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DEVELOPMENTAL CHANGES IN CARBACHOL-STIMULATED INOSITOLPHOSPHATE RELEASE IN PIGMENTED RAT RETINA
Citation:
Tandon, P., C. Pope, S. Padilla, H. Tilson, AND G. Gore. DEVELOPMENTAL CHANGES IN CARBACHOL-STIMULATED INOSITOLPHOSPHATE RELEASE IN PIGMENTED RAT RETINA. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-94/035.
Description:
Muscarinic stimulation of inositolphosphate (IP) release in the albino rat retina changes during development. ittle is known, however, about the developmental profile of receptor-stimulated IP release in pigmented rat retina. arbachol-stimulated EP release was studied in the whole retina from Long-Evans rats of different ages (day 5, 10, 15, 20, adult) following in vitro incorporation of [3II]myoinositol. he pigmented retina is light-sensitive, making it necessary to dark adapt the animals and perform retinal dissections under low illumination in order to prevent light-induced EP release. etinae from postnatal day 10 rats showed the highest amount of carbachol-stimulated IP release. his response to carbachol decreased with age until postnatal day 20 when it reached adult levels. he pigmented rat retina showed a sharp fall in the degree of carbachol (100 uM)-stimulated IP release at the time of eye-opening (409% above basal in retina from 10 day old animals, as compared to 190% above basal in 15 day old retina). asal release of IP was not altered in the retina during development. uscarinic cholinergic receptor binding was, however, found to increase with age, reaching adult levels by PND 20. etinal weight and protein per retina also increased four fold from day 5 to adult; however, the in vitro incorporation of [3H]myo-inositol into phosphoinositides (calculated as per mg protein) did not change during development. hus, in animals prior to eye opening, a much higher proportion of be phosphoinositides appears to hydrolysed upon muscarinic receptor stimulation.