Serum homocysteine, arginine, citrulline and asymmetric dimethyl arginine levels, and histopathologic examination of the abdominal aorta in rats exposed to acrylamide

Gestational exposure to acrylamide suppresses luteal endocrine function through dysregulation of ovarian angiogenesis, oxidative stress and apoptosis in mice

The discovery of acrylamide in various carbohydrate-rich foods cooked at high temperatures has attracted public health concerns. This study aimed to elucidate the effects and mechanisms additional with acrylamide exposure on the luteal function in vivo during early- and mid-pregnancy. Mice were fed with different dosages of acrylamide (0, 10 and 50 mg/kg/day) by gavage from gestational days (GD) 3 to GD 8 or GD 13. The results indicated that acrylamide exposure significantly decreased levels of serum progesterone and estradiol, and the numbers and relative areas of ovarian corpora lutea. The expression levels of Hsd3b1, Cyp11a1 and Star mRNA markedly reduced in acrylamide-treated ovaries. Furthermore, acrylamide exposure obviously suppressed the activities of catalase and superoxide dismutase, but increased the levels of H₂O₂ and malondialdehyde. Additionally, acrylamide treatment significantly inhibited luteal angiogenesis and induced the apoptosis of ovarian cells by up-regulation of P53 and Bax protein and down-regulation of Bcl-2 protein. Thus, our results showed that gestational exposure to acrylamide significantly inhibited luteal endocrine function via dysregulation of ovarian angiogenesis, oxidative stress and apoptosis in vivo.

Effects of acrylamide on oxidant/antioxidant parameters and CYP2E1 expression in rat pancreatic endocrine cells

Oxidative stress is one of the principle mechanism of acrylamide-induced toxicity. Acrylamide is metabolized by cytochrome P450 2E1 (CYP2E1) to glycidamide or by direct conjugation with glutathione. Bearing in mind that up to now the effects of acrylamide on oxidative stress status and CYP2E1 level in endocrine pancreas have not been studied we performed qualitative and quantitative immunohistochemical evaluation of inducible nitric oxide synthase (iNOS), superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), catalase (CAT) and CYP2E1 expression in islets of Langerhans of rats subchronically treated with 25 or 50mg/kg bw of acrylamide. Since the majority of cells (>80%) in rodent islets are beta cells, in parallel studies, we employed the Rin-5F beta cell line to examine effects of acrylamide on redox status and the activity of CAT, SOD and glutathione-S-transferase (GST), their gene expression, and CYP2E1, NF-E2 p45-related factor 2 (Nrf2) and iNOS expression. Immunohistochemically stained pancreatic sections revealed that acrylamide induced increase of iNOS and decrease of CYP2E1 protein expression, while expression of antioxidant enzymes was not significantly affected by acrylamide in islets of Langerhans. Analysis of Mallory-Azan stained pancreatic sections revealed increased diameter of blood vessels lumen in pancreatic islets of acrylamide-treated rats. Increase in the GST activity, lipid peroxidation and nitrite level, and decrease in GSH content, CAT and SOD activities was observed in acrylamide-exposed Rin-5F cells. Level of mRNA was increased for iNOS, SOD1 and SOD2, and decreased for GSTP1, Nrf2 and CYP2E1 in acrylamide-treated Rin-5F cells. This is the first report of the effects of acrylamide on oxidant/antioxidant parameters and CYP2E1 expression in pancreatic endocrine cells.

Asymmetric Dimethylarginine in Patients with Ascending Aortic Aneurysms

BACKGROUND

Ascending thoracic aortic aneurysm (aTAA) is a heterogeneous group of disorders that involve impaired endothelial function. The nitric oxide (NO) synthase inhibitor asymmetric dimethylarginine (ADMA) serves as an endothelial dysfunction marker. Thus, we investigated ADMA levels in patients with aTAA.

METHODS

Eighty-six patients with aTAA and 18 healthy individuals were enrolled. All patients underwent echocardiography. Plasma ADMA levels were measured using high-performance liquid chromatography.

RESULTS

ADMA levels were higher in aTAA patients than in control patients (p = 0.034). According to the multivariable regression model, higher ADMA levels were associated with ascending aortic diameter (p = 0.017), smoking (p = 0.016), and log-transformed estimated glomerular filtration rate (eGFR, p = 0.005).

CONCLUSION

This pilot study demonstrates an association of ADMA with ascending aortic dilatation; however, further studies are needed to investigate whether increased ADMA levels underlie aTAA development.

Heated vegetable oils and cardiovascular disease risk factors

Cardiovascular disease (CVD) is one of the leading major causes of morbidity and mortality worldwide. It may result from the interactions between multiple genetic and environmental factors including sedentary lifestyle and dietary habits. The quality of dietary oils and fats has been widely recognised to be inextricably linked to the pathogenesis of CVD. Vegetable oil is one of the essential dietary components in daily food consumption. However, the benefits of vegetable oil can be deteriorated by repeated heating that leads to lipid oxidation. The practice of using repeatedly heated cooking oil is not uncommon as it will reduce the cost of food preparation. Thermal oxidation yields new functional groups which may be potentially hazardous to cardiovascular health. Prolonged consumption of the repeatedly heated oil has been shown to increase blood pressure and total cholesterol, cause vascular inflammation as well as vascular changes which predispose to atherosclerosis. The harmful effect of heated oils is attributed to products generated from lipid oxidation during heating process. In view of the potential hazard of oxidation products, therefore this review article will provide an insight and awareness to the general public on the consumption of repeatedly heated oils which is detrimental to health.