Effects of gastrointestinal hormones on fasting gallbladder storage patterns in man

Björnsson, Ó. G.; Adrian, Thomas E.; Dawson, J.; McCloy, R F; Greenberg, Gordon R.; Bloom, Stephen R.; Chadwick, V. S.

doi:10.1111/j.1365-2362.1979.tb00887.x

Cited by 40 publications

(7 citation statements)

References 20 publications

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“…changes in pH (l, 9). Because indocyanine green is used s a marker to monitor hepato-biliary excretion into the duodenum (10)(11)(12), where pH and composition of the lumihal fluid is variable, we have in the present work studied the effects of storage and changes in pH on the spectro-photometric absorbance of indocyanine green in various biological fluids. The effects of high temperature on the rate of decay of indocyanine green in several organic solvents were also studied.…”

Section: Introductionmentioning

confidence: 99%

Physicochemical Studies on Indocyanine Green: Molar Lineic Absorbance, pH Tolerance, Activation Energy and Rate of Decay in Various Solvents

Björnsson¹,

Murphy²,

Chadwick³

et al. 1983

Clinical Chemistry and Laboratory Medicine

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Physicochemical studies were carried out on the tricarbocyanine dye indocyanine green in biological fluids and organic solvents. The molar lineic absorbance of the compound was highest in organic solvents (methanol, 1.2-propanediol, dimethylformamide) and bile, but lowest in water and duodenal fluid. Indocyanine green remained stable in methanol and bile (t 1/2 > l year) but was rapidly decomposed to a colourless derivative in duodenal fluid and distilled water (t 1/2 3.6 days and 1.4 days, respectively). It was thermostable (120 °C) in methanol and 1.2-propanediol but thermolabile in water and dimethylformamide where the activation energy for the decofnposition reaction was low. At ambient temperature (20 °C) indocyanine green was particularly labile at pH < 5 and pH > 11. The rate of decay of indocyanine green in various solvents indicated that the rate limiting Step in the decay process was either a first or zero order reaction.Physikochemische Untersuchungen an Indocyaningrün: Molare lineare Absorbanz, pH-Toleranz, Aktivierungsenergie und Zerfallsgeschwindigkeit in verschiedenen Lösungsmitteln Zusammenfassung: An dem Tricarbocyaninfarbstoff Indocyaningrün wurden physikochemische Untersuchungen in biologischen Flüssigkeiten und organischen Lösungsmitteln durchgeführt. Die molare lineare Absorbanz der Verbindung war am höchsten in organischen Lösungsmitteln (Methanol, 1,2-Propandiol, Dimethylformamid) und Galle, am. geringsten in Wasser und Duodenalsaft. Indocyaningrün war in Methanol und Galle stabil (tj/2 > l Jahr), wurde jedoch in Duodenalsaft und destilliertem Wasser sehr schnell zu einem farblosen Abkömmling zersetzt (ti/ 2 3,6 bzw. 1,4 Tage). Es war thermostabil (120 °C) in Methanol und 1,2-Propandiol, jedoch thefniolabil in Wasser und Dimethylformamid, in denen-die Aktivierungsenergie für die Zersetzungsreaktion niedrig war. Bei Umgebungstemperatur (20 °C) war der Farbstoff besonders labil bei pH<5 und pH> 11. Die Zerfallsgeschwindigkeit von Indocyaningrün in verschiedenen Lösungsmitteln zeigte, daß der Zerfallsprozeß eine Reaktionskinetik erster oder nullter Ordnung folgt.

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Section: Introductionmentioning

confidence: 99%

Physicochemical Studies on Indocyanine Green: Molar Lineic Absorbance, pH Tolerance, Activation Energy and Rate of Decay in Various Solvents

Björnsson¹,

Murphy²,

Chadwick³

et al. 1983

Clinical Chemistry and Laboratory Medicine

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“…Injections ofbovine PP (bPP) decrease food intake and body weight in the hyperglycemic ob/ob mouse (9), and injections of either the bovine or avian PP (aPP) cause New Zealand obese mice to revert to normal (10). Although these observations indicate that PP may act as a satiety factor, the peptide appears to have other physiological effects in addition, including increased gut motility and "gastrin-like" actions (11,12). Recent results indicate that PP is a member of a.larger family of homologous peptides found in the gut and in the brain (13).…”

mentioning

confidence: 98%

X-ray analysis (1. 4-Å resolution) of avian pancreatic polypeptide: Small globular protein hormone

Blundell

Pitts

Tickle

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

269

156

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The crystal structure of avian pancreatic polypeptide (aPP), a 36-residue polypeptide with some hormonal properties, has been determined by using single isomorphous replacement and anomalous scattering to 2.1-A resolution. The phases were extended to 1.4-A resolution by using a modified tangent formula. The molecule contains two regions ofsecondary structurean extended polyproline-like helix (residues 1-8) and an a-helix (residues 14-31) -that run roughly antiparallel. The packing together of nonpolar groups from these regions gives the molecule a hydrophobic core in spite of its small size. The aPP molecules form a symmetrical dimer in the crystal stabilized principally by interlocking of nonpolar groups from the a-helices. The aPP dimers are crosslinked by coordination ofZn"+; three aPP molecules contribute ligands to each zinc. The coordination geometry is a distorted trigonal bipyramid. The properties of the aPP molecule in solution are consistent with expectations based on the crystal structure. The aPP molecule has several general features in common with the pancreatic hormones insulin and glucagon. All three hormones have complex mechanisms for self-association. Like insulin, aPP seems to have a stable monomeric structure but its biological activity seems to depend on the more flexible COOH-terminal region analogous to the flexible NH2-terminal region of glucagon.Pancreatic polypeptide (PP) is a 36-amino acid peptide found in the endocrine pancreas (1, 2). There is close sequence homology among the mammalian peptides although mammalian and avian PPs differ at about 20 positions (Fig. 1). All sequences have an amidated COOH terminus, a feature known to occur in other polypeptide hormones such as gastrin, secretin, and oxytocin (3). There is now evidence that PP is synthesized as a larger precursor, in the same way as other pancreatic polypeptide hormones (4).The ultrastructural appearance ofthe PP-producing cells also strongly argues for an endocrine function for this peptide. PP is located in membrane-enclosed granules (5) like those of the alpha and beta pancreatic cells in which glucagon and insulin are synthesized. The PP cells are located on the periphery of the islets at the head of the pancreas, to the exclusion of glucagon cells which occur at the periphery of the islets of the tail end (6). In certain fishes such as the teleost Cottus scorpius, which has two principal islets, the pyloric region has mainly PP cells and the splenic contains no PP cells (7).PP is released into the circulation partly as a result of vagal cholinergic stimulation after feeding or in response to hypoglycemia. Although the half-life is of the order of 5 min the levels remain increased for several hours, indicating a continuous release (8). Injections ofbovine PP (bPP) decrease food intake and body weight in the hyperglycemic ob/ob mouse (9), and injections of either the bovine or avian PP (aPP) cause New Zealand obese mice to revert to normal (10). Although these observations indicate that PP may act as a satiety...

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“…ICG, trypsin and total bile salts were measured as described previously [4]. ICG in the duodenal fluid was measured spectrophotometrically using decolourized samples in strong HCI (pH < 0.1) as blanks [4, 61.…”

Section: Methodsmentioning

confidence: 99%

“…2,Part 11,p. the duodenum (6.4 mmol/l) just above the micellar point. Duodenal concentrations of bile salts in man have, however, been reported to reach far higher levels after a meal [2, 31. To study whether there was a relationship between the concentration of bile salts in the duodenum and the inhibitory effect on the biliary excretion, we have in the present work carried out dose-response studies with different concentrations of bile salts using various levels of exogenous biliary stimulation with caerulein, whilst monitoring the level of biliary excretion by the changes in duodenal recovery of intravenously administered indocyanine green (ICG) [4].…”

Section: Introductionmentioning

confidence: 99%

Effects of duodenal perfusion with sodium taurocholate on biliary and pancreatic secretion in man

Björnsson

Maton

Fletcher

et al. 1982

Eur J Clin Investigation

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The effects of intraluminal sodium taurocholate (STC) on biliary and pancreatic secretion were studied in man using a duodenal perfusion technique and indocyanine green (ICG) as an exogenous biliary marker. Duodenal perfusion with 15 or 30 mmol/l STC in healthy subjects markedly suppressed caerulein and secretin stimulated biliary indocyanine green (ICG) excretion in a dose responsive manner, i.e. to 40% (17-95%, +/- 2 SD, n = 5) (P less than 0.025) and 32% (26-38%, +/- 2 SD, n = 3) (P less than 0.003) of i.v. ICG infusion, respectively, with a maximum suppression to 26% and 10%, respectively. In cholecystectomized subjects (n = 5), significant changes in ICG excretion were not observed during STC (15 mmol/l) perfusion. There were no suppressive effects on pancreatic enzyme or bicarbonate secretion in any of the subjects. Our observations suggest that the bile salts STC in the duodenum in man activated a mechanism which selectively suppressed biliary excretion. This is probably due to relaxation of the gallbladder and an increase in gallbladder storage of bile.

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Effects of gastrointestinal hormones on fasting gallbladder storage patterns in man

Cited by 40 publications

References 20 publications

Physicochemical Studies on Indocyanine Green: Molar Lineic Absorbance, pH Tolerance, Activation Energy and Rate of Decay in Various Solvents

Physicochemical Studies on Indocyanine Green: Molar Lineic Absorbance, pH Tolerance, Activation Energy and Rate of Decay in Various Solvents

X-ray analysis (1. 4-Å resolution) of avian pancreatic polypeptide: Small globular protein hormone

Effects of duodenal perfusion with sodium taurocholate on biliary and pancreatic secretion in man

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