The Hyperglycemic Effect of 1-Deoxy-D-manno-heptulose. Inhibition of Hexokinase, Glucokinase, and Insulin Release in Vitro

1974 ◽  
Vol 52 (11) ◽  
pp. 1078-1081
Author(s):  
B. Leshem ◽  
Y. Sharoni ◽  
E. Dimant
Keyword(s):  
Insulin Release ◽  
Rat Liver ◽  
Inhibitory Effect ◽  
Hydroxyl Group ◽  
Primary Hydroxyl ◽  
Rabbit Pancreas ◽  
Release In Vitro ◽  
Yeast Hexokinase ◽  
Hyperglycemic Effect

Injection of 1-deoxy-D-manno-heptulose (1-DMH, 400 mg, subcutaneously) into rats is associated with a hyperglycemia which reaches a peak after 2 h and is about half that caused by the same dose of D-manno-heptulose (MH). Insulin release from pieces of rabbit pancreas suspended in 15 mM glucose and 20 mM 1-DMH was about 20% of the release in the absence of 1-DMH. Under the same conditions MH caused a complete block of insulin release. Yeast hexokinase was inhibited to the extent of 58% and 68% by 1-DMH and MH (14.3 mM), respectively. 1-DMH is also inferior to MH as an inhibitor of crude rat liver hexokinase and glucokinase. The primary hydroxyl group on carbon-1 of MH is not required for the heptulose to exert its inhibitory effect on hexokinase.

Insulin secretion in glucosamine-induced hyperglycemia in rats

1965 ◽  
Vol 209 (4) ◽  
pp. 797-802 ◽  
Author(s):  
Julio M. Martin ◽  
Gunta Bambers
Keyword(s):  
Insulin Secretion ◽  
Blood Glucose ◽  
Insulin Release ◽  
Glucose Concentration ◽  
Insulin Injection ◽  
Inhibitory Effect ◽  
Base Line ◽  
Pancreatic Insulin ◽  
Hyperglycemic Effect

The hyperglycemia response produced by the injection of glucosamine in rats has been studied by comparing the effects of equal doses of glucosamine and glucose on blood glucose, circulating insulin, and pancreatic insulin content. The effect of glucosamine and glucose on insulin release from the islets has been studied in vitro by incubating slices of pancreas from normal rats and from rats injected with glucosamine. After glucosamine injection, the blood glucose rose and the circulating insulin decreased. In the glucose-injected group the hyperglycemia was lower and the circulating insulin higher. Insulin output from incubated pancreatic slices of normal rats rose when the glucose concentration in the medium was increased or when tolbutamide was added. A decrease below the base line occurred on the addition of glucosamine or when pancreas slices from glucosamine-injected rats were incubated. Insulin injection decreased the hyperglycemic effect of glucosamine whereas tolbutamide was ineffective. These results suggest that glucosamine exerts an inhibitory effect on insulin release from the pancreas.

Augmentation of glucose induced insulin secretion by pertussis vaccine, phentolamine and benextramine: involvement of mechanisms additional to prevention of the inhibitory actions of catecholamines in rats

1988 ◽  
Vol 118 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Maureen Smith ◽  
Brian L. Furman
Keyword(s):  
Insulin Secretion ◽  
Insulin Release ◽  
Pertussis Vaccine ◽  
Ex Vivo ◽  
Blocking Agent ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Release In Vitro ◽  
The Relationship

Abstract. Pertussis vaccine, pertussis toxin, and the α-adrenoceptor blocking drug phentolamine augment glucose-induced insulin secretion. The present study was carried out to determine the relationship between this action and the ability of these agents to prevent the inhibitory actions of adrenaline. Pertussis vaccine augmented glucose-induced insulin secretion in rat islets ex vivo and prevented the inhibitory actions of adrenaline and clonidine. Incubation of islets with phentolamine or the irreversible α-adrenoceptor blocking agent benextramine also augmented glucose-induced insulin secretion. However, the α-adrenoceptor blocking drugs idazoxan, yohimbine or phenoxybenzamine, in concentrations that prevented the inhibitory effects of adrenaline and/or clonidine, did not modify glucose-induced insulin release in vitro. Benextramine (1 × 10−5 mol/l) blocked the inhibitory effect of clonidine, whilst having no significant effect on the response to adrenaline. It is concluded that stimulation of insulin secretion by certain α-adrenoceptor blocking drugs can be dissociated from their α-adrenoceptor properties. The ability of pertussis vaccine, phentolamine or benextramine to augment glucose-induced insulin release in vitro is unlikely to be due to the prevention of the inhibitory action of endogenous catecholamines.

Monolayer Culture of Human Fetal and Adult Pancreas. Static and Dynamic Studies of Insulin Release In Vitro

1980 ◽  
Vol 12 (08) ◽  
pp. 354-360 ◽  
Author(s):  
S. Kawazu ◽  
Y. Kanazawa ◽  
M. Hayashi ◽  
M. Ikeuchi ◽  
T. Nakai ◽  
...  
Keyword(s):  
Insulin Release ◽  
Monolayer Culture ◽  
Dynamic Studies ◽  
Release In Vitro

scholarly journals Validation of an HPLC Method for the Simultaneous Quantification of Metabolic Reaction Products Catalysed by CYP2C11 Enzymes in Rat Liver Microsomes: In Vitro Inhibitory Effect of Salicylic Acid on CYP2C11 Enzyme

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4294 ◽  
Author(s):  
Salhab ◽  
Naughton ◽  
Barker
Keyword(s):  
High Performance Liquid Chromatography ◽  
Enzyme Activity ◽  
Salicylic Acid ◽  
Liquid Chromatography ◽  
Rat Liver ◽  
High Performance ◽  
Inhibitory Effect ◽  
Metabolic Reaction ◽  
Rat Liver Microsomes

The inhibitory effect of new chemical entities on rat liver P450 marker activities was investigated in a functional approach towards drug development. Treatment of colorectal cancer (CRC) and chemoprevention using salicylic acid has gained a lot of attention, mainly in the prevention of the onset of colon cancer. Thus, an in vitro inhibitory effect of salicylic acid on rat CYP2C11 activity was examined by using high performance liquid chromatography (HPLC). High performance liquid chromatography analysis of a CYP2C11 assay was developed on a reversed phase C18 column (SUPELCO 25 cm × 4.6 mm × 5 µm) at 243 nm using 32% phosphate buffer (pH 3.36) and 68% methanol as a mobile phase. The CYP2C11 assay showed good linearity for all components (R2 > 0.999). Substrates and metabolites were found to be stable for up to 72 hours. Additionally, the method demonstrated good reproducibility, intra- and inter-day precision (<15%), acceptable recovery and accuracy (80%–120%), and low detection (1.3501 µM and 3.2757 µM) and quantitation limit values (4.914 µM and 9.927 µM) for 16α-hydroxytestosterone and testosterone, respectively. Salicylic acid acts reversibly as a noncompetitive (weak) inhibitor with Ki = 84.582 ± 2.67 µM (concentration of inhibitor to cause 50% inhibition of original enzyme activity (IC50) = 82.70 ± 2.67 µM) for CYP2C11 enzyme activity. This indicates a low potential to cause toxicity and drug–drug interactions.

Different effects of antipsychotic drugs on insulin release in vitro

2001 ◽  
Vol 11 (5) ◽  
pp. 327-332 ◽  
Author(s):  
Kristina Melkersson ◽  
Akhtar Khan ◽  
Agneta Hilding ◽  
Anna-Lena Hulting
Keyword(s):  
Insulin Release ◽  
Antipsychotic Drugs ◽  
Release In Vitro

Inhibitory Effect of Resveratrol on the Pharmacokinetics of Ticagrelor in Vivo and Vitro

2021 ◽  
Author(s):  
Peng Wang ◽  
Xiao-Xia Hu ◽  
Ying-hui Li ◽  
Nan-Yong Gao ◽  
Guo-quan Chen ◽  
...  
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Control Group ◽  
Rat Liver Microsomes ◽  
Sprague Dawley ◽  
Group B

This study was to evaluate the effect of resveratrol on the pharmacokinetics of ticagrelor in rats and the metabolism of ticagrelor in human CYP3A4 and liver microsomes. Eighteen Sprague-Dawley rats were randomly divided into three groups: group A (control group), group B (50mg/kg resveratrol), and group C (150mg/kg resveratrol ). After 30 minutes administration of resveratrol, a single dose of ticagrelor (18mg/kg) was administered orally. The vitro experiment was performed to examine the influence of resveratrol on ticagrelor metabolism in CYP3A4*1, human, and rat liver microsomes. Serial biological samples were assayed by validated UHPLC-MS/MS methods. In vivo study, the AUC and Cmax of ticagrelor in group B and C appeared to be significantly higher than the control group, while Vz/F and CLz/F of ticagrelor in group B and C were significantly decreased. In vitro study, resveratrol exhibited an inhibitory effect on CYP3A4*1, human and rat liver microsomes. The IC50 values of resveratrol were 56.75μM，69.07μM and 14.22μM, respectively. Our results indicated that resveratrol had a inhibitory effect on the metabolism of ticagrelor in vitro and vivo. It should be paid more attention to the clinical combination of resveratrol with ticagrelor and ticagrelor plasma concentration should be monitored to avoid the occurrence of adverse reaction.

THE STIMULATION OF INSULIN RELEASE BY ESSENTIAL AMINO ACIDS FROM RABBIT PANCREAS IN VITRO

1970 ◽  
Vol 47 (3) ◽  
pp. 347-356 ◽  
Author(s):  
R. D. G. MILNER
Keyword(s):  
Amino Acids ◽  
Insulin Release ◽  
Incubation Medium ◽  
Statistical Significance ◽  
Adenosine Monophosphate ◽  
Essential Amino Acids ◽  
Isoleucine Leucine ◽  
Rabbit Pancreas

SUMMARY Pieces of rabbit pancreas were incubated in vitro in an incubation medium containing no glucose or 1·5 mg. glucose/ml. In each of these conditions the effect on insulin release of each of the essential amino acids at 5 mm concentration was studied. Leucine was the only essential amino acid that stimulated insulin release to a level which reached statistical significance in an incubation medium containing no glucose. In medium containing 1·5 mg. glucose/ml., arginine, isoleucine, leucine and lysine stimulated insulin release and phenylalanine inhibited insulin release. Glucagon, theophylline or dibutyryl cyclic adenosine monophosphate stimulated insulin release significantly in the presence of leucine but not in the presence of arginine. Arginine stimulated insulin release in the presence of leucine. The results of these experiments characterize further the difference in the mechanism of action of leucine and arginine on the pancreatic β-cell and indicate possible explanations for results obtained in other species in vivo.

Influence of nicotinic acid on insulin release in vitro

1972 ◽  
Vol 9 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Hans-Jürgen Hahn ◽  
Rainer Michael
Keyword(s):  
Nicotinic Acid ◽  
Insulin Release ◽  
Release In Vitro
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