Regulation of pancreatic and gallbladder functions by intraluminal fatty acids and bile acids in man

The effects of intraduodenal glycerol, fatty acid (FA) chain length and FA loads, and bile acid (BA) concentrations on pancreatic and gallbladder function were investigated in 31 healthy volunteers by a perfusion method. FA absorption rates in the duodenum and proximal jejunum were measured simultaneously. Pancreatic and gallbladder responses were augmented by increasing FA chain length and FA loads until the "maximal" secretory capacity of the pancreas and gallbladder emptying was attained. Glycerol had no effect. Raising BA concentrations above the critical micellar concentration accelerated FA absorption rates but decreased the magnitude of pancreatic and gallbladder responses to FA. Higher BA concentrations exerted an opposite effect, slowing FA absorption and increasing pancreatic and gallbladder responses. Indeed, a significant, inverse correlation was found between FA absorption and pancreatic and gallbladder responses to FA, suggesting a relationship between the length of intestine exposed to FA and the amount of cholecystokinin (and/or other neurohormonal factors) released, which stimulates pancreatic secretion and gallbladder contraction.     

Free fatty acids enhance hypochlorous acid production by activated neutrophils

Activated polymorphonuclear neutrophils (PMNs) may contribute to the genesis of chronic obstructive lung disease in long-term cigarette smokers. However, it is not presently known which elements in smoke are important in triggering this progressive pulmonary damage or in affecting the activities of inflammatory cells such as PMNS. We earlier found substances in organic concentrates of cigarette smoke that bound ferrous iron and transferred the metal into organic phases. These substances were later identified as saturated free fatty acids, predominantly palmitic and stearic acids (16:0 and 18:0). We now report investigations of the effects of fatty acids on the oxidative metabolism of PMNs. In accord with most earlier reports, we find that saturated fatty acids have little direct effect on PMN oxidative metabolism. However, micromolar amounts of free fatty acids will more than double production of hypochlorous acid (HOCl) by PMNs stimulated with small amounts of phorbol myristate acetate. Similar fatty acid-mediated increases in HOCl production also occur when PMNs are stimulated with 1,2-dioctanoyl-sn-glycerol and 1-oleoyl-2-acetyl-sn-glycerol (also thought to be agonists of protein kinase C) but not when cells are stimulated with the calcium ionophore A23187, the formylated tripeptide f-met-leu-phe, or opsonized zymosan. Fatty acid-mediated enhancement of PMN HOCl production evidently arises from increased release of myeloperoxidase from stimulated PMNs. Furthermore, in the presence of free fatty acids, stimulated PMNs are much more cytotoxic toward cultured mink lung epithelial cells, a toxicity that is blocked by scavengers of HOCl. These results suggest that the relatively large amounts of free fatty acids present in tobacco smoke may act to amplify PMN-mediated oxidative damage to the lungs of smokers.     

The gas chromatographic analysis of the higher fatty acids of bile lipids

The method of performing of abdominoanal rectal resection with anal hemiresection for tumor, localized in inferoampullar rectal portion and spreading on anus.     

Free fatty acids and cholesterol as possible participants in lipid oxidation radical reactions in animal tissues

Alterations in concentration of free fatty acids, free cholesterol, native antioxidants as well as in the antioxidative activity were studied in lipids of mice liver tissue and small intestinal mucosa. The intensity of free radical reactions in lipids of animal tissues was affected directly by administration of synthetic inhibitors of the reactions. The inverse correlation was observed between the alteration in concentrations of native antioxidants and free fatty acids as well as between the antioxidative activity of lipids and amount of free cholesterol in them. Free fatty acids appears to be the constant participants in the system of free radical oxidation of lipids, while cholesterol can center the system under distinct level of these reactions intensity.     

Formation and inhibition of lysolecithin in human gallbladder bile

Homogenized human gallbladder epithelium was incubated at 37 degrees C with 14C-lecithin in diluted gallbladder bile. During the incubation, lecithin was transformed to lysolecithin. The reaction rate was higher at pH 4.5 than at pH 7.0. No degradation of lecithin occurred if the reaction mixture did not contain the homogenate. Lysolecithin was mixed with red blood cells in (a) diluted human gallbladder bile and (b) 0.15 M saline. The surface activity in the different systems was then assessed from the amount of hemoglobin recovered in the red cell pellet after centrifugation. In human bile, 500 mug lysolecithin/ml did not affect the amount of hemoglobin recovered whereas in saline, concentrations exceeding 25-30 mug/ml affected the red blood cells such that no hemoglobin was pelleted by the centrifugation. Lysolecithin was further studied for effect upon lecithin-3H-cholesterol-dicetylphosphate liposomes containing 14C-glucose. The surface activity of lysolecithin was assessed from the distribution of 3H- and 14C-activity after centrifugation. Although 500 mug lysolecithin/ml increased the non-sedimented 14C-activity, 5000 mug lysolecithin/ml was necessary to decrease significantly the amount of sedimented 3H-activity. The results are interpreted such that phospholipase A activity from the gallbladder epithelium, if released into the gallbladder bile, may generate lysolecithin from lecithin. However, the surface activity and, thus, the inflammatory mediating activity of lysolecithin is inhibited by components in the gallbladder bile, possibly lecithin.     

Gallstone formation and gallbladder bile composition after colectomy in dogs

A high prevalence of gallstones has been described in patients following colectomy. The aim of this study was to examine whether lithogenicity is attributed to colectomy. In the present study, changes in gallbladder bile composition and the mechanism of gallstone formation after colectomy were examined in dogs. Ten mongrel dogs underwent restorative proctocolectomy. Seven dogs which received sham operations served as controls. Over a 12-week postoperative period, samples of gallbladder bile, formed gallstones and serum were collected and analyzed. In 7 of the 10 (70%) colectomized dogs, gallstones were found in the gallbladder, while the control dogs had no stones. Macroscopically the gallstones were similar to black pigment stones observed in humans. Chemical analysis and Fourier transform-infrared spectroscopy examination revealed that the stones were composed mainly of sodium bilirubinate and proteins, with minor amounts of calcium salts and cholesterol. Significant increases in biliary pH and concentrations of ionized calcium and unconjugated bilirubin were observed in the gallbladder bile of the colectomy group compared with that of the control group. The total bile acid and total bilirubin concentrations were significantly decreased in the colectomy group. Cholesterol crystal nucleation did not occur. The inhibitory effect of gallbladder bile on calcium carbonate precipitation in an in vitro assay system was preserved even after colectomy. In conclusion, proctocolectomy increases the concentration of unconjugated bilirubin in gallbladder bile and induces pigment gallstones which are composed mainly of sodium bilirubinate and proteins since calcium ions and cholesterol are stabilized in dogs.     

Postprandial serum bile acids in healthy man. Evidence for differences in absorptive pattern between individual bile acids

The serum concentrations of cholic acid (C), chenodeoxycholic acid (CD), and deoxycholic acid (D) before and after a standardised meal were determined in five healthy female subjects using a highly specific and accurate gas chromatographic-mass spectrometric technique. The C level rose significantly 60 minutes after the meal, reached a peak after 90 minutes, and had returned to the original level after 150 minutes. In contrast, the serum concentrations of CD and D displayed a significant rise by 30 minutes, reached a peak after 90 minutes, but had not returned to fasting levels after 150 minutes. The serum bile acid responses after a meal suggest that there is considerable absorption of dihydroxy bile acids in the proximal small intestine in man.     

Serum bile acids in cholestasis of pregnancy

Using routine liver function tests, cholestasis of pregnancy was diagnosed in 86 pregnant women with pruritus. Serum aminotransferase levels were elevated in all cases, ASAT in 99%, and ALAT in 100%. In these patients serum concentrations of cholic, chenodeoxycholic, and deoxycholic acid were determined using a gas chromatographic method and were compared with those in a group of 40 uncomplicated pregnancies. Of these bile acids, cholic acid levels were most frequently elevated, ie, in 92% of the patients. The frequency of elevation of serum levels of alkaline phosphatase, and total and conjugated bilirubin was lower. Thus, it appears that in addition to serum aminotransferase levels the serum cholic acid concentration is a sensitive indicator of cholestasis of pregnancy. The cholestasis series was divided into 3 subgroups of increasing severity of cholestasis as assessed by maternal serum cholic acid levels, and the occurrence of signs of fetal distress was compared between these subgroups. The only intrauterine fetal loss in the series belonged to the severe cholestasis group. The incidence of meconium-stained amniotic fluid also increased significantly in this group, and 21 of the 24 cases with other signs of fetal distress were in the groups of moderate and severe cholestasis.     

Long-chain polyunsaturated fatty acids

Long-chain polyunsaturated fatty acids (LC-PUFA) are essential for normal development. Fetal accretion of LC-PUFA occurs during the last trimester of gestation; therefore, premature infants are born with minimal LC-PUFA reserves. Recent studies indicate that the newborn can synthesize LC-PUFA from essential fatty acid precursors; however, the extent of de novo synthesis remains to be established. Postnatally, human milk provides LC-PUFA to the newborn. Maternal LC-PUFA reserves depend upon diet and can be improved by supplementation of docosahexaenoic acid and arachidonic acid during pregnancy and lactation. This in turn affects fetal LC-PUFA accretion and postnatal provision through mother's milk. Supplementation of formula-fed preterm or full-term infants with docosahexaenoic acid and arachidonic acid leads to plasma and red blood cell LC-PUFA levels similar to those of breast-fed infants. The higher blood and presumably tissue levels of LC-PUFA following supplementation lead, however, to only temporary functional benefits.     

Polyunsaturated fatty acids in infant nutrition

The availability of long-chain polyunsaturated fatty acids (LCP), such as arachidonic (C20:4n-6) and docosahexaenoic (C22:6n-3) acids, is important for early human growth and development. The capacity for endogenous synthesis of LCP from the precursor fatty acids linoleic (C18:2n-6) and alpha-linolenic (C18:3n-3) acid is limited in preterm and probably also in term infants. In utero, LCPs seem to be transferred preferentially from the mother to the foetus by the placenta. After birth, breast-fed infants receive preformed dietary LCP with human milk. In contrast, most current infant formulae are devoid of LCP. Premature infants fed such formulae develop rapid LCP depletion of plasma and tissue lipids, which is associated with reduced visual acuity during the first postnatal months. Therefore, LCP enrichment of formulae for premature infants is desirable. Recent observations indicate that term infants fed conventional formulae also exhibit lower plasma LCP values and may show functional disadvantages, but these data require further confirmation prior to drawing definite conclusions.     

Acute effects of dietary fatty acids on the fatty acids of human milk

1. Effects on 5-HT function of sibutramine and its active metabolites, BTS 54 354 and BTS 54 505, were compared with fluoxetine, (+)-fenfluramine and (+)-amphetamine. 2. In vitro sibutramine weakly inhibited [3H]-5-HT uptake into brain synaptosomes. BTS 54 354, BTS 54 505 and fluoxetine were powerful [3H]-5-HT uptake inhibitors, whereas (+)-fenfluramine and (+)-amphetamine were very much weaker. Conversely, whilst sibutramine, its metabolites and fluoxetine did not release [3H]-5-HT from brain slices at < or = 10(-5)M, (+)-fenfluramine and (+)-amphetamine concentration-dependently increased [3H]-5-HT release. 3. Sibutramine and fluoxetine had no effect on 5-hydroxytryptophan (5-HTP) accumulation in either frontal cortex or hypothalamus at doses < 10 mg kg(-1). In contrast, (+)-amphetamine ( > or = 3 mg kg(-1)) reduced 5-HTP in hypothalamus, whilst (+)-fenfluramine (> or =1 mg kg(-1)) decreased 5-HTP in both regions. 4. Sibutramine (10 mg kg(-1) i.p.) and fluoxetine (10 mg kg(-1) i.p.) produced slow, prolonged increases of extracellular 5-HT in the anterior hypothalamus. In contrast, (+)-fenfluramine (3 mg kg(-1) i.p.) and (+)-amphetamine (4 mg kg(-1) i.p.) induced rapid, short-lasting increases in extracellular 5-HT. 5. Only (+)-fenfluramine (10 mg kg(-1)) altered 5-HT2A receptors in rat frontal cortex when given for 14 days, producing a 61% reduction in receptor number and a 18% decrease in radioligand affinity. 6. These results show that sibutramine powerfully enhances central 5-HT function via its secondary and primary amine metabolites; this effect, like that of fluoxetine, is almost certainly mediated through 5-HT uptake inhibition. By contrast, (+)-fenfluramine enhances 5-HT function predominantly by increasing 5-HT release. (+)-Amphetamine, though weaker than (+)-fenfluramine, also enhances 5-HT function by release.     

Developmental pattern of 3-oxo-delta 4 bile acids in neonatal bile acid metabolism

AIMS: To investigate whether a fetal pathway of bile acid synthesis persists in neonates and infants. METHODS: 3-oxo-delta 4 bile acids were determined qualitatively and quantitatively in the urine, meconium, and faeces of healthy neonates and infants, using gas chromatography-mass spectrometry. RESULTS: The mean percentage of 3-oxo-delta 4 bile acids in total bile acids in urine at birth was significantly higher than that at 3 or 7 days, and at 1 or 3 months of age. The concentration of this component in meconium was significantly higher than that in faeces at 7 days and at 1 or 3 months of age. CONCLUSIONS: The presence of large amounts of urinary 3-oxo-delta 4 bile acids may indicate immaturity in the activity of hepatic 3-oxo-delta 4-steroid 5 beta-reductase in the first week of postnatal life. Large amounts of this component in meconium may be due to the ingestion of amniotic fluid by the fetus during pregnancy.     

Sulfate bile acids in germ-free and conventional mice

Sulfated and non-sulfated bile acids were determined in the intestines and in the feces of 7-month-old germ-free and conventional male mice. 1. The bile acid pools in the gall bladder and small intestine were 21.13 mg/100g body weight in germ-free and 11.50 mg in conventional mice. The bile acid pools in the cecum and large intestine of germ-free mice were 3.03 mg/100 g body weight as compared to 1.24 mg in conventional mice. Fecal bile acid excretion was 2.93 mg and 4.12 mg/100 g body weight in 24 h in germ-free and conventional mice respectively. 2. The major bile acids from germ-free mice were cholic acid, alpha-muricholic acid and beta-muricholic acid. Small amounts of chenodeoxycholic and allocholic acid were also present. In addition to these primary bile acids the following secondary bile acids were identified in conventional mice: lithocholic, deoxycholic and omega-muricholic acid. 3. In both germ-free and conventional animals significant amounts of chenodeoxycholic and cholic acid were present as the 7-monosulfate esters. The sulfate esters of these bile acids did not exceed 2% of the total bile acids in the small intestine, but accounted for approximately 50% of the bile acids in the cecum and the large intestine. In contrast, the muricholic acids were nearly exclusively found in the non-sulfate fraction. 4. Alkaline hydrolysis without prior solvolysis of the sulfate esters resulted in loss of bile acids and production of artifacts. Hence, the bile acids of the mouse cannot be analysed by methods involving alkaline deconjugation unless a solvolysis step is included in the procedure.     

Direct spectrophotometry of total bile acids in serum

In this simple and direct method for determining total bile acids in serum, the serum was mixed with sodium pyruvate, a lactate dehydrogenase blocker, and bile acids were then measured spectrophotometrically after the following enzyme reaction. Bile acids are converted to 3-oxo bile acids with 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) with concomitant reduction of NAD+ to NADH. The hydrogen in the NADH generated is transferred by diaphorase (EC 1.6.4.3) to nitrotetrazolium blue to yield diformazan 540 nm). Analytical recovery of the various bile acids in serum averaged 96.2%. The CV for the day-to-day variation was 4.3%. Normal values are less than 7 mumol/L. Total serum bile acids were estimated by this method in 118 fasting patients with various liver diseases. This determination is clearly shown to be useful as a liver-function test.     

Infrared spectra of bile, ionized, and conjugated bile acids

The ionization and conjugation effect on infrared spectra of bile acids has been studied. The interpretation of spectra of native bile absorption in the infrared range was conducted with allowance for different types of functional groups oscillations.     

The role of bile and bile acids in bacterial translocation in obstructive jaundice in rats

Eight independent chl (chromosome loss) mutants were isolated using yeast haploid strain disomic for chromosome III. In these mutants, chromosome III is lost during mitosis 50-fold more frequently than in the wild-type strains. chl mutants are also incapable of stable maintenance of circular and linear artificial chromosomes. Seven of the eight mutations are recessive, and one is semidominant. Complementation tests placed these mutants into six complementation groups (chl11 through chl16). Based on tetrad analysis, chl12, chl14 and chl15 correspond to mutations in single nuclear genes. Tetrad analysis of the other mutants was not possible due to poor spore viability. Complementation analysis was also carried out between collection of chl mutants and ctf mutants (chromosome transmission fidelity) (Spencer et al., 1990). The chl3, chl4, chl8, chl12 and chl15 mutants were unable to complement ctf3, ctf17, ctf12, ctf18 and ctf4, respectively. Three CHL genes were mapped by tetrad analysis. The CHL3 gene is placed on the right arm of chromosome XII, between the ILV5 (33.3 cM) and URA4 (21.8 cM) loci. The CHL10 gene is located on the left arm of chromosome VI, 12.5 cM from the centromere. The CHL15 gene is tightly linked to the KAR3 marker of the right arm of chromosome XVI (8.8 cM). The mapping data indicate that these three genes differ from other genes known to affect chromosome stability in mitosis. Therefore, the total number of the CHL genes identified (including those described by us earlier) is 13 (CHL1-CHL10, CHL12, CHL14 and CHL15).