- Email: [email protected]
D-penicillamine exerts inhibitory action on hydrogen sulfide biosynthesis
Abstracts/Nitric Oxide 47 (2015) S14–S60
sulfide prevented pulmonary mast cell infiltration and inhibited FGF-2 and IL-13 upregulation. Inhaled hydrogen sulfide was equally effective in a model of airway hyper-reactivity mast cell dependence. The key role for mast cells was further confirmed by the lack of effect of hydrogen sulfide in mast cell deficient mice. Finally, hydrogen sulfide prevented in vitro the degranulation of the mast celllike cell line RBL-2H3. Similarly to the in vivo experiments the inhibitory effect was present only when the cells were activated by antigen exposure. In conclusion inhaled hydrogen sulfide improves lung function and inhibits bronchial hyper-reactivity by modulating mast cells activation.
S39
NaHS (100 μM) for 2 hours. No PDE5 S-sulfhydration could be detected under these conditions either. In conclusion, although H2S inhibits many different PDEs, it exerts selectivity toward PDE5A. PDE1A is rather insensitive to H2S, while cAMP vs cGMP degradation for dual-specificity PDEs is differentially affected by H2S. The mechanism of PDE5A inhibition by H2S occurs in a S-sulfhydration-independent manner. This research has been co-financed by the EU (ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the NSRF – Research Funding Program: Thalis (MIS380259). Investing in Knowledge Society through the European Social Fund.
http://dx.doi.org/10.1016/j.niox.2015.02.094 http://dx.doi.org/10.1016/j.niox.2015.02.095
PP65 Selectivity of hydrogen sulfide toward cyclic nucleotide phosphodiesterases Panagiotis Panopoulos a, Guangdong Yang b, Antonia Asimakopoulou a, Stavros Topouzis a, Rui Wang c, Csaba Szabo d, Andreas Papapetropoulos e a Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Greece b School of Kinesiology, Cardiovascular and Metabolic Research Unit, Lakehead University, Thunder Bay, ON, Canada c Department of Biology, Lakehead University, Thunder Bay, ON, Canada d Department of Anesthesiology, University of Texas Medical Branch, and Shriners Burns Hospital for Children, Galveston TX, USA e Faculty of Pharmacy, University of Athens, Greece Cyclic nucleotide phosphodiesterases (PDEs) are enzymes that regulate the cellular levels of cAMP and cGMP by controlling the rate of their degradation. In mammals, there are 21 different PDEs, derived from 11 genes, that differ in their substrate specificity, mode of regulation and cellular/sub-cellular localization. Hydrogen sulfide (H2S) is an endogenous gasotransmitter and is generated from L-cysteine by two pyridoxal 5′-phosphate-dependent enzymes, cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE), and by the combined action of cysteine aminotransferase (CAT) and 3-mercaptopyruvate sulfurtransferase (3-MST). We have recently shown that H2S increases cellular cGMP by inhibiting PDE activity. In the current study, the selectivity of six phosphodiesterases that have been shown to be expressed in endothelial cells (EC) was tested toward H2S. The recombinant PDEs used were: PDE1A, PDE2A, PDE3B, PDE4A, PDE5A and PDE9A. From these PDE4A is cAMP specific, PDE5A and PDE9A are cGMP specific and PDE1A, PDE2A, PDE3B exhibit dual specificity. Hydrogen sulfide was found to concentration dependently inhibit the activities of all PDEs tested in an in vitro PDE activity assay. Specifically, H2S was significantly more potent in inhibiting cGMP specific PDE5A with an IC50 of 1.6 μM. The IC50 for PDE1A, PDE2A, PDE3B and PDE9A when using cGMP as a substrate was >0.5 mM, 325.9 ± 16.6 μΜ, 61.8 ± 5.4 μΜ and 52.3 ± 2.8 μΜ, respectively. The maximal inhibition observed for PDE1A, PDE2A, PDE3B and PDE9A was 41, 51, 77 and 87%, respectively. The IC50 for PDE1A, PDE2A, PDE3B, PDE4A when using cAMP as a substrate was >1 mΜ, 52.3 ± 5.5 μΜ, 219.9 ± 24.3 μΜ and 65.4 ± 8.4 μM, respectively. The maximal inhibition observed for PDE1A, PDE2A, PDE3B, PDE4A was 28, 82, 55 and 75%, respectively. Since S-sulfhydration has been shown to alter the enzyme activity of multiple proteins, we sought to determine if PDE5 becomes S-sulfhydrated after exposure to NaHS. Mouse aortic smooth muscle cells, as well as human umbilical vein endothelial cells were incubated with 100 μM NaHS for 2 hours; H2S had no effect on PDE5 S-sulfhydration in either cell type. Furthermore, HEK-293 cells were transfected with PDE5 cDNA; 48 hours later, cells were treated with
PP66 D-penicillamine exerts inhibitory action on hydrogen sulfide biosynthesis Vincenzo Brancaleone a, Valentina Vellecco b, Iolanda Esposito b, Antonella Gargiulo b, Antonio Bertolino b, Antonia Asimakopoulou c, Andreas Papapetropoulos c, Mariarosaria Bucci b, Giuseppe Cirino b a Department of Science, University of Basilicata, Italy b Department of Pharmacy, University of Naples Federico II, Italy c Department of Pharmaceutical Chemistry, University of Athens, Greece Hydrogen sulfide (H2S) is a gasotransmitter mainly released from L-cysteine following cystathionine-gamma-lyase (CSE) and/or cystathionine-beta-synthase (CBS) enzymatic action [1,2]. The pathway leading to H2S release has been extensively investigated and, with respect to the vascular system, CSE seems to represent the prominent enzyme, since it shows deep implications in regulating blood vessels and heart function [3,4]. Noteworthy, the majority of work in the field of H2S research, including vascular, gastrointestinal, inflammation and neuronal studies, have been achieved by using ’inhibitors’ that may not entirely reflect specificity or selectivity for CSE and/or CBS [5]. This aspect highlights the important requirement of discovering new pharmacological tools able to better meet the need for selective and/or specific molecules. For such a reason, the aim of this work was to investigate the possible effect on vascular H2S biosynthesis operated by D-penicillamin (D-pen), an old molecule used in therapy in the ’70s [6] and with a very similar structure to L-cysteine. We first observed that D-pen was not able to induce any substantial vasorelaxation in phenylephrine pre-contracted mouse aorta (<20%), compared to L-cysteine. Interestingly, vasodilation induced by L-cysteine was significantly blocked when the aorta was pre-treated with D-pen and the inhibition observed was concentration-dependent (10–1000 μM). Such an effect was also observed when Ach and isoprenaline were used as a vasodilating agent, though the inhibition was consistently less pronounced. We also tested whether D-pen was able to block H2S biosynthesis in aorta homogenated samples and the data obtained showed that D-pen significantly inhibited H2S production in a concentrationdependent manner (10–1000 μM). Notably, the blocking effect exerted by D-pen was associated with selective CSE inhibition and rescued by the addition of 5′-pyridoxal-phosphate. In conclusion, our results suggest that D-pen is a selective CSE inhibitor and it could be potentially used as a specific pharmacological tool in the H2S research field. Furthermore, these data may have important implications about an obsolete molecule used in therapy, since some of the therapeutic properties shown by D-pen have never been univocally identified. Therefore, the involvement
S40
Abstracts/Nitric Oxide 47 (2015) S14–S60
of H2S biosynthesis in the D-pen mechanism of action could open new perspectives in therapeutic approach.
PP68 Exogenous hydrogen sulfide alleviates impairment of central chemoreception induced by prenatal cigarette smoke exposure in neonatal rats
References [1] [2] [3] [4] [5] [6]
C. Szabo, Nat. Rev. Drug Discov. 6 (11) (2007) 917–935. L. Li, et al., Annu. Rev. Pharmacol. Toxicol. 51 (2011) 169–187. G. Yang, et al., Science 322 (5901) (2008) 587–590. M. Lavu, et al., Clin. Sci. (Lond.) 120 (6) (2011) 219–229. M. Whiteman, et al., Clin. Sci. (Lond.) 121 (11) (2011) 459–488. J.R. Golding, et al., Postgrad. Med. J. 46 (540) (2007) 599–605.
http://dx.doi.org/10.1016/j.niox.2015.02.096
PP67 Effects of mitochondria-targeted and non-targeted hydrogen sulphide donors on platelet aggregation Barbara Sitek a, Matthew Whiteman b, Stefan Chłopicki a a Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzyn ´ skiego 14, Kraków, Poland b University of Exeter, UK Platelet activation is a major cause of intravascular thrombosis that occurs when endothelial anti-platelet mechanisms are impaired. The major anti-platelet mechanisms afforded by the endothelium are linked to endothelial PGI2, NO, CO, and ADP-ase activity and possibly also to H2S generation. H2S shares many biological effects with NO and CO, including inhibition of platelet aggregation. Anti-platelet properties of H2S may involve different mechanisms, like: S-sulphhydration of blood platelets proteins, the decrease of calcium level in platelets, the decrease of superoxide anion (which acts like a second messenger) or upregulation of NO synthesis. The aim of the present work was to compare the effect of mitochondria-targeted and non-targeted compounds on platelet aggregation. Methods: Venous blood was obtained from human volunteers at the University Hospital Blood Bank Centre. Aggregation of blood platelets in PRP (platelet rich plasma) was assessed using Chronolog aggregometer (Chrono-log Corp., USA) by measurements of optic transmittance according to the classic method described by Born. Results: We analysed the anti-platelet activity of various classic H2S-donors, such as: GYY, AP 106, AP 105 and AP 72. All tested classic H2S-donors inhibited platelet aggregation in millimolar concentration (300 μM–3 mM). AP 106 was significantly weaker as compared to others. GYY was weaker than Na+ (GYY salt). AP 72 did not affect platelet aggregation even at mM concentration. In turn AP 39 and AP 123 (mitochondria-targeted compounds) inhibited platelet aggregation in a micromolar range of concentrations (30–100 μM). Conclusions: H2S-donors targeted to mitochondria may constitute an attractive and novel approach to inhibit platelet aggregation.
S O Br-
Ph3P
n
O
http://dx.doi.org/10.1016/j.niox.2015.02.097
S S
Fang Lei, Xiang Yan, Fusheng Zhao, Senfeng Zhang, Qilan Zhang, Hua Zhou, Yu Zheng Department of Physiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China It has been elucidated that prenatal cigarette smoke exposure (CS) may lead to damage to the central nervous system and might be related to such diseases as sudden infant death syndrome, and that hydrogen sulfide (H2S) plays important roles in protecting the neurons against injuries induced by a variety of factors. The purpose of the present study was to investigate whether prenatal CS could give rise to suppression of the central chemoreception in neonatal rats, and whether H2S could attenuate the impairment of the chemoreception. The rat CS model was established. NaHS (a donor of H2S) or saline was intraperitoneally injected into pregnant rats half an hour before the CS during gestation days 7–20. Medullary slice preparations, containing the pre-Bötzinger complex and the parafacial respiratory group, were obtained using a vibratome from neonatal (postnatal 2 days) rats. The electrical activity of hypoglossal rootlets of the slice was recorded to observe the change in its burst frequency (BF) resulting from acidized artificial cerebrospinal fluid (aCSF, pH = 7.0). In the control (saline injection) preparations, acidification of aCSF increased BF of the hypoglossal rootlets (p < 0.05). In the CS preparations, the increase in BF induced by acidification was reduced compared with the control preparations (p < 0.05). In the CS plus NaHS treatment preparations, the CSinduced suppression of increase in BF was significantly ameliorated (p < 0.05), although the change in BF was still lower than that in the control preparations (p < 0.05). There was no remarkable difference in the change in BF between the control and NaHS preparations (p > 0.05). The results indicate that prenatal CS can lead to suppression of the central chemoreception in neonatal rats, and H2S can dramatically ameliorate CS-induced impairment of the chemoreception, suggesting that administration of exogenous H2S might provide a therapeutic approach for central chemoreception deficit. Keywords: Hydrogen sulfide; central chemoreception; prenatal cigarette smoke exposure; neonatal rat http://dx.doi.org/10.1016/j.niox.2015.02.098
PP69 Hydrogen sulfide as an endogenous “controller” of human melanoma progression Elisabetta Panza a, Paola De Cicco a, Chiara Armogida a, Giuseppe Ercolano a, Vincenzo Gigantino b, Gerardo Botti b, Maria Napolitano c, Andreas Papapetropoulos d, Valentina Mattera Iacono a, Mariarosaria Bucci a, Giuseppe Cirino a, Angela Ianaro a a Department of Pharmacy, University of Naples Federico II, Naples, Italy b Unit of Pathology, Istituto Nazionale per lo Studio e la cura dei tumori “Fondazione G. Pascale” IRCCS, Naples, Italy c Department of Oncological Immunology, Istituto Nazionale per lo Studio e la cura dei tumori "Fondazione Giovanni Pascale" IRCCS, Naples, Italy d Department of Pharmacy, University of Athens, Athens, Greece Metastatic melanoma is an aggressive disease with a median survival of less than 1 year. Although dramatic improvements have been made in the last two years with the approval of several new drugs for the treatment of metastatic melanoma, most responses of these
sulfide prevented pulmonary mast cell infiltration and inhibited FGF-2 and IL-13 upregulation. Inhaled hydrogen sulfide was equally effective in a model of airway hyper-reactivity mast cell dependence. The key role for mast cells was further confirmed by the lack of effect of hydrogen sulfide in mast cell deficient mice. Finally, hydrogen sulfide prevented in vitro the degranulation of the mast celllike cell line RBL-2H3. Similarly to the in vivo experiments the inhibitory effect was present only when the cells were activated by antigen exposure. In conclusion inhaled hydrogen sulfide improves lung function and inhibits bronchial hyper-reactivity by modulating mast cells activation.
S39
NaHS (100 μM) for 2 hours. No PDE5 S-sulfhydration could be detected under these conditions either. In conclusion, although H2S inhibits many different PDEs, it exerts selectivity toward PDE5A. PDE1A is rather insensitive to H2S, while cAMP vs cGMP degradation for dual-specificity PDEs is differentially affected by H2S. The mechanism of PDE5A inhibition by H2S occurs in a S-sulfhydration-independent manner. This research has been co-financed by the EU (ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the NSRF – Research Funding Program: Thalis (MIS380259). Investing in Knowledge Society through the European Social Fund.
http://dx.doi.org/10.1016/j.niox.2015.02.094 http://dx.doi.org/10.1016/j.niox.2015.02.095
PP65 Selectivity of hydrogen sulfide toward cyclic nucleotide phosphodiesterases Panagiotis Panopoulos a, Guangdong Yang b, Antonia Asimakopoulou a, Stavros Topouzis a, Rui Wang c, Csaba Szabo d, Andreas Papapetropoulos e a Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, Greece b School of Kinesiology, Cardiovascular and Metabolic Research Unit, Lakehead University, Thunder Bay, ON, Canada c Department of Biology, Lakehead University, Thunder Bay, ON, Canada d Department of Anesthesiology, University of Texas Medical Branch, and Shriners Burns Hospital for Children, Galveston TX, USA e Faculty of Pharmacy, University of Athens, Greece Cyclic nucleotide phosphodiesterases (PDEs) are enzymes that regulate the cellular levels of cAMP and cGMP by controlling the rate of their degradation. In mammals, there are 21 different PDEs, derived from 11 genes, that differ in their substrate specificity, mode of regulation and cellular/sub-cellular localization. Hydrogen sulfide (H2S) is an endogenous gasotransmitter and is generated from L-cysteine by two pyridoxal 5′-phosphate-dependent enzymes, cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE), and by the combined action of cysteine aminotransferase (CAT) and 3-mercaptopyruvate sulfurtransferase (3-MST). We have recently shown that H2S increases cellular cGMP by inhibiting PDE activity. In the current study, the selectivity of six phosphodiesterases that have been shown to be expressed in endothelial cells (EC) was tested toward H2S. The recombinant PDEs used were: PDE1A, PDE2A, PDE3B, PDE4A, PDE5A and PDE9A. From these PDE4A is cAMP specific, PDE5A and PDE9A are cGMP specific and PDE1A, PDE2A, PDE3B exhibit dual specificity. Hydrogen sulfide was found to concentration dependently inhibit the activities of all PDEs tested in an in vitro PDE activity assay. Specifically, H2S was significantly more potent in inhibiting cGMP specific PDE5A with an IC50 of 1.6 μM. The IC50 for PDE1A, PDE2A, PDE3B and PDE9A when using cGMP as a substrate was >0.5 mM, 325.9 ± 16.6 μΜ, 61.8 ± 5.4 μΜ and 52.3 ± 2.8 μΜ, respectively. The maximal inhibition observed for PDE1A, PDE2A, PDE3B and PDE9A was 41, 51, 77 and 87%, respectively. The IC50 for PDE1A, PDE2A, PDE3B, PDE4A when using cAMP as a substrate was >1 mΜ, 52.3 ± 5.5 μΜ, 219.9 ± 24.3 μΜ and 65.4 ± 8.4 μM, respectively. The maximal inhibition observed for PDE1A, PDE2A, PDE3B, PDE4A was 28, 82, 55 and 75%, respectively. Since S-sulfhydration has been shown to alter the enzyme activity of multiple proteins, we sought to determine if PDE5 becomes S-sulfhydrated after exposure to NaHS. Mouse aortic smooth muscle cells, as well as human umbilical vein endothelial cells were incubated with 100 μM NaHS for 2 hours; H2S had no effect on PDE5 S-sulfhydration in either cell type. Furthermore, HEK-293 cells were transfected with PDE5 cDNA; 48 hours later, cells were treated with
PP66 D-penicillamine exerts inhibitory action on hydrogen sulfide biosynthesis Vincenzo Brancaleone a, Valentina Vellecco b, Iolanda Esposito b, Antonella Gargiulo b, Antonio Bertolino b, Antonia Asimakopoulou c, Andreas Papapetropoulos c, Mariarosaria Bucci b, Giuseppe Cirino b a Department of Science, University of Basilicata, Italy b Department of Pharmacy, University of Naples Federico II, Italy c Department of Pharmaceutical Chemistry, University of Athens, Greece Hydrogen sulfide (H2S) is a gasotransmitter mainly released from L-cysteine following cystathionine-gamma-lyase (CSE) and/or cystathionine-beta-synthase (CBS) enzymatic action [1,2]. The pathway leading to H2S release has been extensively investigated and, with respect to the vascular system, CSE seems to represent the prominent enzyme, since it shows deep implications in regulating blood vessels and heart function [3,4]. Noteworthy, the majority of work in the field of H2S research, including vascular, gastrointestinal, inflammation and neuronal studies, have been achieved by using ’inhibitors’ that may not entirely reflect specificity or selectivity for CSE and/or CBS [5]. This aspect highlights the important requirement of discovering new pharmacological tools able to better meet the need for selective and/or specific molecules. For such a reason, the aim of this work was to investigate the possible effect on vascular H2S biosynthesis operated by D-penicillamin (D-pen), an old molecule used in therapy in the ’70s [6] and with a very similar structure to L-cysteine. We first observed that D-pen was not able to induce any substantial vasorelaxation in phenylephrine pre-contracted mouse aorta (<20%), compared to L-cysteine. Interestingly, vasodilation induced by L-cysteine was significantly blocked when the aorta was pre-treated with D-pen and the inhibition observed was concentration-dependent (10–1000 μM). Such an effect was also observed when Ach and isoprenaline were used as a vasodilating agent, though the inhibition was consistently less pronounced. We also tested whether D-pen was able to block H2S biosynthesis in aorta homogenated samples and the data obtained showed that D-pen significantly inhibited H2S production in a concentrationdependent manner (10–1000 μM). Notably, the blocking effect exerted by D-pen was associated with selective CSE inhibition and rescued by the addition of 5′-pyridoxal-phosphate. In conclusion, our results suggest that D-pen is a selective CSE inhibitor and it could be potentially used as a specific pharmacological tool in the H2S research field. Furthermore, these data may have important implications about an obsolete molecule used in therapy, since some of the therapeutic properties shown by D-pen have never been univocally identified. Therefore, the involvement
S40
Abstracts/Nitric Oxide 47 (2015) S14–S60
of H2S biosynthesis in the D-pen mechanism of action could open new perspectives in therapeutic approach.
PP68 Exogenous hydrogen sulfide alleviates impairment of central chemoreception induced by prenatal cigarette smoke exposure in neonatal rats
References [1] [2] [3] [4] [5] [6]
C. Szabo, Nat. Rev. Drug Discov. 6 (11) (2007) 917–935. L. Li, et al., Annu. Rev. Pharmacol. Toxicol. 51 (2011) 169–187. G. Yang, et al., Science 322 (5901) (2008) 587–590. M. Lavu, et al., Clin. Sci. (Lond.) 120 (6) (2011) 219–229. M. Whiteman, et al., Clin. Sci. (Lond.) 121 (11) (2011) 459–488. J.R. Golding, et al., Postgrad. Med. J. 46 (540) (2007) 599–605.
http://dx.doi.org/10.1016/j.niox.2015.02.096
PP67 Effects of mitochondria-targeted and non-targeted hydrogen sulphide donors on platelet aggregation Barbara Sitek a, Matthew Whiteman b, Stefan Chłopicki a a Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzyn ´ skiego 14, Kraków, Poland b University of Exeter, UK Platelet activation is a major cause of intravascular thrombosis that occurs when endothelial anti-platelet mechanisms are impaired. The major anti-platelet mechanisms afforded by the endothelium are linked to endothelial PGI2, NO, CO, and ADP-ase activity and possibly also to H2S generation. H2S shares many biological effects with NO and CO, including inhibition of platelet aggregation. Anti-platelet properties of H2S may involve different mechanisms, like: S-sulphhydration of blood platelets proteins, the decrease of calcium level in platelets, the decrease of superoxide anion (which acts like a second messenger) or upregulation of NO synthesis. The aim of the present work was to compare the effect of mitochondria-targeted and non-targeted compounds on platelet aggregation. Methods: Venous blood was obtained from human volunteers at the University Hospital Blood Bank Centre. Aggregation of blood platelets in PRP (platelet rich plasma) was assessed using Chronolog aggregometer (Chrono-log Corp., USA) by measurements of optic transmittance according to the classic method described by Born. Results: We analysed the anti-platelet activity of various classic H2S-donors, such as: GYY, AP 106, AP 105 and AP 72. All tested classic H2S-donors inhibited platelet aggregation in millimolar concentration (300 μM–3 mM). AP 106 was significantly weaker as compared to others. GYY was weaker than Na+ (GYY salt). AP 72 did not affect platelet aggregation even at mM concentration. In turn AP 39 and AP 123 (mitochondria-targeted compounds) inhibited platelet aggregation in a micromolar range of concentrations (30–100 μM). Conclusions: H2S-donors targeted to mitochondria may constitute an attractive and novel approach to inhibit platelet aggregation.
S O Br-
Ph3P
n
O
http://dx.doi.org/10.1016/j.niox.2015.02.097
S S
Fang Lei, Xiang Yan, Fusheng Zhao, Senfeng Zhang, Qilan Zhang, Hua Zhou, Yu Zheng Department of Physiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China It has been elucidated that prenatal cigarette smoke exposure (CS) may lead to damage to the central nervous system and might be related to such diseases as sudden infant death syndrome, and that hydrogen sulfide (H2S) plays important roles in protecting the neurons against injuries induced by a variety of factors. The purpose of the present study was to investigate whether prenatal CS could give rise to suppression of the central chemoreception in neonatal rats, and whether H2S could attenuate the impairment of the chemoreception. The rat CS model was established. NaHS (a donor of H2S) or saline was intraperitoneally injected into pregnant rats half an hour before the CS during gestation days 7–20. Medullary slice preparations, containing the pre-Bötzinger complex and the parafacial respiratory group, were obtained using a vibratome from neonatal (postnatal 2 days) rats. The electrical activity of hypoglossal rootlets of the slice was recorded to observe the change in its burst frequency (BF) resulting from acidized artificial cerebrospinal fluid (aCSF, pH = 7.0). In the control (saline injection) preparations, acidification of aCSF increased BF of the hypoglossal rootlets (p < 0.05). In the CS preparations, the increase in BF induced by acidification was reduced compared with the control preparations (p < 0.05). In the CS plus NaHS treatment preparations, the CSinduced suppression of increase in BF was significantly ameliorated (p < 0.05), although the change in BF was still lower than that in the control preparations (p < 0.05). There was no remarkable difference in the change in BF between the control and NaHS preparations (p > 0.05). The results indicate that prenatal CS can lead to suppression of the central chemoreception in neonatal rats, and H2S can dramatically ameliorate CS-induced impairment of the chemoreception, suggesting that administration of exogenous H2S might provide a therapeutic approach for central chemoreception deficit. Keywords: Hydrogen sulfide; central chemoreception; prenatal cigarette smoke exposure; neonatal rat http://dx.doi.org/10.1016/j.niox.2015.02.098
PP69 Hydrogen sulfide as an endogenous “controller” of human melanoma progression Elisabetta Panza a, Paola De Cicco a, Chiara Armogida a, Giuseppe Ercolano a, Vincenzo Gigantino b, Gerardo Botti b, Maria Napolitano c, Andreas Papapetropoulos d, Valentina Mattera Iacono a, Mariarosaria Bucci a, Giuseppe Cirino a, Angela Ianaro a a Department of Pharmacy, University of Naples Federico II, Naples, Italy b Unit of Pathology, Istituto Nazionale per lo Studio e la cura dei tumori “Fondazione G. Pascale” IRCCS, Naples, Italy c Department of Oncological Immunology, Istituto Nazionale per lo Studio e la cura dei tumori "Fondazione Giovanni Pascale" IRCCS, Naples, Italy d Department of Pharmacy, University of Athens, Athens, Greece Metastatic melanoma is an aggressive disease with a median survival of less than 1 year. Although dramatic improvements have been made in the last two years with the approval of several new drugs for the treatment of metastatic melanoma, most responses of these