THE PORPHYROPSIN VISUAL SYSTEM
نویسندگان
چکیده
منابع مشابه
The Porphyropsin Visual System
1. In the rods of fresh-water and some anadromous fishes, rhodopsin is replaced by the purple photolabile pigment porphyropsin. This participates in a retinal cycle identical in form with that of rhodopsin, but in which new carotenoids replace retinene and vitamin A. 2. Porphyropsin possesses a broad absorption maximum at 522 +/- 2 mmicro, and perhaps a minimum at about 430 mmicro. The vitamin ...
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Though it had been supposed earlier that the bullfrog undergoes a virtually complete metamorphosis of visual systems from vitamin A(2) and porphyropsin in the tadpole to vitamin A(1) and rhodopsin in the adult, the present observations show that the retina of the adult frog may contain as much as 30-40% porphyropsin, all of it segregated in the dorsal zone. The most dorsal quarter of the adult ...
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Goldfish with retinas rich in either rhodopsin or porphyropsin were illuminated with bright light and then placed in the dark room to allow visual pigment regeneration. The kinetics of this in vivo pigment regeneration were followed by sampling these animals at regular time intervals. The first-order kinetic rate constant for the initial period of porphyropsin regeneration at 20 degrees C was 8...
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Weanling, male albino mice were placed on a vitamin A-free diet for three months to deplete their vitamin A stores. The vitamin A-deficient mice were injected intraperitoneally with all-trans 3-dehydroretinol. 3-dehydroretinol was rapidly incorporated into the liver as a fatty acid ester. The chromophore of visual pigment increased gradually and reached a normal level 13 days after the injectio...
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ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 1939
ISSN: 1540-7748,0022-1295
DOI: 10.1085/jgp.22.6.775