Early alterations in vascular contractility associated to changes in fatty acid composition and oxidative stress markers in perivascular adipose tissue

<p>Abstract</p> <p>Aim</p> <p>To test the early effect of fructose-induced changes in fatty acid composition and oxidative stress markers in perivascular adipose tissue (PVAT) upon vascular contractility.</p> <p>Methods</p> <p>Adult male Wistar rats were fed a commercial diet without (CD) or with 10% fructose (FRD) in the drinking water for 3 weeks. We measured plasma metabolic parameters, lipid composition and oxidative stress markers in aortic PVAT. Vascular contractility was measured in aortic rings sequentially, stimulated with serotonin (5-HT) and high K⁺-induced depolarization using intact and thereafter PVAT-deprived rings.</p> <p>Results</p> <p>Comparable body weights were recorded in both groups. FRD rats had increased plasma triglyceride and fructosamine levels. Their PVAT had an increased saturated to mono- or poly-unsaturated fatty acid ratio, a significant decrease in total superoxide dismutase and glutathione peroxidase activities and in the total content of glutathione. Conversely, lipid peroxidation (TBARS), nitric oxide content, and gluthathione reductase activity were significantly higher, indicating an increase in oxidative stress. In aortic rings, removal of PVAT increased serotonin-induced contractions, but the effect was significantly lower in rings from FRD rats. This effect was no longer observed when the two contractions were performed in PVAT-deprived rings. PVAT did not affect the contractions triggered by high K⁺-induced depolarization either in CD or FRD rats.</p> <p>Conclusions</p> <p>FRD induces multiple metabolic and endocrine systemic alterations which also alter PVAT and the vascular relaxant properties of this tissue. The changes in PVAT would affect its paracrine modulation of vascular function.</p

Effect of Pioglitazone on the Fructose-Induced Abdominal Adipose Tissue Dysfunction

Aim. To test the potential role of PPARγ in the endocrine abdominal tissue dysfunction induced by feeding normal rats with a fructose rich diet (FRD) during three weeks. Methodology. Adult normal male rats received a standard commercial diet (CD) or FRD, (10% in drinking water) without or with pioglitazone (PIO) (i.p. 0.25mg/Kg BW/day; CD-PIO and FRD-PIO). Thereafter, we measured circulating metabolic, endocrine, and oxidative stress (OS) markers, abdominal adipose tissue (AAT) mass, leptin (LEP) and plasminogen activator inhibitor-1 (PAI-1) tissue content/expression, and leptin release by isolated adipocytes incubated with different concentrations of insulin. Results. Plasma glucose, insulin, triglyceride, TBARS, LEP, and PAI-1 levels were higher in FRD rats; PIO coadministration fully prevented all these increments. AAT adipocytes from FRD rats were larger, secreted a higher amount of LEP, and displayed decreased sensitivity to insulin stimulation; these effects were significantly ameliorated by PIO. Whereas AAT LEP and PAI-1 (mRNA) concentrations increased significantly in FRD rats, those of insulin-receptor-substrate- (IRS-) 1 and IRS-2 were reduced. PIO coadministration prevented FRD effects on LEP, PAI-1, and IRS-2 (fully) and IRS-1 (partially) mRNAs in AAT. Conclusion. PPARγ would play a relevant role in the development of the FRD-induced metabolicendocrine dysfunction

Use of the entomopathogenic fungi \u3ci\u3eMetarhizium anisopliae, Cordyceps bassiana\u3c/i\u3e and \u3ci\u3eIsaria fumosorosea\u3c/i\u3e to control \u3ci\u3eDiaphorina citri\u3c/i\u3e (Hemiptera: Psyllidae) in Persian lime under field conditions

The Asian citrus psyllid Diaphorina citri Kuwayama is a destructive insect pest in citriculture, because it is an efficient vector of the proteobacteria ‘Candidatus Liberibacter asiaticus’ (Las), ‘Ca. L. africanus’ (Laf) and ‘Ca. L. americanus’ (Lam). These bacteria cause the ‘huanglongbing’ disease or ‘greening’ or ‘yellow dragon’ disease. The disease kills the plant and reduces fruit production. This insect pest is susceptible to entomopathogenic fungi, and we report the use of different strains of Metarhizium anisopliae, Cordyceps bassiana and Isaria fumosorosea against the nymphs and adults of D. citri under field conditions. The fungi were applied four times using a concentration of 2 £ 1013 conidia/ha with a time interval of 15 days between applications. The percentage of control of Cb 108, Ma 65, Ma 14 and Ifr 4 was 60, 50, 40 and 35% in nymphs, and 50, 50, 42 and 22% in adults, respectively. Metarhizium anisopliae, C. bassiana and I. fumosorosea applied on Persian lime groves are more effective in reducing higher density of nymphs than adults of D. citri

Sitagliptin prevents the development of metabolic and hormonal disturbances, increased β-cell apoptosis and liver steatosis induced by a fructose-rich diet in normal rats

The aim of the present study was to test the effect of sitagliptin and exendin-4 upon metabolic alterations, β-cell mass decrease and hepatic steatosis induced by F (fructose) in rats. Normal adult male Wistar rats received a standard commercial diet without (C) or with 10% (w/v) F in the drinking water (F) for 3 weeks; animals from each group were randomly divided into three subgroups: untreated (C and F) and simultaneously receiving either sitagliptin (CS and FS; 115.2 mg/day per rat) or exendin-4 (CE and FE; 0.35 nmol/kg of body weight, intraperitoneally). Water and food intake, oral glucose tolerance, plasma glucose, triacylglycerol (triglyceride), insulin and fructosamine concentration, HOMA-IR [HOMA (homoeostasis model assessment) for insulin resistance], HOMA-β (HOMA for β-cell function) and liver triacylglycerol content were measured. Pancreas immunomorphometric analyses were also performed. IGT (impaired glucose tolerance), plasma triacylglycerol, fructosamine and insulin levels, HOMA-IR and HOMA-β indexes, and liver triacylglycerol content were significantly higher in F rats. Islet β-cell mass was significantly lower in these rats, due to an increase in the percentage of apoptosis. The administration of exendin-4 and sitagliptin to F animals prevented the development of all the metabolic disturbances and the changes in β-cell mass and fatty liver. Thus these compounds, useful in treating Type 2 diabetes, would also prevent/delay the progression of early metabolic and tissue markers of this disease.Fil: Maiztegui, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Borelli, Maria Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Madrid, Viviana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: del Zotto, Hector Herminio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Raschia, Maria Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Francini, Flavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Massa, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Flores, Luis Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Rebolledo, Oscar R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); Argentin

Fructose-rich diet-induced abdominal adipose tissue endocrine dysfunction in normal male rats.

We have currently studied the changes induced by administration of a fructose-rich diet (FRD) to normal rats in the mass and the endocrine function of abdominal (omental) adipose tissue (AAT). Rats were fed ad libitum a standard commercial chow and tap water, either alone (control diet, CD) or containing fructose (10%, w/vol) (FRD). Three weeks after treatment, circulating metabolic markers and leptin release from adipocytes of AAT were measured. Plasma free fatty acids (FFAs), leptin, adiponectin, and plasminogen activator inhibitor-1 (PAI-1) levels were significantly higher in FRD than in CD rats. AAT mass was greater in FRD than in CD rats and their adipocytes were larger, they secreted more leptin and showed impaired insulin sensitivity. While leptin mRNA expression increased in AAT from FRD rats, gene expression of insulin receptor substrate, IRS1 and IRS2 was significantly reduced. Our study demonstrates that administration of a FRD significantly affects insulin sensitivity and several AAT endocrine/metabolic functions. These alterations could be part of a network of interacting abnormalities triggered by FRD-induced oxidative stress at the AAT level. In view of the impaired glucose tolerance observed in FRD rats, these alterations could play a key role in both the development of metabolic syndrome (MS) and beta-cell failure