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Abstract: Hyperglycemia-induced generation of reactive oxygen species contributes to the development of proatherogenic changes and vasculopathy in diabetes. NADPH oxidase has been recognized as a major source of reactive oxygen species in the vasculature and the lectin-like oxLDL receptor-1 (LOX-1) appears to play a crucial role in the pathogenesis of diabetic endothelial dysfunction. The present study aimed to examine the relationships between the hyperglycemia-mediated NADPH oxidase-LOX-1 pathway activation and nitric oxide-mediated endothelial function. In addition, we investigated effect of the NADPH oxidase inhibitor, apocynin on these consequences. In human umbilical artery endothelial cells (HUAECs), the effect of high glucose on expressional regulations and functional consequences of NADPH oxidase subunits, LOX-1 and endothelial nitric oxide synthase (eNOS), in the absence and presence of apocynin (10µmol/l) were evaluated. HUAECs were cultured under normal (5.5mmol/l) or high glucose (30mmol/l) concentrations for 48h in the absence and presence of apocynin. Our results showed that high glucose significantly enhanced the activity and the protein expression of NADPH oxidase subunits, Nox2 and p47phox. High glucose markedly increased LOX-1 mRNA level and this was functionally reflected on the augmented uptake of Dil-labelled LDL (5µmol/l, 3h) by HUAECs. Furthermore, high glucose attenuated eNOS protein and total nitrite levels. However, apocynin inhibited all these changes. Collectively, our study demonstrates that high glucose-induced oxidative stress via NADPH oxidase activation and this contributed to LOX-1 upregulation and eNOS downregulation in human endothelial cells. Apocynin efficiently reversed these consequences, suggesting its potential role as a vasculoprotective agent. [Copyright &y& Elsevier]

In guinea pig antral mucous cells, ACh stimulates the Ca2+-regulated exocytosis, which has a characteristics feature: an initial transient phase followed by a sustained phase. The effects of cGMP on ACh-stimulated exocytosis were studied in guinea pig antral mucous cells using video microscopy. cGMP enhanced the frequency of ACh-stimulated exocytotic events, whereas cGMP alone did not induce any exocytotic events under the ACh-unstimulated condition. cGMP did not stimulate either Ca2+ mobilization or cAMP accumulation. The Ca2+ dose-response studies demonstrated that cGMP shifted the dose-response curve upward with no shift to the lower concentration. This indicates that cGMP increased maximal responsiveness of the Ca2+-regulated exocytosis, but not the Ca2+ sensitivity. Moreover, under a condition of ATP depletion by dinitrophenol (DNP) or anoxia (N2 bubbling), ACh evoked only a sustained phase in exocytotic events with no initial transient phase. However, ACh evoked an initial transient phase followed by a sustained phase with addition of cGMP before ATP depletion, whereas only a sustained phase was evoked in a case of cGMP addition after ATP depletion. Thus cGMP-induced enhancement in ACh-stimulated exocytotic events requires ATP, suggesting that cGMP modulates ATP-dependent priming of Ca2+-regulated exocytosis in antral mucous cells. In conclusion, cGMP increases the number of primed granules via acceleration of the ATP-dependent priming, which enhances the Ca2+-regulated exocytosis stimulated by ACh. [ABSTRACT FROM AUTHOR]

This study examined the dietary effects of Sanacore®GM (SAN) on growth and production, immune-antioxidative status, cytokines, and the resistance of European sea bass to Vibrio alginolyticus infection. Fish (28.5–32.3 g) were fed on 0.0, 1.0, 2.0, 4.0, 6.0, and 8.0 g SAN/kg feed for ten weeks. Following that, fish were intraperitoneally injected with V. alginolyticus, and observed for further ten days. Among different water quality parameters, only unionized ammonia and nitrite values were significantly declined in groups received 4.0–8.0 g SAN/kg feed. Significant increases in fish growth, production, hematological, and immune-antioxidant indices were observed in SAN-fed fish. Compared with the control group, IL-1β and TNF-α genes expressions were down-regulated in groups fed on 4.0–8.0 g SAN/kg feed. After bacterial infection, low fish mortalities (20%–10%) were observed in fish fed with 4.0–8.0 g SAN/feed, respectively. The polynomial fitting curve demonstrates that the optimum SAN level for European sea bass is 5.0 g/kg feed. [ABSTRACT FROM AUTHOR]

Background: The present study is designed to assess the effect of adding various doses of Spirulina platensis (SP) on broiler chicken growth performance, gut health, antioxidant biomarkers, cecal microbiota, histopathology, and immunohistochemistry of inducible nitric oxide synthase (iNOS). 240 male Cobb 500 broiler chicks (1 day old) were placed into four groups (sixty birds/group), then each group was further divided into three replicates of 20 chickens each for 35 days. Birds were allocated as follows; the 1st group (G1), the control group, fed on basal diet, the 2nd group (G2): basal diet plus SP (0.1%), the 3rd group (G3): basal diet plus SP (0.3%), and the 4th group (G4): basal diet plus SP (0.5%). Results: Throughout the trial (d 1 to 35), SP fortification significantly increased body weight growth (BWG) and feed conversion rate (FCR) (P < 0.05). Bursa considerably increased among the immunological organs in the Spirulina-supplemented groups. Within SP-supplemented groups, there was a substantial increase in catalase activity, blood total antioxidant capacity, jejunal superoxide dismutase (SOD), and glutathione peroxidase (GPX) activity (P < 0.05). Fatty acid binding protein 2 (FABP2), one of the gut barrier health biomarkers, significantly increased in the SP-supplemented groups but the IL-1β gene did not significantly differ across the groups (P < 0.05). Different organs in the control group showed histopathological changes, while the SP-supplemented chicken showed fewer or no signs of these lesions. The control group had higher levels of iNOS expression in the gut than the SP-supplemented groups (p < 0.05). Cecal Lactobacillus count significantly elevated with increasing the rate of SP inclusion rate (p < 0.05). Conclusion: Supplementing broiler diets with SP, particularly at 0.5%, can improve productivity and profitability by promoting weight increase, feed utilization, antioxidant status, immunity, and gastrointestinal health. [ABSTRACT FROM AUTHOR]

Indomethacin (IDM, 10 μm), not aspirin (ASA; 10 μm), enhanced the Ca2+-regulated exocytosis stimulated by 1 μm acetylcholine (ACh) in guinea-pig antral mucous cells. Indomethacin inhibits prostaglandin G/H (PGG/H) and 15 R-hydroperoxy-eicosatetraenoic acid (15R-HPETE) production from arachidonic acid (AA), while ASA inhibits PGG/H production but accelerates 15R-HPETE production. This suggests that IDM accumulates AA. Arachidonic acid (2 μm) enhanced Ca2+-regulated exocytosis in antral mucous cells to a similar extent to IDM. Moreover, a stable analogue of AA, arachidonyltrifluoromethyl ketone (AACOCF3), also enhanced Ca2+-regulated exocytosis, indicating that AA, not products from AA, enhances Ca2+-regulated exocytosis. We hypothesized that AA activates peroxisome proliferation activation receptor α (PPARα), because AA is a natural ligand for PPARα. A PPARα agonist (WY14643; 1 μm) enhanced Ca2+-regulated exocytosis, and a PPARα blocker (MK886; 50 μm) abolished the enhancement of Ca2+-regulated exocytosis induced by AA, IDM, AACOCF3 and WY14643. Western blotting and immunohistochemical examinations demonstrated that PPARα exists in antral mucous cells. Moreover, MK886 decreased the frequency of Ca2+-regulated exocytosis activated by 1 μm ACh or 2 μm thapsigargin alone by 25–30%. Thus, ACh stimulates AA accumulation via an [Ca2+]i increase, which activates PPARα, leading to enhancement of Ca2+-regulated exocytosis in antral mucous cells. A novel autocrine mechanism mediated via PPARα enhances Ca2+-regulated exocytosis in guinea-pig antral mucous cells. [ABSTRACT FROM AUTHOR]