In order to explore the method to prepare hypoxia UW solution and the stability and preservation of hypoxia UW solution, UW solution was purged by argon or air for 15 min or 60 at a flow rate of 0.8 or 2 L/min, and the oxygen partial pressure of UW solution was detected. The hypoxia UW solution was exposed to the air or sealed up to preserve by using different methods, and the changes of oxygen partial pressure was tested. The results showed that oxygen partial presure of 50 mL UW solution, purged by argon for 15 min at a flow rate of 2 L/min, was declined from 242+/-6 mmHg to 83+/-10 mmHg. After exposure to the air, oxygen partial pressure of hypoxia UW solution was gradually increased to 160+/-7 mmHg at 48 h. After sealed up by the centrifuge tube and plastic bad filled with argon, oxygen partial pressure of hypoxia UW solution was stable, about 88+/-13 mmHg at 72 h. It was concluded that oxygen of UW solution could be purged by argon efficiently. Sealed up by the centrifuge tube and plastic bag filled with argon, oxygen partial pressure of UW solution could be stabilized.
Adenosine/chemical synthesis ; Allopurinol/chemical synthesis ; Anoxia ; Glutathione/chemical synthesis ; Insulin/chemical synthesis ; Organ Preservation/*methods ; Organ Preservation Solutions/*chemical synthesis ; Oxygen/*analysis ; Partial Pressure ; Raffinose/chemical synthesis

Animals ; Cattle ; Crystallization ; Insulin ; chemical synthesis ; chemistry ; Protein Structure, Secondary

AIMTo find new peroxisome proliferator-activated y agonists with high activity and low toxicity.

METHODSBased on JTT-501 and JTT-20993, new isoxazolidine-3,5-dione and noncyclic 1,3-dicarbonyl compounds were designed and synthesized. Their insulin-sensitizing activities were evaluated.

RESULTSEight new compounds were obtained. The structures of synthesized compounds were characterized by NMR, MS and IR. Four compounds (1A-4A) showed insulin-sensitizing activities.

CONCLUSIONCompounds (1A and 3A) showed excellent insulin-sensitizing activities and should be worth further investigation.

3T3-L1 Cells ; Animals ; Glucose ; metabolism ; Hypoglycemic Agents ; agonists ; chemical synthesis ; pharmacology ; Insulin ; pharmacology ; Isoxazoles ; chemical synthesis ; pharmacology ; Mice ; PPAR gamma ; agonists ; chemical synthesis ; pharmacology

Ten novel compounds were designed and synthesized on the basis of compound 1, their insulin-sensitizing activities were evaluated in 3T3-L1 cells. Results showed that compound 10 exhibited strong differentiation-stimulating activity on 3T3-L1 cells model, which indicated that compound 10 may possess well insulin-sensitizing activity.
3T3-L1 Cells ; Animals ; Benzopyrans ; chemical synthesis ; pharmacology ; Drug Design ; Hypoglycemic Agents ; chemical synthesis ; pharmacology ; Insulin ; pharmacology ; Mice

Chitosan microsphere has been wildly researched in controlled release of protein and peptide drug because of its excellent mucoadhesive and permeation enhancing effect across the biological surfaces. The control of the size and size distribution of microspheres is necessary in order to improve reproducibility, bioavailability, and repeatable release behavior. In this work, uniform-sized chitosan microspheres containing insulin were prepared by a novel membrane emulsification technique combined with glutaraldehyde crosslinking method. In order to prepare uniform-sized chitosn microspheres, it is necessary to modify hydrophilic membrane into hydrophobicity. It is found that there exists a linear relationship between the size of chitosan microspheres and pore size of the membrane used, so it is easy to control the size of microspheres by using membranes with different pore size. In this study, the effect of different amount of crosslinker and crosslinking time on microspheres' morphology, encapsulation efficiency (EE) and release profile of drug in vitro were investigated. It is shown that the morphology of microspheres is more smooth and spherical, and the release rate is slower with the increase of amount of glutaraldehyde and prolongation of crosslinking time. When the molar ratio of amino group of chitosan to aldehyde group of glutaraldehyde is 1:0.7, and crosslinking time is 1 h, the highest EE was obtained (about 65%). Date obtained suggest that chitosan microspheres prepared by this new method would be a promising system for controlled release of protein drugs.
Biocompatible Materials ; chemistry ; Chitosan ; chemistry ; Cross-Linking Reagents ; Delayed-Action Preparations ; chemical synthesis ; Drug Carriers ; chemical synthesis ; Emulsions ; Glutaral ; chemistry ; Humans ; Insulin ; pharmacokinetics ; Microspheres ; Particle Size

AIMTo design and synthesize new phenyloxyisobutyric acid analogues as antidiabetic compounds.

METHODSEight new target compounds were synthesized by combination of lipophilic moieties and acidic moiety with nucleophilic replacement or Mitsunobu condensation. The eight compounds were confirmed by 1H NMR, 13C NMR, IR and MS.

RESULTSIn vitro insulin-sensitizing activity (3T3-L1 adipocyte) demonstrated, that the cultured glucose concentration of up-clear solution detected with GOD-POD assay were 5.942, 6.339, 6.226 and 6.512 mmol x L(-1), respectively, when rosiglitazone, pioglitazone, compounds A and B were added to the insulin-resistant system.

CONCLUSIONIn vitro insulin-sensitizing activity of target compound A is in between that of rosiglitazone and pioglitazone, and activity of target compound B is slightly less than that of pioglitazone.

3T3-L1 Cells ; Adipocytes ; drug effects ; Animals ; Butyrates ; chemical synthesis ; chemistry ; pharmacology ; Hypoglycemic Agents ; chemical synthesis ; chemistry ; pharmacology ; Insulin ; pharmacology ; Mice ; Molecular Structure ; PPAR gamma ; agonists ; pharmacology

AIMTo design and synthesize compounds with insulin-sensitizing activity.

METHODSUsing association principle of drug design, ten title compounds were designed and synthesized on the basis of known compounds with insulin-sensitizing activity, and their insulin-sensitizing activity were evaluated on 3T3-L1 pre-adipocyte cells.

RESULTSOne of the synthesized compounds showed strong insulin-sensitizing activity in vitro.

CONCLUSIONThis compound may possess good sugar-lowering activity, and will be chosen for further hypoglycemic evaluation in vivo.

3T3-L1 Cells ; metabolism ; Adipocytes ; drug effects ; Animals ; Drug Design ; Hypoglycemic Agents ; chemical synthesis ; pharmacology ; Indoles ; chemical synthesis ; pharmacology ; Insulin ; pharmacology ; Mice ; Triglycerides ; metabolism

The purpose of the study is to investigate the effect of 8-hydroxy-dihydroberberine on insulin resistance induced by high free fatty acid (FFA) and high glucose in 3T3-L1 adipocytes and its possible molecular mechanism. Palmic acid or glucose in combination with insulin was used to induce insulin resistance in 3T3-L1 adipocytes. 8-Hydroxy-dihydroberberine and berberine were added to the cultured medium separately, which were considered as treated group and positive control group. The rate of glucose uptake was determined by 2-deoxy-[3H]-D-glucose method. The amount of glucose consumption in the medium was measured by glucose oxidase method. Cell growth and proliferation of 3T3-L1 adipocytes were detected with Cell Counting Kit-8 (CCK-8) assay. After incubated with palmic acid for 24 hours or glucose with insulin for 18 hours, the rate of glucose transport in 3T3-L1 adipocytes was inhibited by 67% and 58%, respectively. The amount of glucose consumption in 3T3-L1 adipose cells was decreased by 41% after cells were incubated with palmic acid for 24 h. However, the above changes were reversed by pretreatment with 8-hydroxy-dihydroberberine for 24 and 48 h. Significant difference existed between groups. Insulin resistance in 3T3-L1 adipocytes, which is induced by high FFA and high glucose, could be ameliorated by 8-hydroxy-dihydroberberine.
3T3-L1 Cells ; Adipocytes ; cytology ; drug effects ; metabolism ; Animals ; Berberine ; analogs & derivatives ; chemical synthesis ; chemistry ; pharmacology ; Cell Differentiation ; drug effects ; Glucose ; metabolism ; pharmacology ; Hypoglycemic Agents ; chemical synthesis ; chemistry ; pharmacology ; Insulin ; pharmacology ; Insulin Resistance ; Mice ; Molecular Structure ; Palmitic Acid ; pharmacology

OBJECTIVETo investigate various methods for constructing soybean lecithin (SL)-based vesicles and evaluate the permeation-enhancing effect of SL-based vesicles on the penetration of insulin through buccal mucosa.

METHODSThe ultrasonic method, high speed shear method and high pressure homogenization method were respectively used to prepare the SL-based vesicles, and the particle size of the vesicles was measured with photon correlation spectrometry (PCS). The penetration rate of insulin through porcine buccal mucosa was investigated with the Valia-Chien diffusion cells.

RESULTSThe average particle sizes of 3 formulations of SL-based vesicles were 97.39, 85.60, and 100.60 nm when prepared by ultrasonic method, and were 58.7, 88.7, and 91.9 nm when prepared by high pressure homogenization method. Both vesicles presented good stability. However, the SL-based vesicles prepared by high speed shear method had larger average diameters and were found to be unstable. Transmission electron microscopy showed that SL-based vesicles had a spherical shape and the result accorded with PCS. The permeation flux of insulin of formulation 1 and control solution were 0.0024 and 0.0008 IU x ml(-1) x min(-1), respectively. The accumulative amount of formulation 1 at 180 min was (0.436 +/- 0.010 ) IU x ml(-1), which was 1.46 times higher than the control solution.

CONCLUSIONSThe SL-based vesicles obtained using high pressure homogenization method are characterized by small particle size, narrow distribution, good stability, and powerful permeation-enhancing effect, which enables them to be good carriers for the buccal delivery of insulin.

Absorption ; Administration, Topical ; Chemistry, Pharmaceutical ; Drug Carriers ; administration & dosage ; chemical synthesis ; pharmacokinetics ; Drug Delivery Systems ; methods ; Insulin ; metabolism ; Mouth Mucosa ; metabolism ; Nanotechnology ; methods ; Phosphatidylcholines ; pharmacokinetics ; Soybeans ; chemistry

Kv2.1 channel currents in pancreatic beta-cells are thought to contribute to action potential repolarization and thereby modulate insulin secretion. Because of its central role in this important physiological process, Kv2.1 channel is a promising target for the treatment of type 2 diabetes. Jingzhaotoxin-XI (JZTX-XI) is a novel peptide neurotoxin isolated from the venom of the spider Chilobrachys jingzhao. Two-microelectrode voltage clamp experiments had showed that the toxin inhibited Kv2.1 potassium currents expressed in Xenopus Laevis oocytes. In order to investigate the structure-function relationship of JZTX-XI, the natural toxin and a mutant of JZTX-XI in which Arg3 was replaced by Ala, were synthesized by solid-phase chemistry method with Fmoc-protected amino acids on the PS3 automated peptide synthesizer. Reverse-phase high performance liquid chromatography (RP-HPLC) and matrix assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) were used to monitor the oxidative refolding process of synthetic linear peptides to find the optimal renaturation conditions of these toxins. The experiments also proved that the relative molecular masses of refolded peptides were in accordance with their theoretical molecular masses. RP-HPLC chromatogram of co-injected native and refolded JZTX-XI was a single peak. Under the whole-cell patch-clamp mode, JZTX-XI could completely inhibit hKv2.1 and hNav1.5 channels currents expressed in HEK293T cells with IC50 values of 95.8 nmol/L and 437.1 nmol/L respectively. The mutant R3A-JZTX-XI could also inhibit hKv2.1 and hNav1.5 channel currents expressed in HEK293T cells with IC50 values of 1.22 micromol/L and 1.96 micromol/L respectively. However, the prohibitive levels of R3A-JZTX-XI on hKv2.1 and hNav1.5 channels were reduced by about 12.7 times and 4.5 times respectively, indicating that Arg3 was a key amino acid residue relative to the hKv2.1 channel activity of JZTX-XI, but it is also an amino acid residue correlated with the binding activity of JZTX-XI to hNav1.5 channel. Our findings should be helpful to develop JZTX-XI into a molecular probe and drug candidate targeting to Kv2.1 potassium channel in the pancreas.
Animals ; HEK293 Cells ; Humans ; Insulin-Secreting Cells ; metabolism ; Mutant Proteins ; genetics ; pharmacology ; NAV1.5 Voltage-Gated Sodium Channel ; metabolism ; Neurotoxins ; chemical synthesis ; genetics ; pharmacology ; Protein Refolding ; Shab Potassium Channels ; antagonists & inhibitors ; metabolism ; Sodium Channel Blockers ; pharmacology ; Spider Venoms ; genetics ; pharmacology ; Transfection