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P5 Protective effects of hydrogen sulfide in the development of atherosclerosis in hyperlipidemic rabbit
Abstracts / Nitric Oxide 27 (2012) S11–S42
challenge were associated with upregulation of gene expression of anti-inflammatory IL-10, which stimulates STAT3 phosphorylation, in the liver. These results suggest that inhaled H2S contributes to survival of mice in acute liver failure at least in part through activation of IL-10/STAT3 pathway. Conclusion: These results suggest that H2S protects mice from acute liver failure at least in part by inhibition of caspase activation and by augmentation of IL-10/STAT3 signaling pathway in the liver. Disclosure: Nothing to disclose http://dx.doi.org/10.1016/j.niox.2012.08.004
P4 Antiinflammatory and antinociceptive effects of ATB-346, a gastric sparing hydrogen sulfide-releasing naproxen, in rats with carrageenan-induced knee joint synovitis Eduardo Ekundi-Valentim a,b, Leandro Rodrigues a, Karen Santos a, Simone Teixeira a, John Wallace c, Soraia Costa a, Marcelo Muscará a a Institute of Biomedical Sciences, University of Sao Paulo (Brazil), Pharmacology, Sao Paolo, Sao Paolo 05586040, Brazil b Institute of Health Sciences, University Agostinho Neto (Angola), Pharmacology, Luanda, Luanda 03578, Angola c Farncombe Institute, McMaster University (Canada), Ontario, Hamilton, Canada L8S 4K1 Background: Non-steroidal antiinflammatory drugs (NSAIDs) are the most commonly prescribed agents in arthritic patients, although the gastric effects limit their long-term use. Considering the gastric safeness of H2S-releasing NSAIDs (FASEB J 2006; 20: 2118), in addition to the beneficial effects of H2S in rat synovitis (Br J Pharmacol 2010; 159: 1463), we evaluated NAP and ATB-346 in rats with CGN-induced sinovitis. Methods: Anesthetized (5% halothane in O2) male Wistar rats were pre-treated with either NAP (0.3, 1, 3 or 10 mg/kg) or equimolar ATB-346 doses (0.48, 1.6, 4.8, or 16 mg/kg) 30 min before the i.art. injection of 7.5 mg of CGN. Joint swelling and pain score were assessed 1, 3 and 5 h after CGN, and tactile allodynia (von Frey filaments) after 2 and 4 h. At the end, joint cavity lavages were collected for leukocyte counting. The drugs (at the highest doses) were also tested for their gastric effects by evaluating mucosa integrity (macroscopical) and neutrophil recruitment (as myeloperoxidase – MPO activity). Results: CGN induced edema, pain, tactile allodynia and leukocyte infiltration into the joint cavity. Edema and pain score (at 3 and 5 h after CGN) were reduced by both NAP and ATB-346 at the two highest doses (p < 0.001). Tactile allodynia (4 h after CGN) was also similarly inhibited (by 45%; p < 0.001) by both NAP (at 1, 3 and 10 mg/ kg) and ATB346 (at 1.6 and 4.8 mg/kg), as well as leukocyte infiltration. No macroscopical lesions of the gastric mucosa were observed in any of the groups; however, NAP (but not ABT-346) increased gastric MPO (130%). Conclusion: We conclude that the H2S-releasing moiety in the ATB-346 structure protects the gastric mucosa from the parent drug-induced side-effects and does not reduce NAP efficacy for the control of local inflammation and hyperalgesia in rats with CGNinduced synovitis. Financial support: FAPESP, CNPq, CAPES, Agostino Neto and McMaster University. Disclosure: No response indicated. http://dx.doi.org/10.1016/j.niox.2012.08.005
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P5 Protective effects of hydrogen sulfide in the development of atherosclerosis in hyperlipidemic rabbit Ya-Dan Wen a, Hong Wang a, Yi-Zhun Zhu a,b a National University of Singapore, Pharmacology, Singapore 117597, Singapore b Fudan Univeristy, School of Pharmacy, Shanghai 201203, China Background: Several studies have showed the protective effects of Hydrogen sulfide (H2S) in hypertension, ischemia/reperfusion and Alzheimer’s disease, but its effects and mechanisms on atherosclerosis are still unknown. This study aims to examine the protection of H2S in a hyperlipidemic rabbit model of atherosclerosis. Methods: Thirty-six male New Zealand White rabbits (6 groups, n = 6) were fed a normal diet or a high-cholesterol diet (1%). Rabbits fed on high-cholesterol diet received treatments of saline, NaHS (1, 10, 30 lmol/kg/d) or PAG. After 8 weeks, animals underwent ultrasonographic imaging then sacrificed for further pathological and molecular biological analysis. Results: We found that H2S attenuated atherosclerotic lesions though regulating redox status by interrupting oxidative modification of LDL and enhancing antioxidative abilities in vascular environment. The examination of plasma H2S levels, aortic CSE activities, and protein and gene expressions of CSE indicated the involvement of CSE/ H2S pathway during atherosclerosis. The morphologic changes, observed by H & E, showed that the increased initma-media thickness and atherosclerotic plaques stimulated by high cholesterol diet can be reversed by exposure of H2S or exacerbated by CSE inhibitor, PAG. High resolution ultrasonography performed at carotids also supported H & E results. TEM showed ultrastructures of aorta in hyperlipidemic rabbits, presenting messy collagens, lipid droplets and vacuoles in thicken subendothelium and swollen mitochondria, condensate chromatin and expanding endoplasmic reticulum with cell debris and lipid droplets in smooth muscle cells, which were rarely observed in treatments of H2S. Next, the lipid profile in plasma showed that the increased levels of ox-LDL in hyperlipidemic rabbits were decreased by expose of H2S. Moreover, the regulation of modification of LDL by H2S also represented that the highly induced malonaldehyde (MDA) was inhibited by H2S and exposure of H2S elevated the expression of cardioprotective enzyme, heme oxygenase-1 (HO-1). Finally, the activities and protein expressions of antioxidants enzymes (SOD, CAT, GST, GPx) and GSH were retained by H2S showing its antioxidative effects. Propargylglycine (PAG), a selective inhibitor of CSE, abolished the protective effects of H2S used in the current model. Conclusion: In this rabbit atherosclerosis model, H2S implemented cardioprotection from moderating the oxidative modification of LDL, attenuating the progression of atherosclerotic lesion and ameliorating oxidative stress, which are though CSE/H2S pathway. This study analyzed for the first time that, regulatory effects of H2S on redox status though influencing modification of LDL and antioxidative abilities in in vivo study. These findings suggest that H2S might be a potential agent for treatment of atherosclerosis. Disclosure: No response indicated. http://dx.doi.org/10.1016/j.niox.2012.08.006
P6 Hydrogen sulfide activates Ca2+ sparks to induce cerebral arteriole dilation Guohua Liang, Qi xi, Charles Leffler, Jonathan Jaggar University of Tennessee Health Science Center, Department of Physiology, Memphis, TN 38163, United States Hydrogen sulfide (H2S) is a gaseous vasodilator produced by endothelial cells. Mechanisms by which H2S induce vasodilation
challenge were associated with upregulation of gene expression of anti-inflammatory IL-10, which stimulates STAT3 phosphorylation, in the liver. These results suggest that inhaled H2S contributes to survival of mice in acute liver failure at least in part through activation of IL-10/STAT3 pathway. Conclusion: These results suggest that H2S protects mice from acute liver failure at least in part by inhibition of caspase activation and by augmentation of IL-10/STAT3 signaling pathway in the liver. Disclosure: Nothing to disclose http://dx.doi.org/10.1016/j.niox.2012.08.004
P4 Antiinflammatory and antinociceptive effects of ATB-346, a gastric sparing hydrogen sulfide-releasing naproxen, in rats with carrageenan-induced knee joint synovitis Eduardo Ekundi-Valentim a,b, Leandro Rodrigues a, Karen Santos a, Simone Teixeira a, John Wallace c, Soraia Costa a, Marcelo Muscará a a Institute of Biomedical Sciences, University of Sao Paulo (Brazil), Pharmacology, Sao Paolo, Sao Paolo 05586040, Brazil b Institute of Health Sciences, University Agostinho Neto (Angola), Pharmacology, Luanda, Luanda 03578, Angola c Farncombe Institute, McMaster University (Canada), Ontario, Hamilton, Canada L8S 4K1 Background: Non-steroidal antiinflammatory drugs (NSAIDs) are the most commonly prescribed agents in arthritic patients, although the gastric effects limit their long-term use. Considering the gastric safeness of H2S-releasing NSAIDs (FASEB J 2006; 20: 2118), in addition to the beneficial effects of H2S in rat synovitis (Br J Pharmacol 2010; 159: 1463), we evaluated NAP and ATB-346 in rats with CGN-induced sinovitis. Methods: Anesthetized (5% halothane in O2) male Wistar rats were pre-treated with either NAP (0.3, 1, 3 or 10 mg/kg) or equimolar ATB-346 doses (0.48, 1.6, 4.8, or 16 mg/kg) 30 min before the i.art. injection of 7.5 mg of CGN. Joint swelling and pain score were assessed 1, 3 and 5 h after CGN, and tactile allodynia (von Frey filaments) after 2 and 4 h. At the end, joint cavity lavages were collected for leukocyte counting. The drugs (at the highest doses) were also tested for their gastric effects by evaluating mucosa integrity (macroscopical) and neutrophil recruitment (as myeloperoxidase – MPO activity). Results: CGN induced edema, pain, tactile allodynia and leukocyte infiltration into the joint cavity. Edema and pain score (at 3 and 5 h after CGN) were reduced by both NAP and ATB-346 at the two highest doses (p < 0.001). Tactile allodynia (4 h after CGN) was also similarly inhibited (by 45%; p < 0.001) by both NAP (at 1, 3 and 10 mg/ kg) and ATB346 (at 1.6 and 4.8 mg/kg), as well as leukocyte infiltration. No macroscopical lesions of the gastric mucosa were observed in any of the groups; however, NAP (but not ABT-346) increased gastric MPO (130%). Conclusion: We conclude that the H2S-releasing moiety in the ATB-346 structure protects the gastric mucosa from the parent drug-induced side-effects and does not reduce NAP efficacy for the control of local inflammation and hyperalgesia in rats with CGNinduced synovitis. Financial support: FAPESP, CNPq, CAPES, Agostino Neto and McMaster University. Disclosure: No response indicated. http://dx.doi.org/10.1016/j.niox.2012.08.005
S13
P5 Protective effects of hydrogen sulfide in the development of atherosclerosis in hyperlipidemic rabbit Ya-Dan Wen a, Hong Wang a, Yi-Zhun Zhu a,b a National University of Singapore, Pharmacology, Singapore 117597, Singapore b Fudan Univeristy, School of Pharmacy, Shanghai 201203, China Background: Several studies have showed the protective effects of Hydrogen sulfide (H2S) in hypertension, ischemia/reperfusion and Alzheimer’s disease, but its effects and mechanisms on atherosclerosis are still unknown. This study aims to examine the protection of H2S in a hyperlipidemic rabbit model of atherosclerosis. Methods: Thirty-six male New Zealand White rabbits (6 groups, n = 6) were fed a normal diet or a high-cholesterol diet (1%). Rabbits fed on high-cholesterol diet received treatments of saline, NaHS (1, 10, 30 lmol/kg/d) or PAG. After 8 weeks, animals underwent ultrasonographic imaging then sacrificed for further pathological and molecular biological analysis. Results: We found that H2S attenuated atherosclerotic lesions though regulating redox status by interrupting oxidative modification of LDL and enhancing antioxidative abilities in vascular environment. The examination of plasma H2S levels, aortic CSE activities, and protein and gene expressions of CSE indicated the involvement of CSE/ H2S pathway during atherosclerosis. The morphologic changes, observed by H & E, showed that the increased initma-media thickness and atherosclerotic plaques stimulated by high cholesterol diet can be reversed by exposure of H2S or exacerbated by CSE inhibitor, PAG. High resolution ultrasonography performed at carotids also supported H & E results. TEM showed ultrastructures of aorta in hyperlipidemic rabbits, presenting messy collagens, lipid droplets and vacuoles in thicken subendothelium and swollen mitochondria, condensate chromatin and expanding endoplasmic reticulum with cell debris and lipid droplets in smooth muscle cells, which were rarely observed in treatments of H2S. Next, the lipid profile in plasma showed that the increased levels of ox-LDL in hyperlipidemic rabbits were decreased by expose of H2S. Moreover, the regulation of modification of LDL by H2S also represented that the highly induced malonaldehyde (MDA) was inhibited by H2S and exposure of H2S elevated the expression of cardioprotective enzyme, heme oxygenase-1 (HO-1). Finally, the activities and protein expressions of antioxidants enzymes (SOD, CAT, GST, GPx) and GSH were retained by H2S showing its antioxidative effects. Propargylglycine (PAG), a selective inhibitor of CSE, abolished the protective effects of H2S used in the current model. Conclusion: In this rabbit atherosclerosis model, H2S implemented cardioprotection from moderating the oxidative modification of LDL, attenuating the progression of atherosclerotic lesion and ameliorating oxidative stress, which are though CSE/H2S pathway. This study analyzed for the first time that, regulatory effects of H2S on redox status though influencing modification of LDL and antioxidative abilities in in vivo study. These findings suggest that H2S might be a potential agent for treatment of atherosclerosis. Disclosure: No response indicated. http://dx.doi.org/10.1016/j.niox.2012.08.006
P6 Hydrogen sulfide activates Ca2+ sparks to induce cerebral arteriole dilation Guohua Liang, Qi xi, Charles Leffler, Jonathan Jaggar University of Tennessee Health Science Center, Department of Physiology, Memphis, TN 38163, United States Hydrogen sulfide (H2S) is a gaseous vasodilator produced by endothelial cells. Mechanisms by which H2S induce vasodilation