increased output of phospholipid in bile during aging may be due to
alteration of bile acid composition and stimulated hydrophobic bile acid formation. In female Sprague-Dawley rats we examined
the influence of aging and life long dietary restriction (60% of thead libitum intake) on bile flow, total bile acid secretion, bile acid composition and conjugation pattern, as well as phospholipid output.
Rats were cannulated at 3.5, 8–12 and 24–27 months of age and bile collected for analysis. With age, there was a significant
reduction in bile flow and total bile acid secretion, however, phospholipid output increased. Restriction of dietary intake
exerted a beneficial effect on the age-related decline in bile formation. Studies of bile composition indicated that 12α-hydroxylated
bile acids (cholic acid and deoxycholic acid) secretion decreased in aged rats compared to 3.5-month-old rats. This was associated
with a corresponding increase in secretion of chenodeoxycholic acid and hyodeoxycholic-ursodeoxycholic acid. However, the
magnitude of the change in secretion of these bile acids could not account for the increased output of phospholipid in bile. 相似文献
16.
This study compared (i) the relative effects of long-chain triglycerides (LCT) and medium-chain triglycerides (MCT), (ii) the influence of amount of MCT, and (iii) the impact of medium-chain fatty acid position, on plasma and lymphatic triglycerides and portal vein free fatty acids. The animals were fed approximately at 250 kcal/kg · day for 20h. The lymph from lymphatic duct and blood from portal vein and systemic circulation were collected. The results showed that feeding 100% MCT for 20h was sufficiently long to reduce significantly the level of linoleic acid in portal vein fatty acids and plasma and lymph triglycerides. However, this alteration induced by MCT feeding was partially prevented by adding LCT to the diet. The level of arachidonic acid was significantly reduced in plasma triglycerides by any of the diets containing medium-chain fatty acids compared to 100% LCT. When feeding MCT only, palmitoleic acid, presumably reflecting de novo lipogenesis, was increased in lymphatic triglycerides and portal vein fatty acids. Total saturated fatty acids as a total percentage of total fatty acids were also significantly increased in plasma and lymphatic triglycerides and portal vein fatty acids. Thus, when linoleic acid is limiting, the conversion of MCT into long-chain fatty acids by de novo lipogenesis is likely to be an important metabolic route. Providing LCT with MCT or 2-monodecanoin appears to limit this pathway. 相似文献
17.
Nozomu Takeuchi Mitsuharu Murase Yasuharu Nomura Haruto Takase Kiyohisa Uchida 《Lipids》1987,22(8):566-571
In order to investigate the effect of hepatic cholesterol flux on biliary bile acids, Triton WR 1339 and orotic acid were
administered to rats, and the biliary cholesterol, phospholipids and bile acids were analyzed together with serum lipoproteins
and hepatic lipids. Triton, which raised serum very low density lipoprotein and lipid levels and decreased serum high density
lipoprotein liver lipid levels, increase the biliary cholic acid group/chenodeoxycholic acid group ratio (CA/CDCA) in the
bile without affecting the total amount of bile acids and the other biliary lipids. Orotic acid, which decreased serum lipid
and lipoprotein concentrations and increased liver lipid levels, increased the biliary excretion of cholesterol and phospholipids,
but produced no significant change in the total amount of bile acids and in the CA/CDCA ratio in bile. 相似文献
18.
Shigeru Hashimoto Hirotsune Igimi Kiyohisa Uchida Takashi Satoh Yoshimi Benno Nozomu Takeuchi 《Lipids》1996,31(6):601-609
Wistar male rats were treated for six days with broad spectrum β-lactam antibiotics, latamoxef, and cefotaxime. On the seventh
day, the number of fecal anaerobic microbes decreased, total fecal bile acids decreased, and bile acid pools increased. Secondary
bile acids such as β-hyocholic, hyodeoxycholic, lithocholic, and deoxycholic acids decreased in the feces while the primary
bile acids, cholic, β-muricholic, and chenodeoxycholic acids, became predominant. Coprostanol, a microbial metabolite of cholesterol,
also disappeared from the feces during the treatment. The cecum enlarged to almost twice the size of that in control rats,
whereas the liver weight was not significantly changed. After treatment was stopped, the number of fecal microbes returned
to the initial counts within a week, but restoration of bile acid and cholesterol metabolism required at least three weeks. 相似文献
19.
Correlation of suppressed linoleic acid metabolism with the hypocholesterolemic action of eritadenine in rats 总被引:1,自引:0,他引:1
The dose-dependent effects of dietary eritadenine on the metabolism of linoleic acid and on the plasma cholesterol concentration
were investigated to clarify the mechanism of the hypocholesterolemic action of eritadenine in rats. Rats were fed control
or eritadenine-supplemented (2 to 20 mg/kg) diets for 14 d. Eritadenine supplementation significantly decreased both the plasma
cholesterol concentration and the 20∶4n−6/18∶2n−6 ratio of liver microsomal and plasma phosphatidylcholine (PC) in a dose-dependent
manner. Eritadenine was also found to decrease the activity of Δ6 desaturase in liver microsomes; these was significant correlation
between the Δ6-desaturase activity and the 20∶4n−6/18∶2n−6 ratio in the PC of liver microsomes (r=0.989, P<0.001) or plasma (r=0.986, P<0.001). Certain plasma PC molecular species, as represented by 16:0-18:2, were increased by eritadenine in a dose-dependent
manner, and certain plasma PC molecular species, as represented by 18:0-20:4, were conversely decreased by eritadenine. There
was a significant correlation between the plasma total cholesterol concentration and the proportion of the sum of plasma PC
molecular species which contain 18:1 or 18:2 in the sn-2 position. These results support the idea that the suppression of linoleic acid metabolism by eritadenine might be associated
with the hypocholesterolemic action of eritadenine. 相似文献
20.
Kyoichi Osada Takehiro Kodama Koji Yamada Shingo Nakamura Michihiro Sugano 《Lipids》1998,33(8):757-764
The interactive effect of high dietary levels of oxidized cholesterol on exogenous cholerterol and linoleic acid metabolism
was examined in male 4-wk-old Sprague-Dawley rats given high-cholesterol diets. The rats were pair-fed purified diets free
of or containing either 0.5% cholesterol alone or both 0.5% cholesterol and 0.5% oxidized cholesterol mixture (containing
93% oxidized cholesterol) for 3 wk. Hepatic 3-hydroxy-3-methylglutaryl CoA reductase activity was reduced in rats given cholesterol
alone or both cholesterol and oxidized cholesterol. However, hepatic cholesterol 7α-hydroxylase activity was lowered only
when rats were given both cholesterol and oxidized cholesterol, although dietary cholesterol increased this activity. Reflecting
this effect, acidic steroid excretion was lowest among the groups of rats given cholesterol and oxidized cholesterol. On the
other hand, the activity of hepatic Δ6 desaturase, a key enzyme in the metabolism of linoleic acid to arachidonic acid, was
increased in rats given both cholesterol and oxidized cholesterol, although dietary cholesterol alone lowered its activity.
As a result, the Δ6 desaturation index, 20∶3n-6+20∶4n-6/18∶2n-6, in liver and serum phosphlipids tended to be higher in the
group fed both cholesterol and oxidized cholesterol than in the one fed cholesterol alone. Thus, dietary oxidized cholesterol
significantly modulated exogenous cholesterol metabolism and promoted linoleic acid desaturation even when it was given at
high levels together with a high cholesterol diet. 相似文献