Summary We examined the effect in rats of 2 months of streptozotocin-induced diabetes mellitus on relaxation and contraction of aortas in vitro. A further diabetic group was treated from time of diabetes induction with a 1% dietary supplement of vitamin E. Diabetes caused a 26.5% deficit (p<0.001) in maximum endothelium-dependent relaxation to acetylcholine in phenylephrine-precontracted aortas. This was 64.3% attenuated (p<0.01) by vitamin E treatment; maximum relaxation was not significantly altered compared to non-diabetic rats. Vitamin E treatment of non-diabetic rats did not significantly affect acetylcholine-induced relaxation. Diabetes or treatment did not significantly alter acetylcholine sensitivity. Endothelium-independent relaxation response to glyceryl trinitrate was not affected by diabetes or vitamin E treatment, indicating that vascular smooth muscle responses to nitric oxide remained unaltered. There was a 35.4% reduction in the maximum contractile response to phenylephrine with diabetes (p<0.05) which was unaffected by vitamin E treatment. The data suggest that the chronic deficit in nitric oxide-mediated endothelium-dependent relaxation in diabetes depends largely upon excess activity of reactive oxygen species. Treatment with vitamin E to increase free radical scavenging specifically protected vascular endothelium although it had no effect on deficits in vascular smooth muscle contractile responses.Abbreviations NO
Nitric oxide
- ARI
aldose reductase inhibitor
- ACH
acetylcholine
- GTN
glyceryl trinitrate
- GSH
reduced form of glutathione
- EC50
effective concentration for 50% of the maximal response 相似文献
A 72-year-old fisherman who was positive for the HCV antibody developed an annular, erythematous, infiltrated lesions on sun-exposed areas. The lesions were diagnosed as annular elastolytic giant cell granuloma both clinically and histologically. Topical corticosteroid and cryotherapy with liquid nitrogen for several months failed to improve the lesions. We then started dapsone, a known anti-oxidant, at 50 mg/day. A month later, the margins of the erythematous lesions faded, and the infiltration gradually decreased. No recurrence has been observed for one year after the start of the therapy. Anti-oxidative therapy appears to be effective for annular elastolytic giant cell granuloma and could be an alternate therapy for refractory granulomatous disease. 相似文献
Introduction: The current review aimed to outline the functions of the renin angiotensin system (RAS) in the context of the oxidative stress-associated liver disease.
Areas covered: Angiotensin II (Ang II) as the major effector peptide of the RAS is a pro-oxidant and fibrogenic cytokine. Mechanistically, NADPH oxidase (NOX) is a multicomponent enzyme complex that is able to generate reactive oxygen species (ROS) as a downstream signaling pathway of Ang II which is expressed in liver. Ang II has a detrimental role in the pathogenesis of chronic liver disease through possessing pro-oxidant, fibrogenic, and pro-inflammatory impact in the liver. The alternative axis (ACE2/Ang(1-7)/mas) of the RAS serves as an anti-inflammatory, antioxidant and anti-fibrotic component of the RAS.
Expert commentary: In summary, the use of alternative axis inhibitors accompanying with ACE2/ Ang(1-7)/mas axis activation is a promising new strategy serving as a novel therapeutic option to prevent and treat chronic liver diseases. 相似文献
Aster spathulifolius, Coreopsis drummondii, Chrysanthemum morifolium, Chrysanthemum boreale, Chrysanthemum indicum and Rudbeckia laciniata var. hortensis had 30–70 mg gallic acid equivalents (GAE)/g dw of the total phenolic contents. Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing powers of tested Compositae plant extract appeared to be linear and consistent with total phenolic/flavonoids compound contents in the same manner with DPPH radical scavenging activity. R. laciniata (200 µg/mL) inhibited nitric oxide (NO) production to approximately 92.8% from lipopolysaccharide (LPS)-stimulated macrophage cells. Although the total phenolic/flavonoids contents and antioxidant activity of R. laciniata is low compared with other Compositae plants, R. laciniata shows the superior inhibitory activity against NO biosynthesis from LPS-induced macrophage cells. For antiobesity activity, C. boreale, C. morifolium and C. drummondii might act to accelerate lipid degradation and to decrease lipid synthesis in 3T3-L1 adipocyte cells, and C. indicum, A. spathulifolius and R. laciniata extract had antiobesity activity to inhibit lipid synthesis in 3T3-L1 adipocyte cells. 相似文献