RESUMEN
Hypertriglyceridemia (HTG) is one of the key features of dyslipidemia in type 2 diabetes, caused by the overproduction and/or decreased clearance of triglyceride (TG)-rich lipoproteins, and significantly promotes the development of cardiovascular diseases in diabetes. However, the effect of severe HTG on glucose metabolism has not previously been determined. Lipoprotein lipase (LPL) deficiency results in severe HTG in humans. By using LPL-deficient mice with severe HTG, we assessed the impact of severe HTG on insulin secretion and glucose tolerance in the present study. While young LPL-deficient mice (4 months of age) showed higher fasting blood glucose (7.42 +/- 0.84 versus 4.8 +/- 0.80 mmol/L, P < 0.01) and lower insulin concentrations (0.16 +/- 0.03 versus 0.48 +/- 0.14 ng/mL, P < 0.05), old mice (12 months of age) had higher insulin (1.70 +/- 0.35 versus 0.77 +/- 0.04 ng/mL, P < 0.05) but normal fasting blood glucose concentrations. Both young and old mice had elevated free fatty acid (FFA) concentrations and exhibited decreased early insulin response; however, only old mice showed impaired glucose tolerance, as compared with wild-type mice of a similar age. Morphological assessment showed enlarged islets in old LPL-deficient mice. These findings suggest that different tests for glucose homeostasis may be needed for patients with LPL deficiency and severe HTG, even though their glucose concentrations are normal at initial screening.
Asunto(s)
Intolerancia a la Glucosa/fisiopatología , Hipertrigliceridemia/fisiopatología , Insulina/metabolismo , Animales , Glucemia/metabolismo , Modelos Animales de Enfermedad , Femenino , Intolerancia a la Glucosa/sangre , Humanos , Hiperlipoproteinemia Tipo IV/genética , Hiperlipoproteinemia Tipo IV/fisiopatología , Hipertrigliceridemia/sangre , Hipertrigliceridemia/patología , Insulina/sangre , Secreción de Insulina , Lipoproteína Lipasa/deficiencia , Lipoproteína Lipasa/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Páncreas/patologíaRESUMEN
In order to understand the mechanism of the interaction of sulfate polysaccharides and small molecules at molecular level, the structure of pachymaran was decorated by Wolfrom, and sulfation pachymaran (SP) was prepared. The maximum binding number (N = 54) and the binding equilibrium constant (K = 1.563 x 10(6)) of the sulfation pachymaran and methylene blue (MB) were obtained by the exoterica model. The influence of the molar ratio of MB/SP, ethanol, hydroxypropyl-beta-cyclodextrin, Triton X-100 and NaCl on the spectra of MB-SP complex was investigated. The mechanism of the color changes of methylene blue and sulfation pachymaran reaction system has been discussed. The authors draw the conclusion that the color changes result mainly from the hydrophobic interaction between methylene blue molecules binding on sulfation pachymaran on the base of the electrostatic interaction of methylene blue and sulfation pachymaran.
Asunto(s)
Glucanos/química , Azul de Metileno/química , Espectrofotometría/métodos , 2-Hidroxipropil-beta-Ciclodextrina , Unión Competitiva , Combinación de Medicamentos , Etanol/química , Cinética , Estructura Molecular , Octoxinol/química , Cloruro de Sodio/química , Sulfamonometoxina , Trimetoprim , beta-Ciclodextrinas/químicaRESUMEN
A simple, accurate and rapid spectrophotmeric method was proposed for the determination of chondroitin sulfate. The method was based on the absorbances of AA-CS complex at 625 nm being in proportion to the chondroitin sulfate concentrations. The linear range was 0-30 micrograms.mL-1 (R = 0.999), and the recovery range was 97.4%-103.8%. The quantities of chondroitin sulfate in different sample were determined in this way.