Influence of light and calcium on guanosine 5'-triphosphate in isolated frog rod outer segments.

Biernbaum, Michael S.; Bownds, M D

doi:10.1085/jgp.74.6.649

Cited by 57 publications

(38 citation statements)

References 21 publications

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“…It was not the purpose of this investigation to explore possible functions of cyclic AMP in photoreceptor transduction or adaptation, but Lipton et al (1977) did find some physiological evidence for a possible antagonism of the cyclic AMP and cyclic GMP systems in photoreceptors, and the possible role of cyclic GMP in transduction and/or adaptation is under active investigation (Yee and Liebman, 1978;Liebman and Pugh, 1979;Woodruff and Bownds, 1979;Biernbaum and Bownds, 1979;Kilbride, 1980;Kawamura and Bownds, 1981).…”

Section: Discussionmentioning

confidence: 99%

Increased Levels of 3′,5′‐Cyclic Adenosine Monophosphate Induced by Cobaltous Ion or 3‐Isobutylmethylxanthine in the Incubated Mouse Retina: Evidence Concerning Location and Response to Ions and Light

Cohen

1982

Journal of Neurochemistry

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Dark levels of 3',5'-cyclic adenosine monophosphate (cyclic AMP) of mouse retinas incubated in Earle's medium were elevated by 3-isobutyl-methylxanthine (IBMX) and/or Co2+ or Mn2+, but not by Cd2+, methylverapamil, or excess Mg2+ of Ca2+. Light reduced elevated dark levels of cyclic AMP in the presence of agents known to block the light modulation of post-receptoral neurons (aspartate, Co2+, high Mg2+), a finding consistent with a cyclic AMP metabolism in photoreceptors. Co2+-elevated cyclic AMP levels were not less light-sensitive than cyclic GMP levels. Ouabain substantially increased IBMX-elevated cyclic AMP with a persistent light response, but reduced the dark action of Co2+. IBMX, but not Co2+, also increased cyclic AMP in receptorless (rd/rd) retinas; haloperidol partly reduced this IBMX effect. In normal retinas in Co2+ medium, progressively replacing Na+ by K+ (but not choline+) from 1--50 mM caused a progressive fall in dark, light-sensitive cyclic AMP levels, but from 50 to 100 mM-K+ there appeared haloperidol-preventable increases in both the dark- and light-insensitive levels of cyclic AMP. In IBMX-aspartate medium a haloperidol-preventable, light-insensitive increase in cyclic AMP appeared from 20 mM-K+ upwards. Haloperidol-preventable increases in cyclic AMP as induced by high K+ required Co2+ in normal retinas, but not in receptorless retinas, and 5 nM-Co2+ greatly increased the response to dopamine in receptorless retinas. The post-dopaminergic neurons, which are 4th-order neurons, may have become hypersensitive to dopamine in receptorless retinas consequent to the absent signal from the 1st-order photoreceptors, or directly, as an effect of the same gene underlying the dystrophy.

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Section: Discussionmentioning

confidence: 99%

Increased Levels of 3′,5′‐Cyclic Adenosine Monophosphate Induced by Cobaltous Ion or 3‐Isobutylmethylxanthine in the Incubated Mouse Retina: Evidence Concerning Location and Response to Ions and Light

Cohen

1982

Journal of Neurochemistry

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“…To better assess the importance of the phosphorylation of rhodopsin and other proteins, as well as the effects of cyclic GMP and Ca++ , it would be desirable to study this chemistry in a preparation that maintains normal physiological function . Neither the permeabilized outer segments used in this study nor the intact outer segments used to measure nucleotide changes (Woodruff et al ., 1977 ;Biernbaum and Bownds, 1979) maintain the ability to perform normal conductance and adaptation changes. We have recently developed procedures that permit isolation of pure suspensions of outer segments still attached to the mitochondria-rich inner segment .…”

Section: Rhodopsin Phosphorylationmentioning

confidence: 99%

“…GENERAL PHYSIOLOGY " VOLUME 79 " 1982 X 104 rhodopsin molecules per outer segment were bleached (of the total of 3 X 109 rhodopsins present in each outer segment) . Thus, this reaction is not detectable at light intensities where many other light-induced reactions have been recently characterized : a GTP decrease(Biernbaum and Bownds, 1979),…”

mentioning

confidence: 96%

Calcium and cyclic GMP regulation of light-sensitive protein phosphorylation in frog photoreceptor membranes.

Hermolin¹,

Karell²,

Hamm³

et al. 1982

The Journal of General Physiology

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100

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In frog photoreceptor membranes, light induces a dephosphorylation of two small proteins and a phosphorylation of rhodopsin . The level of phosphorylation of the two small proteins is influenced by cyclic GMP . Measurement of their phosphorylation as a function of cyclic GMP concentration shows fivefold stimulation as cyclic GMP is increased from 10 -5 to 10-3 M . This includes the concentration range over which light activation of a cyclic GMP phosphodiesterase causes cyclic GMP levels to fall in vivo . Cyclic AMP does not affect the phosphorylations . Calcium ions inhibit the phosphorylation reactions . Calcium inhibits the cyclic GMP-stimulated phosphorylation of the small proteins as its concentration is increased from 10 -s to 10 -3 M, with maximal inhibition of 70% being observed . Rhodopsin phosphorylation is not stimulated by cyclic nucleotides, but is inhibited by calcium, with 50% inhibition being observed as the Ca" concentration is increased from 10-9 to 10-3 M . A nucleotide binding site appears to regulate rhodopsin phosphorylation . Several properties of the rhodopsin phosphorylation suggest that it does not play a role in a rapid ATP-dependent regulation of the cyclic GMP pathway . Calcium inhibition of protein phosphorylation is a distinctive feature of this system, and it is suggested that Ca" regulation of protein phosphorylation plays a role in the visual adaptation process . Furthermore, the data provide support for the idea that calcium and cyclic GMP pathways interact in regulating the lightsensitive conductance .

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“…Earlier studies on the effects of light on phosphorus metabolites, all of which have used chemical analysis techniques, have yielded contradictory results: Robinson & Hagins (1979b), de Azeredo, Lust & Passonneau (1980), Winkler (1981), Goldberg, Adelbert, Gander & Walseth (1983), and Biernbaum & Bownds (1979, 1985 all report that the retinal ATP content does not change in light; Mitzel, Hall, DeVries, Cohen & Ferrendelli (1978) show ATP increases during long incubations in light; Sickel (1972), Carretta & Cavaggioni (1976), and Ostroy, Svoboda & Wilson (1990) report decreases in ATP levels in light. In addition, Mitzel et al (1978) and de Azeredo et al (1981) report increases in phosphocreatine (PCr) levels in light, while Sickel (1972) finds a decrease.…”

Section: Introductionmentioning

confidence: 99%

Decreased energy requirement of toad retina during light adaptation as demonstrated by 31P nuclear magnetic resonance.

Apte

Ebrey

Dawson

1993

The Journal of Physiology

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SUMMARY1. The effect of light and dark adaptation on the levels of phosphorus metabolites (nucleotide di-and triphosphates, phosphocreatine, pyridine nucleotide, inorganic phosphate, phosphodiesters, phosphomonoesters, and uridine diphosphate-glucose) in the toad (Bufo marinus) retina and retinal extracts was studied by 31P nuclear magnetic resonance (NMR) spectroscopy.2. Spectra were acquired using an NMR probe specifically designed for superfusion and illumination of a single retina. Retinae were maintained at a steady state for up to 10 h in an electrolyte solution containing 10 mm Hepes buffer and bubbled with 98% 02-2 % C02, pH 7-8 at 20°C.3. The intracellular concentrations of the phosphorus metabolites were measured in total darkness or during prolonged exposure to light. The concentration of nucleoside triphosphates (NTP) in the dark-adapted retina was about 1P5 mm and that of phosphocreatine (PCr) was about 0 7 mM.4. In saturating levels of light, 6-0 x 1011 or 1P5 x 1013 quanta s-1 cm-2 at 520 nm, the levels of PCr and phosphomonoesters rose, the levels of NTP and protons (pH) were maintained, and the levels of pyridine nucleotides and nucleotide diphosphates (NDP) fell.5. A rise in the level of PCr in the presence of an unchanged level of NTP in the light-adapted retina indicates that the energy consumption of the retina is greater in the dark.6. These results are in agreement with the results of oxygen consumption, glucose dependence, and electrophysiological studies which also indicate that the metabolic energy requirement of the retina decreases in light.

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Influence of light and calcium on guanosine 5'-triphosphate in isolated frog rod outer segments.

Cited by 57 publications

References 21 publications

Increased Levels of 3′,5′‐Cyclic Adenosine Monophosphate Induced by Cobaltous Ion or 3‐Isobutylmethylxanthine in the Incubated Mouse Retina: Evidence Concerning Location and Response to Ions and Light

Increased Levels of 3′,5′‐Cyclic Adenosine Monophosphate Induced by Cobaltous Ion or 3‐Isobutylmethylxanthine in the Incubated Mouse Retina: Evidence Concerning Location and Response to Ions and Light

Calcium and cyclic GMP regulation of light-sensitive protein phosphorylation in frog photoreceptor membranes.

Decreased energy requirement of toad retina during light adaptation as demonstrated by 31P nuclear magnetic resonance.

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