Glucuronidated and sulfated bile acids in serum of patients with acute hepatitis

The concentrations of glucuronidated and sulfated bile acids in the serum of 15 patients with acute hepatitis were determined by mass fragmentography. Total serum bile acid levels were 13.79-444.10 mumol/liter, and the percentages of glucuronidated and sulfated bile acids were in the wide ranges of 1.7-33% and 2.4-49%, respectively. In four of the five patients for whom serum bile acids were analyzed serially from the acute to the recovery stages of acute hepatitis, the decrease of the glucuronidated and sulfated bile acids was slower than that of nonglucuronidated, nonsulfated bile acids. Thus, the relative proportion of the glucuronides and sulfates in total bile acids apparently increased during the recovery phase. The mechanism for the relative predominance of bile acid esters in serum during recovery is unknown but might reflect an improved excretion of the nonesterified bile acids into bile after the rapid recovery of intrahepatic cholestasis.

Stereochemistry of 2,3-alkanediols obtained from the Harderian gland of Mongolian gerbil (Meriones unguiculatus)

The stereochemistry of the alcohol moieties of 2,3-alkanediol diacyl esters obtained from the Harderian gland of the Mongolian gerbil was investigated. There were five major 2,3-alkanediols, C14-C22 (even carbon numbers), all having the erythro configuration as determined by GC-MS analysis of their isopropylidene derivatives in comparison with synthetic erythro- and threo-2,3-hexadecanediols. 13C-NMR spectroscopy of the synthetic materials showed distinct differences of chemical shift at the C-1, C-3, and C-4 carbons, from which the native 2,3-alkanediols were definitely determined to be in the erythro series. The absolute configurations of the C-2 and C-3 asymmetric centers were assigned as 2S and 3R, respectively, based on known 2S,3R-octanediol.

Biochemical diagnosis of cerebrotendinous xanthomatosis using reversed phase thin layer chromatography

We developed a simple quantitative procedure for cholestanol in serum involving reversed phase thin layer chromatography. This procedure was satisfactory with regard to the linearity of the calibration curve in the range of 100 ng to 1,000 ng, recovery and reproducibility. Only 100 microliter of serum was needed for determination of the cholestanol concentration. Prior to thin layer chromatography, cholesterol was converted to alpha- and beta-epoxides with m-chloroperbenzoic acid, which were clearly distinguishable from cholestanol on TLC. Detection of sterols was performed by spraying with phosphomolybdic acid solution. Quantification of cholestanol was carried out with a TLC scanning densitometer. When serum cholestanol in cerebrotendinous xanthomatosis (CTX) patients was quantified by TLC, GC-MS, and GC, the correlation among the three methods was found to be approximately 1:1:1. It was found that the present method was useful for the primary diagnostic screening of CTX because of its simplicity and because many samples could be analyzed at one time.

Tissue distribution of leukotriene A4 hydrolase activity in guinea pig

The distribution of the activity of leukotriene A4 hydrolase, an enzyme catalyzing hydrolysis of the allylic epoxide leukotriene A4 to the dihydroxy acid leukotriene B4, was determined in various tissues of guinea pig by using the supernatant fraction (100,000 X g, 60 min) of the homogenates. The activity was ubiquitously distributed in all tissues examined, and the highest specific activity was found in small intestine, followed by lung, aorta, colon, and spleen, in this order. The specific activity in these tissues was higher than that of leukocytes. The physiological roles of this compound in these organs deserve reexamination in this context.

[Comparison of experimental diabetes induced by streptozotocin and cyproheptadine]

It is generally accepted that Diabetes mellitus is caused by the endocrinological functional disturbance of the pancreas, decreasing available insulin for carbohydrate metabolisms. Diabetes mellitus is not necessarily related to hypoinsulinemia, and some senile subjects show diabetic symptoms although the insulin levels in their blood are within the normal range. Therefore, in order to examine the cause of Diabetes mellitus, the glucose tolerance test is usually given as a routine laboratory method to monitor the pancreatic endocrine functions. The pattern of decreasing glucose level in blood will tell us what is the cause of the disease. In testing the effects of anti-diabetic drugs, experimental diabetic conditions have been prepared by various methods, and recently streptozotocin (STZ) and cyproheptadine (CPH) have been successfully used to induce diabetic conditions of various degrees. In the present study, degree of disturbance of the pancreatic functions by STZ and CPH were compared, and in addition, disturbance of organs other than the pancreas was also examined biochemically. When a high dose of STZ was given, irreversible disfunction of glucose level normalizing and insulin secreting abilities was observed. Serum GOT, GPT, lysosomal enzyme activities and lysosomal enzyme activity in the liver and pancreas decreased in high dose STZ administered rats. Low dose STZ disturbed the pancreatic endocrine function less than that in high dose STZ, and the blood glucose level normalizing function was reversibly disturbed. Insulin secretion decreased, and normalized on discontinuation of low dose STZ administration. Low dose STZ also disturbed organs other than the pancreas as in high dose STZ.(ABSTRACT TRUNCATED AT 250 WORDS)

[Stimulation of pituitary-adrenocortical system by cepharanthine]

We observed that cepharanthine might exert its anti-allergic action by stimulating the secretion of corticosterone. The present experiments were carried out to investigate stimulation of the pituitary-adrenocortical system by cepharanthine. Administration of cepharanthine to rats produced increases in plasma and adrenal corticosterone levels. Administration of cepharanthine to propranolol pretreated rats also produced increases in plasma and adrenal corticosterone levels and plasma ACTH level. The elevation of corticosterone level induced by cepharanthine was considered to be the specific effect of cepharanthine. Cepharanthine did not increase plasma corticosterone level in rats in the state of dexamethasone suppression of the pituitary-adrenocortical system, in which the level was lowered. Administration of cepharanthine to Bordetella pertussis vaccine induced beta-adrenergic blocked rats also produced increases in plasma and adrenal corticosterone levels. The production and release of corticosterone from an adrenal cell suspension were not influenced by cepharanthine in vitro. These results suggest that cepharanthine stimulates the pituitary-adrenotropic function.

A simultaneous quantitation of leukotriene B4 and its omega-oxidized products by gas chromatography-mass spectrometry

We developed a highly sensitive and specific method for the simultaneous quantitation of leukotriene B4 (LTB4) and its omega-oxidized metabolites (20-hydroxy-LTB4 and 20-carboxy-LTB4) by mass fragmentography using deuterated compounds as internal standards. The ions produced by the cleavage of the C12-13 bond of the methyl ester dimethylisopropylsilyl ether derivatives of LTB4 and its metabolites were measured by selective ion monitorings. The detection limit of LTB4 was less than 10 pg and about 100-fold lower than that by high performance liquid chromatography. By using this method, the synthesis and further metabolism of LTB4 in human polymorphonuclear leukocytes were investigated.

Specific determination of arylsulfatase A activity

Arylsulfatase activities in biological materials are too low to be detected by the methods available hitherto. A sensitive and specific assay method for arylsulfatase A (AS-A) has been developed in the present study. Ascorbate-2-sulfate is known to be a specific natural substrate of AS-A; the ascorbic acid liberated by the action of AS-A was quantitatively determined using HPLC equipped with an amperometric detector. The method was used to analyze the activity of AS-A in biological materials.

Evidence that arachidonic acid is deficient in phosphatidylinositol of Drosophila heads

We have found that arachidonic (20 : 4) acid is indetectable in phosphatidylinositol and diacyglycerol extracted from Drosophila heads. After careful examinations of the lipid extraction processes and fatty acid detection system (gas-liquid chromatography), we excluded the possibility of the oxidation of polyunsaturated fatty acids or of having overlooked a trace amount of the fatty acid. The precursors of arachidonic, dihomo gamma-linolenic (20 : 3), and gamma-linolenic (18 : 3) acid, were also indetectable in these lipids. On the basis of these results, it appears that the arachidonic acid cascade is essentially absent in Drosophila head, including the brain and compound eyes. Since arachidonic acid is considered to be a key molecule in phosphatidylinositol turnover in the brain, it is of interest that Drosophila brain and eyes do not require arachidonic acid for their functions.

Determination of 3 beta-hydroxy-5-cholenoic acid in serum of hepatobiliary diseases--its glucuronidated and sulfated conjugates

3 beta-Hydroxy-5-cholenoic acid in the serum of control subjects and 62 patients with various hepatobiliary diseases was quantitated by mass fragmentography after separation into nonglucuronidated-nonsulfated, glucuronidated, and sulfated fractions. Deuterium-labeled deoxycholic acid and its glucuronide and sulfate were used as internal standards. Mean concentrations of total 3 beta-hydroxy-5-cholenoic acid in serum (mumole/liter) were as follows: Control subjects (14), 0.184; obstructive jaundice (15), 6.783; liver cirrhosis, compensated (12), 0.433, and decompensated (12), 1.636; chronic hepatitis (12), 0.241; and acute hepatitis (11), 2.364. Most of the 3 beta-hydroxy-5-cholenoic acid was glucuronidated or sulfated. Only in patients with obstructive jaundice did glucuronidation (60 +/- 14%) exceed sulfation (31 +/- 14%), sulfation exceeding glucuronidation in the others. The UDP-glucuronyltransferase might have different substrate specificities for 3 beta-hydroxy-5-cholenoic acid and other common bile acids, especially in the cholestatic state.

Serum concentrations of glucuronidated and sulfated bile acids in children with cholestasis

Serum concentrations of nonglucuronidated-nonsulfated, glucuronidated, and sulfated bile acids in 9 control children and 16 children with cholestasis were quantitated by mass fragmentography. Total bile acid levels in control children were 19.55 +/- 2.78 mumol/liter (mean +/- SEM), and glucuronidated and sulfated bile acids comprised 2.6 +/- 0.5 and 17 +/- 3.1%, respectively. In 9 patients with congenital biliary atrasia, total bile acid levels were 167.34 +/- 11.18 mumole/liter of which 2.1 +/- 0.3% were glucuronidated and 15 +/- 1.4% were sulfated. Lithocholic and 3 beta-hydroxy-5-cholenoic acids, which have hepatotoxic effects, were presented in only small amounts in cholestatic children, and they were almost all glucuronidated or sulfated. The percentages of glucuronidated bile acids in control and cholestatic children were lower than in healthy and cholestatic adults, which may be explained by the lower activity of UDP-glucuronyltransferase in neonatal liver.

Assay of fatty acid synthetase by mass fragmentography using [13C]malonyl-CoA

A new assay method for fatty acid synthetase using mass fragmentography was described. [2-13C]Malonyl-CoA was chemically synthesized from [2-13C]malonic acid and used as a substrate. The newly synthesized fatty acids were quantitated with a GC-MS instrument after methyl esterification. Monitoring of molecular ions of the newly synthesized fatty acids enabled us to determine the absolute amounts with heptadecanoic acid as an internal standard. Multiple products (14 : 0, 16 : 0, and 18 : 0) were measured individually. Using this technique, we obtained information about production profiles such as that of chain length against incubation temperature and about malonyl-CoA decarboxylation activity in enzyme preparations, and we also confirmed the presence of malonyl-CoA decarboxylation activity even in purified fatty acid synthetase from guinea pig Harderian gland. Compared with the conventional assay methods (spectrophotometric and radioisotopic), this method was more reliable and useful.

The quaternary structure and activity of newly purified fatty acid synthetase from the Harderian gland of guinea-pig

Fatty acid synthetase was isolated from the Harderian gland of guinea-pig. The fatty acids synthesized by the purified enzyme were analyzed by mass fragmentography. The purified enzyme had an inherent capacity to utilize methylmalonyl-CoA and synthesize methyl-branched fatty acids. Physicochemical studies indicated that an active enzyme was a dimer, consisted of two subunits of Mr = 2.5 X 10(5). The negatively stained enzyme had an electron micrographic image of an ellipsoidal contour with a continuous middle cleft along the major axis. The major and minor axes were approximately equal to 220 and 150 A, respectively. In a dimer, the subunit had a rod-like structure about 220 A long and 50 A wide. The enzyme was inactivated and dissociated into subunits by incubation at 0 degree C. The inactivated enzyme was fully reactivated by raising the temperature of the solution. The relationship between the quaternary structure of the enzyme and the occurrence of enzymatic activity was studied by high-performance liquid chromatography. Neither active monomers nor inactive dimers were found in inactivation and reactivation processes. The initial velocity of reactivation was proportional to the enzyme concentration over a concentration range of 160-800 micrograms/ml, indicating that the rate-determining step in the reactivation reaction was unimolecular.

[Changes of lysosomal enzyme activities in experimental type I and type IV allergic models]

Experimental allergy was induced in animals: asthma, a Type I allergy, was induced in guinea pigs by sensitizing them with alpha-amylase (inhalation), and experimental allergic encephalomyelitis (EAE), a Type IV allergy, was induced in rats. Pulmonary, brain and serum lysosomal enzyme activities were measured in normal and allergic conditions. beta-Glucuronidase (beta-G) and arylsulfatase (AS) activities were determined by the fluorescent technique. During the asthmatic attack, pulmonary lysosomal enzyme activities were not different from that in the normal state in guinea pigs. However, brain lysosomal enzyme activities were elevated markedly on the 1 st day of EAE induction. Brain beta-G activity was elevated on the 2nd day, and AS activity had a tendency to be increased. On the other hand, serum lysosomal enzyme activity was not altered significantly. In the experimental allergy, lysosomal enzyme activity was altered in Type IV, but not in Type I.

Profiles of bile acids and their glucuronide and sulphate conjugates in the serum, urine and bile from patients undergoing bile drainage

Bile acid profiles in serum, urine, and bile from patients undergoing bile drainage and the changes of serum bile acids after bile drainage were studied. Bile acids were separated into non-glucuronidate-non-sulphate, glucuronidated, and sulphated fractions and were measured by mass fragmentography using conjugates of deuterium labelled bile acids as internal standards. Glucuronidated and sulphated bile acids contribute 14-32% and 16-44% of serum bile acids, 4-11% and 61-82% of urine bile acids and 0.2-1% and 0.3-2% of biliary bile acids respectively. After bile drainage the concentration of serum non-glucuronidated-non-sulphated bile acids decreased more rapidly than glucuronidated and sulphated bile acids. There was little biliary excretion of the glucuronidated and sulphated bile acids. Such conjugation appears to have a role in facilitating bile acid excretion by the urinary route.

Bile acid profiles in analbuminemia rats

Bile acid profiles in serum, urine and bile of Nagase analbuminemia rats (NAR) and Sprague-Dawley rats (SDR) were examined. Serum bile acid levels in NAR (2.02 + 0.51 micrograms/ml, n = 15, M +/- S.E.) were markedly decreased as compared with those in SDR (20.86 +/- 3.72 micrograms/ml, n = 10). The unbound fraction of acids in serum examined by equilibrium dialysis was about ten times higher in NAR than in SDR. In the profiles of urinary and biliary bile acids in NAR and SDR, as big differences as seen for serum bile acids were not observed. Low bile acid levels in serum of NAR may reflect low bile acid binding capacity of NAR serum because the absence of albumin was thought to be one of the major causes of low bile acid levels in serum of NAR.

Cytotoxic factor production by Kupffer cells elicited with Lactobacillus casei and Corynebacterium parvum

The ability of Kupffer cells, spleen macrophages, pulmonary macrophages, and peritoneal macrophages (PM) to produce cytotoxic factor (CTF) was investigated in vitro. The production of CTF by Kupffer cells elicited with Corynebacterium parvum (CP) or Lactobacillus casei YIT9018 (LC9018) was higher than that of spleen, pulmonary macrophages, or PM. In addition, oxygen radical (OR) production by Kupffer cells or PM was measured. The production of OR by Kupffer cells or PM was significantly augmented by i.v. or i.p. injection of LC9018 or CP. No significant correlation was observed between the increase in OR production by Kupffer cells or PM and CTF production by Kupffer cells or PM elicited with either organism. It was suggested that activated Kupffer cells may be one important source of CTF production in serum and that the CTF-producing macrophages may be different from the OR-producing macrophages.

Fatty acid composition of cardiolipin from guinea pig Harderian gland

The fatty acid composition of cardiolipin from the Harderian gland of guinea pig was examined by gas chromatography and gas chromatography-mass spectrometry. At least 33 kinds of fatty acids were detected. Oleic acid was the most prominent component, accounting for 18.2 mol% of the total fatty acids. About 70.2 mol% of fatty acids had methyl branches. Ethyl branches were also detected (1.3 mol%). Straight chain saturated acids comprised only 10.3 mol%. On the other hand, linoleic, linolenic, and arachidonic acids were not found in this lipid. The 2-(2'-) acyl moieties contained larger amounts of oleic acid and smaller amounts of branched chain acids than the 1-(1'-)acyl moieties, but the saturated straight chain acids showed even distribution between the 1-(1'-) and 2-(2'-)positions. The fatty acids of cardiolipin from the liver of the same animal were also examined. Linoleic acid was the most abundant component (66.9 mol%), and saturated straight chain acids occupied 21.9 mol%. Branched chain acids were detected but comprised only 11.2 mol%.

[Anti-hyperlipidemic effect of iodine eggs: studies on the mechanism of its action]

The anti-hyperlipidemic effect of the iodine egg was found to be in the neutral lipid (NL) fraction in its yolk. For the purpose of clarifying the hypolipidemic effect of the iodine-containing NL fraction, the effect of clofibrate (CPIB) was investigated. CPIB was found to lower TC, atherogenic index [(TC-HDL cholesterol)/HDL cholesterol], TG and FFA, but not FC; while NL lowered TC, FC and the atherogenic index, but not TG and FFA. Cholesterol metabolites, probably metabolized in the liver, were examined. Hepatic cholesterol level was increased by NL and CPIB. The ratio of fecal bile acid of the excretion type, lithocholic acid (LCA) to deoxycholic acid (DCA), increased when NL and CPIB were administered, but the hepatic HMG-CoA reductase activity, responsible for the endogenous cholesterol synthesis, was not altered. Thus, the anti-hyperlipidemic mechanism of NL may be the mobilization of peripheral cholesterol to the liver, probably for the disposal by excretion as bile acids.

Urinary concentrations of bile acid glucuronides and sulfates in hepatobiliary diseases

Urinary bile acids in normal subjects and patients with obstructive jaundice and liver cirrhosis were quantitated by mass fragmentography after separation into nonglucuronidated-nonsulfated, glucuronidated and sulfated fractions. Mean values of total bile acids in urine were as follows: Control subjects (n = 7), 1.90 +/- 0.67; obstructive jaundice (n = 9), 77.90 +/- 40.39; liver cirrhosis, compensated (n = 6), 15.14 +/- 8.97, and decompensated (n = 6), 11.84 +/- 9.32 (mean +/- SD, mg/day). The percentages of each conjugate was 19-29% in the non-glucuronidated-nonsulfated fraction, 6-14% in the glucuronidated fraction and 60-74% in the sulfated fraction. Bile acids in urine and serum correlated well in each fraction (r = 0.82-0.84, p less than 0.001). The clearance of the three conjugates was the highest in the sulfates, and the clearance of glucuronides was higher than that of non-esterified bile acids. The glucuronidation and sulfation of bile acids play an important role in the detoxication of bile acids by excreting them into urine, especially in patients with elevated serum bile acids.

[Antihyperlipidemic effect of iodine egg: search for active ingredients and their iodine contents]

Active fractions that possess the hypocholesterolemic effect of iodine egg yolk lipid fraction have been investigated with male Wistar strain rats fed on a cholesterol-rich diet. Iodine egg yolk lipid was extracted by Folch's (chloroform: methanol) method and was refractionated into a neutral lipid (IEY-NL) fraction and a polar lipid (IEY-PL) fraction. The iodine content in each fraction was determined. The animals were kept on the cholesterol-rich diet for 5 days, and then they were fed the fractions in addition to the above diet for 10 more days. The hypocholesterolemic effect was seen most significantly with the IEY-NL fraction. The serum total cholesterol level in rats receiving this fraction was 70% as compared with that of the Ch group (fed on the cholesterol diet). However, the liver total cholesterol level was not affected or rather increased by the IEY-NL fraction. Another fraction (IEY-PL) showed no such effect. Iodine content in the IEY-NL fraction was quite low (0.2 ppm) compared with the other fractions. The daily dose in terms of iodine in the IEY-NL fraction was only the amount equivalent to 1/50 of the reported daily requirement for the rat. The IEY-NL fraction induced the hypocholesterolemic effect, though it contained only a trace of iodine.

[Antihyperlipidemic effect of iodine egg: Search for the screening method and active ingredients]

A screening method for the hypolipidemic effect of iodine egg and its active fractions have been investigated with Wistar strain male rats fed on a cholesterol-rich diet. The animals were kept on the cholesterol-rich diet for 5 days, and then iodine egg was fed to them in addition to the above diet for 10 more days. The present method was the most adequate for screening the hypolipidemic effect. Iodine egg yolk was fractionated into the following 3 fractions by Folch's method: Protein ( IEY -P), water-soluble ( IEY -A) and lipid ( IEY -L) fractions. The hypolipidemic effect of these fractions was determined with the screening method. The marked hypolipidemic effect was induced by the IEY -L fraction. The serum total cholesterol level in rats that received the fraction was 57% as compared with that of the ch group (fed on the cholesterol-rich diet). The other groups showed no such effect. Serum thyroid hormone levels were not affected by the IEY -L fraction which was found to be the active hypolipidemic fraction of iodine egg. The thyroid gland did not seem to participate directly in such a hypolipidemic effect.

The characterization of 2,3-alkanediol diacyl esters obtained from the Harderian glands of Mongolian gerbil (Meriones unguiculatus)

A major lipid class in the Harderian glands of the Mongolian gerbil was investigated. The IR and 1H-NMR spectra suggested that it was a wax-like compound. Fatty acids present were capric, lauric, myristic, palmitic, stearic, arachidic, and behenic acids in ratios of 3.0%, 16.3%, 16.5%, 29.5%, 5.1%, 16.4%, and 9.8%, respectively. Odd-numbered, branched chain and unsaturated fatty acids were not present in large amounts. The structure of the alcohol moiety was elucidated to be 2,3-alkanediol with carbon chain lengths from C12 to C22 by GC-MS of the TMS and isopropylidine derivatives. Lemieux-von Rudloff oxidation of these alcohols confirmed the 2,3-diol structure, giving fatty acids two carbon units shorter.

Determination of sulfated and nonsulfated bile acids in serum by mass fragmentography

A Sep-Pak C18 cartridge was used for purification of bile acids from serum. Three kinds of deuterium labeled internal standards were required for accurate measurement of individual sulfated and nonsulfated bile acids. These internal standards were added to the serum before its application to the cartridge. Separation of sulfated and nonsulfated bile acids was performed on piperidinohydroxypropyl Sephadex LH-20 column chromatography. The nonsulfate fraction was submitted to alkaline hydrolysis, and the sulfate fraction to solvolysis followed by alkaline hydrolysis. Each fraction was converted to the hexafluoroisopropyl-trifluoroacetyl derivatives and quantitated by mass fragmentography. The recovery of each bile acid sulfate was quite satisfactory. In fasting healthy subjects the mean of total nonsulfated bile acids in serum was 1.324 micrograms/ml, and that of total sulfated bile acids was 0.450 micrograms/ml. Sulfated lithocholic acid comprised a large part of sulfated bile acids in healthy subjects.

Branched chain fatty acids in phospholipids of guinea pig Harderian gland

Fatty acid compositions of phosphatidyl ethanolamine and phosphatidyl choline extracted from the guinea pig Harderian gland were examined by gas chromatography and gas chromatography-mass spectrometry. Oleic acid was the major component of both phospholipids, but a large amount of saturated branched chain fatty acids was found: 34.5% in phosphatidyl ethanolamine, and 42.9% in phosphatidyl choline. On the other hand, linolenic and arachidonic acids were not found in these phospholipids. At the 1-position of phosphatidyl choline and phosphatidyl ethanolamine, 54.3% and 40.9% of fatty acids, respectively, had methyl branches. These methyl branches were located at the even-numbered carbon atoms. Branched chain fatty acids were also found at the 2-position of both lipids: 36.2% in phosphatidyl choline and 31.2% in phosphatidyl ethanolamine. The fatty acids of phosphatidyl ethanolamine and phosphatidyl choline from liver, cerebrum, cerebellum, erythrocytes, and plasma of the same animal were also analyzed. Saturated and unsaturated fatty acids, including arachidonic acid, were the major components. Branched chain fatty acids were also found in these lipids, but in very small amounts.

Quantitative determination of non-sulfated bile acids in the serum of patients with hepatobiliary diseases by mass fragmentography

Individual non-sulfated bile acids in the serum of 65 patients with hepatobiliary diseases were quantitated by mass fragmentography. Serum with deuterium labeled deoxycholic acid as an internal standard was hydrolyzed with strong alkali, extracted with ether after acidification under cooling, and quantitated by mass fragmentography as the hexafluoroisopropyl-trifluoracetyl derivatives. In obstructive jaundice, the ratio of cholic to chenodeoxycholic acid was significantly higher than others. Cholic or chenodeoxycholic acid levels were correlated with total bilirubin levels in obstructive jaundice and acute hepatitis. Lithocholic acid value was independent of the degree of liver injury. Total bile acid value was helpful in estimating the extent of liver cell injury and cholestasis, and these two pathological conditions can be distinguished to some extent by cholic to chenodeoxychoic acid ratio.

Serum concentrations of bile acid glucuronides in hepatobiliary diseases

Bile acid glucuronides in the serum in various hepatobiliary diseases (36 cases) were quantitated by mass fragmentography and their clinical significance was discussed. Serum was added to defined amounts of deuterium-labeled bile acids and their glucuronide and sulfate derivatives, and the bile acids were separated into unconjugated, glucuronidated and sulfated groups after enzymatic cleavage of amide bonds. The liberated bile acids were quantitated by mass fragmentography. Bile acid glucuronides comprised about 7-8% of the total bile acids in the serum of various patients. Chenodeoxycholic acid was the major glucuronidated bile acid while cholic acid was mostly unconjugated. Lithocholic acid was almost all either sulfated or glucuronidated. In patients with obstructive jaundice, glucuronidated bile acids also comprised about 5%, although their absolute amounts were increased. In patients with liver cirrhosis, bile acid glucuronides were decreased, especially in decompensated cases, possibly as a result of hepatocellular dysfunction.

Studies on the biosynthesis of cholestanol in cultured cells

The presence of cholestanol had never been reported in cultured cells, but in the present study cholestanol was detected both in human and rat skin fibroblasts. The present study has shown that the origin of cholestanol in these fibroblasts was derived from de novo synthesis in the cells rather than from the fetal calf serum used in the growth medium. The activity of 5 alpha-cholestan-3-one reductase which is the enzyme catalyzing the final step in the biosynthesis of cholestanol was measured by mass fragmentography using deuterium labeled 5 alpha-cholestan-3-one as a substrate. The activity of this enzyme was also detected in the microsomal fractions of rat cerebrum and cerebellum as well as in the liver. These results suggest that cholestanol can probably be synthesized in extra-hepatic tissues as well as in the liver.

Quantitative determination of bile acid glucuronides in serum by mass fragmentography

Individual non-glucuronidated . non-sulfated, glucuronidated and sulfated bile acids in serum were determined, i.e. lithocholic acid, deoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid, and cholic acid, by mass fragmentography. Glucuronic acid conjugates of lithocholic acid, deoxycholic acid, chenodeoxycholic acid, and cholic acid were synthesized via the Koenigs-Knorr condensation reaction. Deuterium labeled deoxycholic acid, lithocholic acid glucuronide, deoxycholic acid glucuronide, and deoxycholic acid sulfate were synthesized and used as internal standards. A serum sample of 1 ml including internal standards was purified with a Sep-Pak C18 cartridge. After the enzymatic cleavage of amino acid conjugates, bile acids were separated into three fractions, free, glucuronidated, and sulfated bile acids, using piperidinohydroxypropyl Sephadex LH-20 (Goto et al. (1978) Clin. Chim. Acta 87). Glucuronidated and sulfated bile acids were deconjugated by beta-glucuronidase treatment and solvolysis. Each fraction was converted to the hexafluoroisopropyl-trifluoroacetyl derivative and quantitated by mass fragmentography. The average concentrations of individual bile acid glucuronides from healthy fasting subjects (n = 9) were as follows; lithocholic acid 0.013 microgram/ml, deoxycholic acid 0.083 microgram/ml, chenodeoxycholic acid 0.078 microgram/ml, ursodeoxycholic acid 0.013 microgram/ml, and cholic acid 0.007 microgram/ml. Bile acid glucuronides occupied 7.8% of the total bile acids.

A case of cerebrotendinous xanthomatosis: effects of ursodeoxycholic acid administration on serum bile acids and cholestanol

Cerebrotendinous xanthomatosis (CTX) is a rare familiar disease characterized by tendon xanthomas, cataracts, cerebellar ataxia, dementia and an elevated serum cholestanol level. In this paper, a 50-year-old man with typical signs and symptoms of CTX is described. Serum cholestanol and chelesterol concentrations were 17.9-28.6 micrograms/ml and 109-153 mg/dl, respectively. The determination of non-sulfated bile acid concentration in the serum assayed by mass fragmentography disclosed an abnormal profile. The concentration of cholic acid (0.30-0.52 microgram/ml) was higher than normal, while those of chenodeoxycholic acid, ursodeoxycholic acid, deoxycholic acid and lithocholic acid were extremely low or undetectable. Administration of ursodeoxycholic acid (300 mg per day, orally) for 2 weeks resulted in a marked reduction of serum cholic acid concentration. However, serum cholestanol levels remained unchanged.

Serum bile acid profiles in cerebrotendinous xanthomatosis

Non-sulfated bile acid concentrations in sera of 10 cases of cerebrotendinous xanthomatosis (CTX) were determined by mass fragmentography. Total bile acid (TBA) in serum was 0.492 +/- 0.436 microgram/ml (mean +/- SD) which was significantly lower than that (1.481 +/- 0.571) in healthy control sera. Cholic acid was 0.342 +/- 0.291 microgram/ml and was the dominant bile acid, which constituted 69.5% of TBA in serum. Chenodeoxycholic acid was 0.111 +/- 0.133 microgram/ml being a minor component in CTX sera, although it was the major bile acid in healthy control sera. Other bile acids such as deoxycholic acid, lithocholic acid and ursodeoxycholic acid were scarcely detected. Subnormal TBA level and deranged bile acid composition in CTX sera may reflect the defect of bile acid biosynthesis in CTX patients. Determination of serum bile acid may be useful in the diagnosis of CTX.

Propionyl-Coa induced synthesis of even-chain-length fatty acids by fatty acid synthetase from Brevibacterium ammoniagenes

The product distribution of Brevibacterium ammoniagenes fatty acid synthetase has been investigated using propionyl-CoA instead of acetyl-CoA as the primer. The synthetase produces not only an odd-numbered fatty acid (heptadecanoic acid) but also even-numbered fatty acids (stearic and oleic acids) in the presence of propionyl-CoA. The amounts of heptadecanoic, stearic and oleic acids increased with increasing concentration of propionyl-CoA. However, the formation of heptadecenoic acid (C17:1) was not observed under any conditions tested. The failure of C17:1 synthesis suggested that the enzyme component catalyzing the beta, gamma-dehydration, which is responsible for the synthesis of unsaturated fatty acids, has a high degree of chain length specificity. Under standard assay conditions, stearic acid predominated and heptadecanoic and oleic acids were found in lesser amounts. Mass spectrometric analyses of fatty acids synthesized either from [2H]propionyl-CoA or in 2H2O revealed that propionyl-CoA is utilized as the priming substrate for the synthesis of heptadecanoic acid and that an acetyl residues, which is formed by the decarboxylation of malonyl-CoA, served as the priming substrate for the syntheses of stearic and oleic acids. No evidence was obtained for the direct decarboxylation of malonyl-CoA to acetyl-CoA in this reaction. It is concluded that the decarboxylation of the malonyl moiety bound to the synthetase occurs efficiently only in the course of fatty acid synthesis. A hypothetical scheme is presented to explain the propionyl-CoA-dependent decarboxylation of the malonyl moiety.

Steric course of deuterium incorporation from [2-2H2]malonyl-CoA into fatty acids by fatty acid synthetases

The steric course of the enoyl reduction catalyzed by fatty acid synthetase was investigated with the enzymes from bakers' yeast, rat liver and Brevibacterium ammoniagenes. The non-enzymic hydrogen-deuterium exchange of the methylene group of malonyl-CoA was studied by NMR spectroscopy. The half-life period of the methylene protons was 4.8 min at 37 degrees C and 12.2 min at 23 degrees C at p2H 7.5. Deuterium-labeled fatty acids were synthesized by incubating the synthetases with [2-2H2]malonyl-CoA for 8 min. The deuterium-labeled fatty acids thus produced were extracted and subjected to the action of acyl-CoA oxidase, which had been previously shown to catalyze the anti elimination of the pro-2R and pro-3R hydrogens of acyl-CoA. The resulting products, 2,3-dehydroacyl-CoAs, were methylated and converted to 3-chlorofatty acid methyl esters by addition of hydrogen chloride. The deuterium contents of saturated fatty acids and 3-chlorofatty acids were analyzed by gas chromatography-mass spectrometry. The oleic acid produced by the enzyme from B. ammoniagenes was oxidized to nonanoic acid and azelaic acid. The resulting nonanoic acid was also subjected to the action of acyl-CoA oxidase. The deuterium contents of nonanoic acid and trans-2-nonenoic acid were analyzed. The results suggested that fatty acid synthetase from yeast and rat liver incorporated hydrogen from water via a 2-Si attack and the enzyme from B. ammoniagenes incorporated hydrogen via a 2-Re attack during enoyl reduction. The partial racemization of the C-2 position was observed and the magnitude of this racemization was correlated with the deuterium content of synthesized fatty acids. This phenomenon may be attributed to the non-stereospecific hydrogen exchange of the C-2 position of the elongating acyl residue catalyzed by fatty acid synthetases.

Fatty acid synthetase from the Harderian gland of guinea pig: biosynthesis of methyl-branched fatty acids

Fatty acid synthetase was isolated from guinea pig Harderian gland. This enzyme complex exhibited a unique character as compared with the fatty acid synthetase from the liver of the same animal. The former enzyme produced many odd-numbered and methyl-branched fatty acids in the presence of methylmalonyl-CoA. These fatty acids are characteristic components of the lipid secreted from this gland. The chemical structure of this lipid has been identified as 1-O-alkyl-2,3-diacylglycerol by previous work from this laboratory (Yamazaki, T., Seyama, Y., Otsuka, H., Ogawa, H., & Yamakawa, T. (1981) J. Biochem. 89, 683-691). Apparent Km values (5 X 10(-6) M) for acetyl-CoA and propionyl-CoA were the same, but the Vmax for propionyl-CoA was much higher than that for acetyl-CoA. The pI value of the fatty acid synthetase from Harderian gland was 5.3, and the molecular weight of the enzyme was 9 X 10(5) daltons. The beta-ketoacyl reductase had pro-S stereospecificity and the enoly reductase had pro-R stereospecificity for NADPH. The results presented in this paper indicate that the fatty acid synthetase from guinea pig Harderian gland can produce a set of fatty acids needed for the synthesis of the lipid secreted from this gland, and that the fatty acid synthetase has a characteristic organ specificity.

Simplified determination of cholestanol in serum by gas-liquid chromatography: biochemical diagnosis of cerebrotendinous xanthomatosis

Cholestanol (5 alpha-cholestan-3 beta-ol) in human serum was determined by gas-liquid chromatography after removal by epoxidation of cholesterol which is present in amounts about 400 times those of cholestanol and disturbs the accurate determination of minor sterols in serum. Epicholestanol (5 alpha-cholestan-3 alpha-ol) was used as an internal standard. By this method the cholestanol content in sera of 7 patients with cerebrotendinous xanthomatosis was determined. The cholestanol levels in those sera were significantly higher than those of normal subjects and the present method proved to be useful in a biochemical diagnosis of cerebrotendinous xanthomatosis.

Steric course of reaction catalyzed by the enoyl acyl-carrier-protein reductase of Escherichia coli

The steric course of the reaction catalyzed by Escherichia coli enoyl acyl-carrier-protein reductase was studied. 1. trans-2-[2-2H1]Decenoic and trans-2-[3-2H1]decenoic acids were synthesized and converted to the corresponding decenoyl thiol esters with CoA or acyl carrier protein. These deuterium-labeled decenoyl thiol esters were incubated with purified enoyl acyl-carrier-protein reductase in the presence of NADPH or NADH. 2. The unlabeled trans-2-decenoyl thiol esters were incubated with enoyl acyl-carrier-protein reductase in the presence of (4S)-[4-2H1]NADH. The unlabeled decenoyl thiol esters were also incubated with the enzyme in 2H2O. The decanoic acids formed in the above incubations were extracted and subjected to the action of acyl-CoA oxidase, which had been previously shown to catalyze the anti elimination of the pro-2R and pro-3R hydrogens of acyl-CoA. The resulting products, 2-decenoyl-CoAs, were converted to methyl esters and their deuterium contents were analyzed by gas chromatography/mass spectrometry. The results suggested that the reduction catalyzed by E. coli enoyl acyl-carrier-protein reductase occurs by a syn addition of hydrogen via a 2-Re, 3-Si attack on the double bond.

Quantitative determination of individual non-sulfated bile acids and sulfated lithocholic acid in serum by mass fragmentography

Individual non-sulfated bile acids and sulfated lithocholic acid in serum were determined by mass fragmentography. A hexafluoroisopropyl ester-trifluoroacetyl derivative of bile acid was prepared by the method of Imai et al. (J. Chromatogr. 120, 181, 1976). Deuterium labeled deoxycholic acid was used as an internal standard monitoring at m/z 623. Lithocholic acid, deoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid, and cholic acid were determined by monitoring the intensities of m/z 622, m/z 620, m/z 620, m/z 620, ad m/z 618, respectively. A serum sample of 200 microliters including 500 ng of internal standard was hydrolyzed with strong alkali, then acidified to pH 1 with 2N HCl under cooling on ice, and extracted with diethyl ether immediately. Ether extracts were derivatized without further purification. Besides this assay of non-sulfated bile acids, total serum lithocholic acid including the sulfated form was determined as follows: extraction was performed after mixing the acidified (pH 1 with 2 N HCl) hydrolysate with ether and incubation at 40 degrees C for 2 h. Bile acid peaks in the mass fragmentogram were not affected by other materials in these serum extracts. The average values of individual non-sulfated bile acids in sera from healthy fasting subjects (n=15) were as follows: lithocholic acid, 0.049 micrograms/ml; deoxycholic acid, 0.462 micrograms/ml; chenodeoxycholic acid, 0.671 micrograms/ml; ursodeoxycholic acid, 0.070 icrograms/ml; and cholic acid, 0.217 micrograms/ml. Total lithocholic acid (non-sulfated and sulfated) in sera was 0.166 microgram/ml.

Identification of alkyldiacylglycerols containing saturated methyl branched chains in the Harderian gland of guinea pig

More than 90% of total lipids in the Harderian gland of guinea pig was identified as 1-alkyl-2,3-diacylglycerol. The alkyl and acyl moieties consisted of saturated aliphatic chains ranging from 14 to 21 carbon atoms and from 15 to 26 carbon atoms, respectively. About 60 mol% of them had methyl branches, which were located at the even-numbered carbon atoms. Mono- and di-methyl branched chains accounted for most of the branched chains. The aliphatic chains contained methyl branches especially in the alkyl chains at the 1-position and the acyl chains at the 2-position

Acyl phosphatidylglycerol of Escherichia coli

Acyl phosphatidylglycerol, isolated from Escherichia coli, has been identified as 3-sn-phosphatidyl-1'-(3'-acyl)-sn-glycerol. The fatty acids of the diacylglycerol moiety of acyl phosphatidylglycerol resemble those of phosphatidylglycerol in composition. However, the monoacylglycerol moiety of this lipid contains more unsaturated fatty acids than the diacylglycerol part of this lipid or other phospholipids in E. coli. Furthermore, the fatty acids present in the monoacylglycerol moiety, were found to contain major amounts of an unsaturated acid identified as 7-tetradecenoic acid by combined gas-liquid chromatography-mass spectrometry. This acid was present only in low concentrations in most phospholipids of E. coli.