Retinal on-bipolar cells contain a nitric oxide-sensitive guanylate cyclase.
Retinal on-bipolar cells possess specialized glutamate receptors which are coupled via a G-protein to the control of a cyclic GMP (cGMP) cascade. Whole-cell voltage clamp recordings were obtained from light-responsive on-bipolar cells in retinal slices of the dogfish. Inclusion of nitroprusside in the patch-pipette solution induced effects in on-bipolar cells which were consistent with a rise in intracellular cGMP and thus stimulation of guanylate cyclase (GC) activity. Conversely, the soluble GC inhibitors, methylene blue and ferricyanide, induced effects consistent with a fall in intracellular cGMP. Activators of particulate GC had no effect. We conclude that cGMP synthesis in on-bipolar cells is catalysed by a NO-sensitive cyclase.
Physiology Department, University College London, UK.
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R
Shiells
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G
Falk
D000818:Animals; D000951:Antigens, Neoplasm / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D004284:Dogfish / Q000502:physiology*; D005136:Eye Proteins; D005292:Ferricyanides / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism*; D051597:Hippocalcin; D066298:In Vitro Techniques; D008074:Lipoproteins; D008751:Methylene Blue / Q000494:pharmacology; D009419:Nerve Tissue Proteins; D009569:Nitric Oxide / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D051603:Recoverin; D012160:Retina / Q000166:cytology* / Q000187:drug effects
D000951:Antigens, Neoplasm; D002135:Calcium-Binding Proteins; D005136:Eye Proteins; D005292:Ferricyanides; D008074:Lipoproteins; D009419:Nerve Tissue Proteins; C007931:hexacyanoferrate III; D051603:Recoverin; D051597:Hippocalcin; D009599:Nitroprusside; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D008751:Methylene Blue