Purchase this article with an account.
AM Petrosian, JE Haroutounian; Tauret and its Possible Application in the Opthalmology . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1408.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To understand why known since 70s, cats fed taurine deficient-diets became blind, why taurine is the most abundant amino-acid in the retina or light stimulates its release from ROS, we have suggested, that taurine is closely related with retinoids transport in the retina. To check this hypothesis, retinylidentaurine - tauret has been synthesized. This study has been carried to evaluate the existence and the function of tauret in the retina and to estimate its possibile application for ophthalmology. Methods: Studies have been carried mainly on frogs Rana ridibunda or temporaria. HPLC systems have been developed for identification and separation of tauret. 3H-taurine has been used to clarify the possibility of tauret synthesis in the eye. Transmission and scanning electron microscopy with X-ray microanalysis allows to identify the ways of tauret's transportation in the retina. Microspectrophotometric measurements allow the measurement of rhodopsin in the single, dark and bleached ROS. Results: By 3 different HPLC systems and by TLC we demonstrated tauret, lmax = 364nm, is an endogenous substance at the micromolar range and can be synthesized from 3H-taurine in the retina and pigment epithelium Tauret converts active 11-cis and bleached all-trans retinals into transportable, water soluble forms and after hydrolysis, half-life period 7 minute 11-cis retinal can be released free and incorporated into rhodopsin. Microspectrophotometric measurements confirmed a complete regeneration of rhodopsin in the ROSs when isolated frog retina after bleaching has been incubated in darkness in a physiological solution containing 11-cis tauret. It was established, that connections between disks and plasma membrane in the ROSs are behaving like retinoid-selective molecular channels and tauret can penetrate selectively from the extracellular space into intradisk spaces of ROSs. Upon elevation of calcium concentration in the medium over several mMs the channels closed. Conclusion: Taurine forms a water soluble complex with both forms of retinals. The key role it appears to play in the photoreceptor cells is related with regeneration of rhodopsin and removal of dangerous all-trans retinal. Both processes may underlie the protection mechanism against light-induced damage in emergency situations. During eye operations, when strong light from surgical microscope or lasers are destructive and limit surgical potential, application of 11-cis tauret can be invaluable in preventing eye structures from light-induced destruction.
This PDF is available to Subscribers Only