Topic
Dehydroretinal
About: Dehydroretinal is a research topic. Over the lifetime, 8 publications have been published within this topic receiving 100 citations.
Papers
TL;DR: The temperature effects on A2 pigments were similar to those described previously for the A1 pigment of toad "red" rods, but warming caused an increase in relative sensitivities at very long wavelengths but additionally a small shift of lambdamax toward shorter wavelengths.
Abstract: Effects of temperature on the spectral properties of visual pigments were measured in the physiological range (5‐288C) in photoreceptor cells of bullfrog ( Rana catesbeiana) and crucian carp (Carassius carassius). Absorbance spectra recorded by microspectrophotometry (MSP) in single cells and sensitivity spectra recorded by electroretinography (ERG) across the isolated retina were combined to yield accurate composite spectra from ca. 400 nm to 800 nm. The four photoreceptor types selected for study allowed three comparisons illuminating the properties of pigments using the dehydroretinal (A2) chromophore: (1) the two members of an A10A2 pigment pair with the same opsin (porphyropsin vs. rhodopsin in bullfrog “red” rods); (2) two A2 pigments with similar spectra (porphyropsin rods of bullfrog and crucian carp); and (3) two A2 pigments with different spectra (rods vs. long-wavelength-sensitive (L-) cones of crucian carp). Qualitatively, the temperature effects on A2 pigments were similar to those described previously for the A1 pigment of toad “red” rods. Warming caused an increase in relative sensitivities at very long wavelengths but additionally a small shift of lmax toward shorter wavelengths. The former effect was used for estimating the minimum energy required for photoactivation ~Ea) of the pigment. Bullfrog rod opsin with A2 chromophore had Ea 5 44.2 6 0.9 kcal0mol, significantly lower (one-tailed P , 0.05) than the value Ea 5 46.5 6 0.8 kcal0mol for the same opsin coupled to A1. The A2 rod pigment of crucian carp had Ea 5 42.3 6 0.6 kcal0mol, which is significantly higher (one-tailed P , 0.01) than that of the L-cones in the same retina ~Ea 5 38.3 6 0.4 kcal0mol), whereas the difference compared with the bullfrog A2 rod pigment is not statistically significant (two-tailed P 5 0.13). No strict connection between lmax and Ea appears to exist among A2 pigments any more than among A1 pigments. Still, the A1 r A2 chromophore substitution in bullfrog opsin causes three changes correlated as originally hypothesized by Barlow (1957): a red-shift of lmax, a decrease in Ea, and an increase in thermal noise.
20 citations
TL;DR: The mobilization of retinal in the fowl appears to be controlled by hormones specifically to provide a supply for the eggs, or for egg production.
13 citations
TL;DR: This chapter discusses the quantitative analysis of retinal and 3-dehydroretinal by high-pressure liquid Chromatography, and describes the extraction procedure, high-performance liquid chromatography (HPLC), comparison with a conventional method, and applications to biological materials.
Abstract: Publisher Summary This chapter discusses the quantitative analysis of retinal and 3-dehydroretinal by high-pressure liquid chromatography, and describes the extraction procedure, high-performance liquid chromatography (HPLC), comparison with a conventional method, and applications to biological materials To quantitate retinal and 3-dehydroretinal, a standard mixture of retinaloxime and 3-dehydroretinaloxime at known concentration is required In the retina, usually, 11- cis and all -trans isomers of retinal (and 3- dehydroretinal) are present as the chromophores of the visual pigment Therefore, a standard mixture of 11- cis -retinal, 11 -cis -3-dehydroretinal , all- trans -retinal, and all- trans -3-dehydroretinal is sufficient for the usual analysis of visual pigment These four compounds are easily obtained in high purity by HPLC using a silica gel column The purified isomer is dissolved in ethanol and the concentration is determined by a spectrophotometer using the value of the absorption coefficient reported Standard oximes are prepared HPLC is performed with normal phase-silica gel column Good separation is obtained with spherical particle of porous silica gel with 5 or 7 μ m diameter The mobile phase one usually uses is 7% diethyl ether in n-hexane containing 0075% ethanol (v/v) The reliability of the HPLC method is evaluated by comparing the results of HPLC with the composition of the visual pigment extracted with detergent The adult bullfrog has rhodopsin and porphyropsin in the retina and porphyropsin is localized in a dorsal half of the retina Suitable materials are obtained by separating the bullfrog retina into dorsal and ventral parts
12 citations
TL;DR: Cod from the Arcto-Norwegian stock were caught during their gonadal maturation cycle, and plasma samples from individual fish obtained for the determination of total calcium and vitamin A aldehyde.
Abstract: Cod ( Gadus morhua L.) from the Arcto-Norwegian stock were caught during their gonadal maturation cycle, and plasma samples from individual fish obtained for the determination of total calcium and vitamin A aldehyde (retinal + dehydroretinal). The concentrations of these two substances in the plasma of female cod caught during January–March were significantly correlated r = 0·728, P
5 citations
TL;DR: The results indicate that 3-dehydroretinol is not converted to retinol in mouse and is used less efficiently than Retinol for the chromophore of visual pigment.
4 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2003 | 1 |
| 1997 | 1 |
| 1994 | 1 |
| 1988 | 1 |
| 1986 | 1 |
| 1974 | 1 |