Effect of Hydrogen Sulfide on Cyclic AMP Production in Isolated Bovine and Porcine Neural Retinae
- 168 Downloads
Hydrogen sulfide (H2S) has been reported to exert pharmacological effects on neural and non-neural tissues from several mammalian species. In the present study, we examined the role of the intracellular messenger, cyclic AMP in retinal response to H2S donors, sodium hydrosulfide (NaHS) and sodium sulfide (Na2S) in cows and pigs. Isolated bovine and porcine neural retinae were incubated in oxygenated Krebs buffer solution prior to exposure to varying concentrations of NaHS, Na2S or the diterpene activator of adenylate cyclase, forskolin. After incubation at different time intervals, tissue homogenates were prepared for cyclic AMP assay using a well established methodology. In isolated bovine and porcine retinae, the combination of both phosphodiesterase inhibitor, IBMX (2 mM) and forskolin (10 μM) produced a synergistic increase (P < 0.001) in cyclic AMP concentrations over basal levels. NaHS (10 nM–100 μM) produced a time-dependent increase in cyclic AMP concentrations over basal levels which reached a maximum at 20 min in both bovine and porcine retinae. At this time point, both NaHS and Na2S (10 nM–100 μM) caused a significant (P < 0.05) dose-dependent increase in cyclic AMP levels in bovine and porcine retinae. For instance, NaHS (100 nM) elicited a four-fold and three-fold increase in cyclic AMP concentrations in bovine and porcine retinae respectively whilst higher concentrations of Na2S (100 μM) produced a much lesser effect in both species. In bovine and porcine retinae, the effects caused by forskolin (10 μM) on cyclic AMP production were not potentiated by addition of low or high concentrations of both NaHS and Na2S. We conclude that H2S donors can increase cyclic AMP production in isolated neural retinae from cows and pigs. Bovine retina appears to be more sensitive to the stimulatory effect of H2S donors on cyclic nucleotide production than its porcine counterpart indicating that species differences exist in the magnitude of this response. Furthermore, effects produced by forskolin on cyclic AMP formation were not additive with those elicited by H2S donors suggesting that these agents may share a common mechanism in their action on the adenylyl cyclase pathway.
KeywordsHydrogen sulfide Cyclic AMP Retina Sodium sulfide Sodium hydrosulfide
- Cyclic AMP
Adenosine 3′,5′ cyclic monophosphate
We acknowledge the excellent secretarial assistance of Ms. Carolyn Wahl of the University of Houston, College of Pharmacy in preparing this manuscript.
- 10.Kraft AA, Brant AW, Ayres JC (1956) Detection of hydrogen sulphide in packaged meals and in broken-out shell eggs. Food Technol 10:443–444Google Scholar
- 16.Kraus JP, Kozich V (2001) Cystathionine β-synthase and its deficiency. In: Carmel R, Jacobsen DW (eds) Homocysteine in health and disease. Cambridge University Press, Cambridge, pp 223–243Google Scholar
- 17.Mudd SH, Levy HL, Kraus JP (2001) Disorders of trans-sulfuration. In: Scriver CR, Beaudet AL, Sly WS, Valle D, Childs B, Kinzler K, Vogelstein B (eds) The metabolic and molecular bases of inherited disease. McGraw-Hill, New York, pp 2007–2056Google Scholar
- 26.Njie Y, Bongmba OYN, Opere CA et al (2008) Regulation of mammalian retinal neurotransmitter function by hydrogen sulfide: role of cyclic AMP. Invest Ophthalmol Vis Sci E-Abstract 2005Google Scholar