scholarly journals Changes of TLQP-21 in Response to Glucose Load

2019 ◽  
Author(s):  
Giulia Corda ◽  
Barbara Noli ◽  
Barbara Manconi ◽  
Carla Brancia ◽  
Manuela Pellegrini ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Insulin Secretion ◽  
Peak Concentration ◽  
High Performance ◽  
Endocrine Pancreas ◽  
Glucose Load ◽  
Terminal Portion ◽  
Endocrine Mechanism ◽  
The Common ◽  
Glucose Stimulated Insulin Secretion

AbstractThe TLQP-21 peptide peripherally potentiates glucose-stimulated insulin secretion. The aim of this study was to investigate a possible endocrine mechanism through which TLQP-21 increases the insulin secretion. Using an antibody specific for the common N-terminal portion of the TLQP peptides, we studied pancreas and plasma of mice subjected to intraperitoneal glucose load, by immunohistochemistry and immunosorbent assay (ELISA), alone or coupled to High Performance Liquid Chromatography (HLPC). Mice underwent a period of starvation hence have received a glucose load, or saline, and were sacrificed 30 or 120 minutes later. In normal endocrine pancreas, the TLQP-antiserum stained either peripheral or central cells. Interestingly, 30 min after a glucose load, TLQP immunostaining was disappeared in pancreas and, when analysed by ELISA, the TLQP-levels started to increase in plasma reaching peak concentration at 120 min. (controls vs. 30 and 120 min.: p<0.05 and p<0.001, respectively). The analysis of plasma and pancreas extracts using HLPC coupled to ELISA demonstrated the presence of the TLQP-21, with statistically significant increase of this peptide in plasma at 120 min (vs. controls p<0.05) in agreement to the changes seen by measuring the totality of the TLQP peptides. In pancreas sections we found the presence of the C3a-R1, involved in insulin secretion, and previously identified as a TLQP-21 receptor. Hence, after a glucose load, TLQP-21, may be released by the pancreas into the plasma, returning to the pancreas in order to modulate the insulin secretion through the C3a-R1.

scholarly journals Pharmacokinetics of sparfloxacin and interaction with cisapride and sucralfate.

1997 ◽  
Vol 41 (8) ◽  
pp. 1668-1672 ◽  
Author(s):  
J A Zix ◽  
H F Geerdes-Fenge ◽  
M Rau ◽  
J Vöckler ◽  
K Borner ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Peak Concentration ◽  
High Performance ◽  
Random Order ◽  
Pharmacokinetic Parameters ◽  
Qtc Interval ◽  
Urinary Recovery ◽  
Time Curve ◽  
Concentration Time

In an open, randomized, triple crossover study, the effects of cisapride and sucralfate on the pharmacokinetics of sparfloxacin were assessed. Fifteen healthy volunteers received 400 mg of sparfloxacin as a single oral dose on day 0. In a random order, concomitant doses of 10 mg of cisapride three times daily from day -2 to day 2 and 1 g of sucralfate four times daily from day -2 to day 0 were administered. Sparfloxacin concentrations were measured by bioassay and high-performance liquid chromatography. Pharmacokinetic parameters for sparfloxacin alone were as follows (mean +/- standard deviation): maximum concentration of drug in serum (C(max)), 1.27 +/- 0.39 microg/ml; time to C(max) (T(max)), 4.1 +/- 1.9 h; area under the concentration-time curve (AUC), 35.0 +/- 9.7 microg x h/ml; mean residence time, 28.5 +/- 5.7 h; half-life (t1/2), 20 +/- 4 h; urinary recovery (UR x f), 11.0% +/- 2.7%; and metabolite-sparfloxacin ratio in urine, 2.6. For the cisapride group there was a significant decrease in the sparfloxacin T(max) (1.9 +/- 2.1 h) and a significant increase in C(max) (1.74 +/- 0.73 microg/ml). The QTc interval for patients receiving sparfloxacin and cisapride was prolonged by 7.7% compared to the QTc interval during medication-free periods. Significant differences in the values for the group receiving sucralfate compared to the values for the group receiving sparfloxacin alone were found: C(max), 0.77 +/- 0.31 microg/ml; AUC, 18.6 +/- 5.8 microg x h/ml; t1/2, 26 +/- 10 h; and UR x f, 5.8 +/- 1.8%. Concomitant adminstration of cisapride accelerates the absorption and increases the peak concentration of sparfloxacin without having a significant effect on the extent of bioavailability. Coadministration of sucralfate leads to a 44% decrease in the bioavailability of sparfloxacin.

Aqueous oxidation of acetaminophen with monochloramine

2017 ◽  
Vol 18 (5) ◽  
pp. 1769-1774
Author(s):  
O. Abou Mehrez ◽  
F. Masri ◽  
M. Baroudi ◽  
F. Dossier-Berne
Keyword(s):  
Aqueous Solution ◽  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Order Rate Constant ◽  
Reversed Phase ◽  
Pain Reliever ◽  
Experimental Conditions ◽  
Ultraviolet Absorbance ◽  
The Common ◽  
Aqueous Oxidation

Abstract The reactivity of the common pain reliever acetaminophen (paracetamol or 4-acetamidophenol) with monochloramine in aqueous solution was investigated in this study. Initially, monochloramine demands of acetaminophen (AAP) and its chlorination byproduct, 1,4-benzoquinone, were determined in excess of oxidant at pH 8.5 and 25 °C. Monochloramine demands of AAP and 1,4-benzoquinone were respectively 1.2 (±0.2) and 4.4 (±0.3) mol/mol after 72 h of reaction. Chlorination reactions were also conducted under the same experimental conditions in order to compare the oxidant demands and the reactivity of free chlorine and monochloramine toward AAP and 1,4-benzoquinone. Chlorine demands of AAP and 1,4-benzoquinone were much more important than monochloramine demands and respectively accounted for 13.4 (±0.2) and 6.8 (±0.5) mol/mol. The reaction of AAP with monochloramine was monitored using reversed-phase high performance liquid chromatography with ultraviolet absorbance (HPLC-UV). AAP reacted with monochloramine to form simultaneously two first byproducts. The half-life of reaction was estimated to be 90 min. The apparent second-order rate constant (kapp2) for the reaction of AAP with monochloramine at pH 8.5 was 231 M−1·h−1.

The Comparative Amount of Acrylamide in Tahdig Prepared with the Most Common Edible Liquid and Solid Oils

2020 ◽  
Vol 16 (5) ◽  
pp. 776-780
Author(s):  
Behrouz Akbari-adergani ◽  
Asghar Ahmadi ◽  
Gholamreza Jahedkhanki ◽  
Ramin N. Nodehi ◽  
Parisa Sadighara
Keyword(s):  
Amino Acids ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Sunflower Oil ◽  
High Performance ◽  
Edible Oils ◽  
Solid Phase ◽  
Phase Extraction ◽  
The Common

Background: Due to the heating of amino acids with edible oils to high temperatures, different amounts of acrylamide are produced. Objective: The purpose of this study was to compare the level of acrylamide in the tahdig of bread and tahdig of potato prepared with the common liquid and solid edible oils, including sunflower, corn, canola, frying oil and solid oils. Methods: The tahdig of bread and potato was prepared under the same temperature and time with different oils. Acrylamide isolation was performed on a solid-phase extraction (SPE) cartridge and acrylamide was determined using High-performance liquid chromatography (HPLC). Results: The highest amount of acrylamide was obtained with sunflower oil in the tahdig of potato (194.091 mg/Kg) and the lowest amount of acrylamide was obtained with solid oil in the tahdig of bread (48.54 mg/Kg). For all the oils, the acrylamide content of the tahdig of potato was higher than bread. Conclusion: This study clearly demonstrated the involvement of the kind of oils in the formation of acrylamide in the tahdig of bread.

Opossum colonic mucosa contains uroguanylin and guanylin peptides

1996 ◽  
Vol 270 (4) ◽  
pp. G708-G716 ◽  
Author(s):  
F. K. Hamra ◽  
W. J. Krause ◽  
S. L. Eber ◽  
R. H. Freeman ◽  
C. E. Smith ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Isoelectric Point ◽  
High Performance ◽  
Colonic Mucosa ◽  
Intrinsic Pathway ◽  
Membrane Guanylate Cyclase ◽  
T84 Cells ◽  
Reverse Phase ◽  
Rp Hplc ◽  
Endocrine Mechanism

Uroguanylin and guanylin are structurally related peptides that activate an intestinal form of membrane guanylate cyclase (GC-C). Guanylin was isolated from the intestine, but uroguanylin was isolated from urine, thus a tissue source for uroguanylin was sought. In these experiments, uroguanylin and guanylin were separated and purified independently from colonic mucosa and urine of opossums. Colonic, urinary, and synthetic forms of uroguanylin had an isoelectric point of approximately 3.0, eluted from C18 reverse-phase high-performance liquid chromatography (RP-HPLC) columns at 8-9% acetonitrile, elicited greater guanosine 3', 5'-cyclic monophosphate (cGMP) responses in T84 cells at pH 5.5 than pH 8, and were not cleaved and inactivated by pretreatment with chymotrypsin. In contrast, colonic, urinary, and synthetic guanylin had an isoelectric point of approximately 6.0, eluted at 15-16% acetonitrile on C18 RP-HPLC columns, stimulated greater cGMP responses in T84 cells at pH 8 than pH 5.5, and were inactivated by chymotrypsin, which hydrolyzed the Phe-Ala or Try-Ala bonds within guanylin. Uroguanylin joins guanylin as an intestinal peptide that may participate in an intrinsic pathway for cGMP-mediated regulation of intestinal salt and water transport. Moreover, uroguanylin and guanylin in urine may be derived from the intestinal mucosa, thus implicating these peptides in an endocrine mechanism linking the intestine with the kidney.

scholarly journals Pharmacokinetics of Gatifloxacin and Interaction with an Antacid Containing Aluminum and Magnesium

1999 ◽  
Vol 43 (5) ◽  
pp. 1067-1071 ◽  
Author(s):  
Silke Lober ◽  
Susanne Ziege ◽  
Margot Rau ◽  
Gabriele Schreiber ◽  
Alain Mignot ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Standard Deviation ◽  
Crossover Study ◽  
Magnesium Hydroxide ◽  
Peak Concentration ◽  
High Performance ◽  
Area Under The Curve ◽  
Optimal Time ◽  
Comparison Of The Results

ABSTRACT The pharmacokinetics of gatifloxacin (400 mg orally) and the influence of the antacid aluminum magnesium hydroxide (20 ml of Maalox 70) on the bioavailability of gatifloxacin in 24 healthy volunteers were assessed. In an open, randomized, six-period crossover study, the volunteers received either gatifloxacin alone (treatments A and D); aluminum magnesium hydroxide concomitant with gatifloxacin (treatment C); or aluminum magnesium hydroxide 2 h before (treatment B), 2 h after (treatment E), or 4 h after gatifloxacin administration (treatment F). Gatifloxacin concentrations were measured by a validated bioassay and high-performance liquid chromatography. Pharmacokinetics of a single 400-mg dose of gatifloxacin alone were characterized as follows (mean ± standard deviation): peak concentration (C max), 3.8 ± 0.5 (treatment A) and 3.4 ± 0.9 (treatment D) μg/ml; time toC max, 1.4 ± 0.8 (treatment A) and 1.7 ± 0.7 (treatment D) h; area under the curve from time zero to infinity (AUC0–∞), 33.5 ± 5.9 (treatment A) and 31.4 ± 3.4 (treatment D) μg · h/ml; urine recovery, (83 ± 6)% (treatment A) and (84 ± 8)% (treatment D). Comparison of the results obtained by bioassay showed a good correlation. Aluminum magnesium hydroxide administration 2 h before (treatment B) or concomitant with (treatment C) gatifloxacin decreased the C max by 45% (2.1 ± 1.2 μg/ml) or even 68% (1.2 ± 0.4 μg/ml) highly significantly (P < 0.01). AUC0–∞ was significantly reduced from 33.5 ± 5.9 to 19.4 ± 6.9 μg · h/ml (by 42%) or even to 11.9 ± 3.3 μg · h/ml (by 64%) (P < 0.01). If aluminum magnesium hydroxide was given 2 h after gatifloxacin (treatment E), there was no significant reduction of concentration in serum but AUC0–∞ was significantly reduced from 31.4 ± 3.4 to 25.9 ± 5.3 μg · h/ml (18%) (P < 0.01). Aluminum magnesium hydroxide given 4 h after gatifloxacin (treatment F) showed no influence on the gatifloxacin pharmacokinetics. Therefore, the optimal time between gatifloxacin application and the intake of an aluminum-containing antacid should be 4 h.

scholarly journals Study on the hydrolysis process of food and feed samples using high pressure asher (HPA-S) to determine several amino acids by high performance liquid chromatography

2019 ◽  
Vol 2 (2) ◽  
pp. 44-50
Author(s):  
Chien Dinh Viet ◽  
Luyen Nguyen Tien ◽  
Hong Ngoc Nguyen Thi ◽  
Hieu Pham Cong ◽  
Thanh Do Tat ◽  
...  
Keyword(s):  
Amino Acids ◽  
High Pressure ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Hydrolysis Process ◽  
Food And Feed ◽  
The Common ◽  
Hydrolysis Of ◽  
Feed Samples

The study researchs on the hydrolysis process of food and feed samples using High Pressure&nbsp;Asher (HPA-S) to determine several amino acids by high-performance liquid&nbsp;chromatography (HPLC). HPA-S equipment is mainly used for samples treatment in analysis of&nbsp;metals by spectroscopy. However, the study also found that HPA-S can be used in hydrolysis of food&nbsp;and feed samples in order to analyze amino acids. The temperature of HPA-S equipment could reach&nbsp;300oC and maintain continuously at 130 bar pressure, completely digetsing the most complex&nbsp;samples matrix within an hour. The successful study of the application of HPA-S to hydrolyze&nbsp;samples in order to analyze amino acids makes the time of sample preparation significantly shorter&nbsp;but still gave the equivalent stability, even higher than the common samples hydrolyzation.

Does the B820 Subcomplex of the B880 Complex Retain Carotenoids?

1996 ◽  
Vol 51 (5-6) ◽  
pp. 309-318 ◽  
Author(s):  
Andrey Moskalenko ◽  
Olga Toropygina ◽  
Nina Kuznetsova
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Molecular Mass ◽  
Gel Electrophoresis ◽  
High Performance ◽  
Rhodospirillum Rubrum ◽  
Complex Structure ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
The Common

Abstract A study is reported on the modification of the B880-RC assembly of Chromatium minutissimum during octyl-β-D -glucopyranoside/dodecyl-β-D -maltoside/Deriphat polyacrylamide gel electrophoresis followed by electroelution with dodecyl-β-D-maltoside and high performance liquid chromatography with octyl-β-D-glucopyranoside according to the method developed by Kerfeld et al. (Biochim. Biophys. Acta 1185, 193-202 [1994a]) for isolation of the B820 subcomplexes of Chromatium purpuratum. The B880-RC assembly of Chromatium minutissimum isolated by electrophoresis was contaminated by the B 800-850 complex. It was further separated into four components, three of which were in agreement with the cited work: (i) colorless contaminations, (ii) the B880-RC assembly, (iii) the B 800-850 complex. In contrast with Kerfeld et al. (1994a), the fourth band was a band of free pigments (Bchl or Bchl-t-carotenoids) which had the same molecular mass as the B820 subcomplex of Chromatium purpuratum. For comparison, the B880-RC enriched fraction of Rhodospirillum rubrum modified by lyophilization in the presence of octyl-β-D-glucopyranoside with or w ithout carotenoids was separated by high performance liquid chromatography with octyl-β-D-glucopyranoside. The apparent molecular mass of the B820 subcomplex was 30 kD a for the sample without carotenoids and 245 kD a for that with carotenoids. The common principles of organization of the B880 complex, the interaction of the B 800- 850 complex with the B880-RC assembly, the participation of carotenoids in the stabilization of the B880 complex structure and the ability of different isolation steps to modify the structure of the B880 complex are discussed. It was concluded that there are other explanations for the presence of carotenoids in the B820 subcomplex. Hence, the question of whether the B820 subcomplex retains carotenoids remains open.

scholarly journals Long-term increase of insulin secretion in mice subjected to pregnancy and lactation

2020 ◽  
Vol 9 (4) ◽  
pp. 299-308 ◽  
Author(s):  
Julia Modesto Vicente ◽  
Junia Carolina Santos-Silva ◽  
Caio Jordão Teixeira ◽  
Dailson Nogueira de Souza ◽  
Jean Franciesco Vettorazzi ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Endocrine Pancreas ◽  
Morphological Changes ◽  
Maternal Risk ◽  
Intracellular Ca ◽  
Pregnancy And Lactation ◽  
Molecular Aspects ◽  
Glucose Stimulated Insulin Secretion

Purpose Observational studies show that longer breastfeeding periods reduce maternal risk of type 2 diabetes mellitus. However, it is currently unknown if the long-term benefits of breastfeeding for maternal glucose homeostasis are linked to changes in the endocrine pancreas. Methods We presently evaluated functional, morphological and molecular aspects of the endocrine pancreas of mice subjected to two sequential cycles of pregnancy and lactation (L21). Age-matched mice not allowed to breastfeed (L0) and virgin mice were used as controls. Results L21 mice exhibited increased tolerance and increased glucose-stimulated insulin secretion (GSIS) by isolated islets. Pancreatic islets of L21 mice did not present evident morphological changes to justify the increased GSIS. On the other hand, islets of L21 mice exhibited a reduction in Cavb3 and Kir6.2 expression with concordant increased intracellular Ca2+ levels after challenge with glucose. Conclusion Altogether, the present findings show the breastfeeding exerts long-term benefits for maternal endocrine pancreas by increasing intracellular Ca2+ levels and GSIS.

High Performance Liquid Chromatography of Anthocyanidins as a New Approach to Study Flower Pigment Genetics

1980 ◽  
Vol 35 (1-2) ◽  
pp. 16-19 ◽  
Author(s):  
Naaman Akavia ◽  
Dieter Strack
Keyword(s):  
High Performance Liquid Chromatography ◽  
Acetic Acid ◽  
Phosphoric Acid ◽  
High Performance ◽  
Rapid Screening ◽  
Linear Gradient ◽  
New Approach ◽  
Flower Pigment ◽  
The Common ◽  
Accurate Quantification

Abstract The described method allows rapid screening and accurate quantification of anthocyanidins with the aid of HPLC. Using a linear gradient in 40 m in from 20 to 40% of solvent B (1.5% phosphoric acid -20% acetic acid - 25% acetonitrile) in solvent A (1.5% phosphoric acid) + B on LiChrosorb RP-8 the common six anthocyanidins delphinidin, cyanidin, petunidin, pelargonidin, peonidin, and malvidin were resolved within 40 min. It is demonstrated that acetonitrile is superior to other solvents in resolving methoxylated phenolic compounds. The application of the described method is shown with Gladiolus petals in studies of flower pigment genetics.

Sign in / Sign up

Export Citation Format

Share Document