Abstract
Purified suspensions of frog rod outer segments still attached to the mitochondria-rich inner segment portion of the receptor cell (OS-IS) can be obtained in quantities (0.1 mg/retina) sufficient for chemical analysis. In oxygenated glucose-bicarbonate Ringer's medium with added Percoll, they display normal dark currents, light sensitivity, and photocurrent kinetics for several hours. Two millimolar cytoplasmic levels of ATP and GTP are maintained, fivefold higher than in isolated OS. The levels are not altered by abolition of the dark current with ouabain. Nucleoside triphosphates are more effectively buffered than in isolated OS, and their levels remain constant during changes in external calcium levels. 32Pi is incorporated into endogenous ATP and GTP pools twice as efficiently as in isolated OS, and is used in the phosphorylation of rhodopsin. OS-IS take up and release 45Ca++ by Na+-, Ca++-, and IBMX-sensitive mechanisms. Illumination causes release of 45Ca++, which confirms retinal studies by other groups using Ca++- sensitive electrodes. Thus, OS-IS suspensions model the behavior of photoreceptors still attached to the living retina. Their availability permits the simultaneous assay and correlation of electrophysiological and chemical changes occurring during excitation and adaptation.
Full Text
The Full Text of this article is available as a PDF (1.4 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bader C. R., Macleish P. R., Schwartz E. A. A voltage-clamp study of the light response in solitary rods of the tiger salamander. J Physiol. 1979 Nov;296:1–26. doi: 10.1113/jphysiol.1979.sp012988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bastian B. L., Fain G. L. The effects of sodium replacement on the responses of toad rods. J Physiol. 1982 Sep;330:331–347. doi: 10.1113/jphysiol.1982.sp014344. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baylor D. A., Lamb T. D., Yau K. W. The membrane current of single rod outer segments. J Physiol. 1979 Mar;288:589–611. [PMC free article] [PubMed] [Google Scholar]
- Berger S. J., DeVries G. W., Carter J. G., Schulz D. W., Passonneau P. N., Lowry O. H., Ferrendelli J. A. The distribution of the components of the cyclic GMP cycle in retina. J Biol Chem. 1980 Apr 10;255(7):3128–3133. [PubMed] [Google Scholar]
- Biernbaum M. S., Bownds M. D. Influence of light and calcium on guanosine 5'-triphosphate in isolated frog rod outer segments. J Gen Physiol. 1979 Dec;74(6):649–669. doi: 10.1085/jgp.74.6.649. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Biernbaum M. S., Bownds M. D. Light-induced changes in GTP and ATP in frog rod photoreceptors. Comparison with recovery of dark current and light sensitivity during dark adaptation. J Gen Physiol. 1985 Jan;85(1):107–121. doi: 10.1085/jgp.85.1.107. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bownds D., Brodie A. E. Light-sensitive swelling of isolated frog rod outer segments as an in vitro assay for visual transduction and dark adaptation. J Gen Physiol. 1975 Oct;66(4):407–425. doi: 10.1085/jgp.66.4.407. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bownds D., Gordon-Walker A., Gaide-Huguenin A. C., Robinson W. Characterization and analysis of frog photoreceptor membranes. J Gen Physiol. 1971 Sep;58(3):225–237. doi: 10.1085/jgp.58.3.225. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brodie A. E., Bownds D. Biochemical correlates of adaptation processes in isolated frog photoreceptor membranes. J Gen Physiol. 1976 Jul;68(1):1–11. doi: 10.1085/jgp.68.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Capovilla M., Cervetto L., Torre V. The effect of phosphodiesterase inhibitors on the electrical activity of toad rods. J Physiol. 1983 Oct;343:277–294. doi: 10.1113/jphysiol.1983.sp014892. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caretta A., Cavaggioni A. Fast ionic flux activated by cyclic GMP in the membrane of cattle rod outer segments. Eur J Biochem. 1983 Apr 15;132(1):1–8. doi: 10.1111/j.1432-1033.1983.tb07317.x. [DOI] [PubMed] [Google Scholar]
- Cote R. H., Biernbaum M. S., Nicol G. D., Bownds M. D. Light-induced decreases in cGMP concentration precede changes in membrane permeability in frog rod photoreceptors. J Biol Chem. 1984 Aug 10;259(15):9635–9641. [PubMed] [Google Scholar]
- George J. S., Hagins W. A. Control of Ca2+ in rod outer segment disks by light and cyclic GMP. Nature. 1983 May 26;303(5915):344–348. doi: 10.1038/303344a0. [DOI] [PubMed] [Google Scholar]
- Gold G. H., Korenbrot J. I. Light-induced calcium release by intact retinal rods. Proc Natl Acad Sci U S A. 1980 Sep;77(9):5557–5561. doi: 10.1073/pnas.77.9.5557. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hagins W. A., Penn R. D., Yoshikami S. Dark current and photocurrent in retinal rods. Biophys J. 1970 May;10(5):380–412. doi: 10.1016/S0006-3495(70)86308-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hermolin J., Karell M. A., Hamm H. E., Bownds M. D. Calcium and cyclic GMP regulation of light-sensitive protein phosphorylation in frog photoreceptor membranes. J Gen Physiol. 1982 Apr;79(4):633–655. doi: 10.1085/jgp.79.4.633. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kavipurapu P. R., Farber D. B., Lolley R. N. Degradation and resynthesis of cyclic 3', 5' -guanosine monophosphate in truncated rod photoreceptors from bovine retina. Exp Eye Res. 1982 Feb;34(2):181–189. doi: 10.1016/0014-4835(82)90052-5. [DOI] [PubMed] [Google Scholar]
- Kawamura S., Bownds M. D. Light adaption of the cyclic GMP phosphodiesterase of frog photoreceptor membranes mediated by ATP and calcium ions. J Gen Physiol. 1981 May;77(5):571–591. doi: 10.1085/jgp.77.5.571. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Korenbrot J. I., Cone R. A. Dark ionic flux and the effects of light in isolated rod outer segments. J Gen Physiol. 1972 Jul;60(1):20–45. doi: 10.1085/jgp.60.1.20. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lamb T. D., McNaughton P. A., Yau K. W. Spatial spread of activation and background desensitization in toad rod outer segments. J Physiol. 1981;319:463–496. doi: 10.1113/jphysiol.1981.sp013921. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Liebman P. A., Entine G. Visual pigments of frog and tadpole (Rana pipiens). Vision Res. 1968 Jul;8(7):761–775. doi: 10.1016/0042-6989(68)90128-4. [DOI] [PubMed] [Google Scholar]
- Liebman P. A., Mueller P., Pugh E. N., Jr Protons suppress the dark current of frog retinal rods. J Physiol. 1984 Feb;347:85–110. doi: 10.1113/jphysiol.1984.sp015055. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mandel P. Free nucleotides in animal tissues. Prog Nucleic Acid Res Mol Biol. 1964;3:299–334. doi: 10.1016/s0079-6603(08)60744-8. [DOI] [PubMed] [Google Scholar]
- Miki N., Kuo C. H., Hayashi Y., Akiyama M. Functional role of calcium in photoreceptor cells. Photochem Photobiol. 1980 Oct;32(4):503–508. doi: 10.1111/j.1751-1097.1980.tb03795.x. [DOI] [PubMed] [Google Scholar]
- Polans A. S., Hermolin J., Bownds M. D. Light-induced dephosphorylation of two proteins in frog rod outer segments: influence of cyclic nucleotides and calcium. J Gen Physiol. 1979 Nov;74(5):595–613. doi: 10.1085/jgp.74.5.595. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Polans A. S., Kawamura S., Bownds M. D. Influence of calcium on guanosine 3',5'-cyclic monophosphate levels in frog rod outer segments. J Gen Physiol. 1981 Jan;77(1):41–48. doi: 10.1085/jgp.77.1.41. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robinson P. R., Kawamura S., Abramson B., Bownds M. D. Control of the cyclic GMP phosphodiesterase of frog photoreceptor membranes. J Gen Physiol. 1980 Nov;76(5):631–645. doi: 10.1085/jgp.76.5.631. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robinson W. E., Hagins W. A. GTP hydrolysis in intact rod outer segments and the transmitter cycle in visual excitation. Nature. 1979 Aug 2;280(5721):398–400. doi: 10.1038/280398a0. [DOI] [PubMed] [Google Scholar]
- Schnapf J. L. Dependence of the single photon response on longitudinal position of absorption in toad rod outer segments. J Physiol. 1983 Oct;343:147–159. doi: 10.1113/jphysiol.1983.sp014886. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schnetkamp P. P. Calcium translocation and storage of isolated intact cattle rod outer segments in darkness. Biochim Biophys Acta. 1979 Jul 5;554(2):441–459. doi: 10.1016/0005-2736(79)90383-3. [DOI] [PubMed] [Google Scholar]
- Schnetkamp P. P., Daemen F. J., Bonting S. L. Biochemical aspects of the visual process. XXXVI. Calcium accumulation in cattle rod outer segments: evidence for a calcium-sodium exchange carrier in the rod sac membrane. Biochim Biophys Acta. 1977 Jul 14;468(2):259–270. doi: 10.1016/0005-2736(77)90119-5. [DOI] [PubMed] [Google Scholar]
- Schnetkamp P. P., Daemen F. J. Transfer of high-energy phosphate in bovine rod outer segments. A nucleotide buffer system. Biochim Biophys Acta. 1981 Feb 5;672(3):307–312. doi: 10.1016/0304-4165(81)90298-1. [DOI] [PubMed] [Google Scholar]
- Schnetkamp P. P. Ion selectivity of the cation transport system of isolated intact cattle rod outer segments: evidence for a direct communication between the rod plasma membrane and the rod disk membranes. Biochim Biophys Acta. 1980 May 8;598(1):66–90. doi: 10.1016/0005-2736(80)90266-7. [DOI] [PubMed] [Google Scholar]
- Schröder W. H., Fain G. L. Light-dependent calcium release from photoreceptors measured by laser micro-mass analysis. Nature. 1984 May 17;309(5965):268–270. doi: 10.1038/309268a0. [DOI] [PubMed] [Google Scholar]
- Stirling C. E., Lee A. [3H]ouabain autoradiography of frog retina. J Cell Biol. 1980 May;85(2):313–324. doi: 10.1083/jcb.85.2.313. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Szuts E. Z. Calcium flux across disk membranes. Studies with intact rod photoreceptors and purified disks. J Gen Physiol. 1980 Sep;76(3):253–286. doi: 10.1085/jgp.76.3.253. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Witkovsky P., Yang C. Y. Transport and phosphorylation of 2-deoxy-D-glucose by amphibian retina. Effects of light and darkness. J Gen Physiol. 1982 Aug;80(2):173–190. doi: 10.1085/jgp.80.2.173. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Woodruff M. L., Bownds D., Green S. H., Morrisey J. L., Shedlovsky A. Guanosine 3',5'-cyclic monophosphate and the in vitro physiology of frog photoreceptor membranes. J Gen Physiol. 1977 May;69(5):667–679. doi: 10.1085/jgp.69.5.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Woodruff M. L., Bownds M. D. Amplitude, kinetics, and reversibility of a light-induced decrease in guanosine 3',5'-cyclic monophosphate in frog photoreceptor membranes. J Gen Physiol. 1979 May;73(5):629–653. doi: 10.1085/jgp.73.5.629. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yau K. W., McNaughton P. A., Hodgkin A. L. Effect of ions on the light-sensitive current in retinal rods. Nature. 1981 Aug 6;292(5823):502–505. doi: 10.1038/292502a0. [DOI] [PubMed] [Google Scholar]
- Yoshikami S., George J. S., Hagins W. A. Light-induced calcium fluxes from outer segment layer of vertebrate retinas. Nature. 1980 Jul 24;286(5771):395–398. doi: 10.1038/286395a0. [DOI] [PubMed] [Google Scholar]
- Yoshikami S., Robinson W. E., Hagins W. A. Topology of the outer segment membranes of retinal rods and cones revealed by a fluorescent probe. Science. 1974 Sep 27;185(4157):1176–1179. doi: 10.1126/science.185.4157.1176. [DOI] [PubMed] [Google Scholar]
- de Azeredo F. A., Lust W. D., Passonneau J. V. Light-induced changes in energy metabolites, guanine nucleotides, and guanylate cyclase within frog retinal layers. J Biol Chem. 1981 Mar 25;256(6):2731–2735. [PubMed] [Google Scholar]