Abstract
Incorporation of [3H]inositol into phosphatidylinositol (Pl) in isolated rat retinas is enhanced by light and by the addition of cytidine to the incubation media. In retinas preincubated with [3H]inositol in dark, [3H]inositol was chased into Pl in light by addition of unlabeled cytidine and was chased out of Pl in light by addition of unlabeled cytidine plus inositol. Autoradiograms of retinas show a heavy density of silver grains over photoreceptor cell inner segments (with chase-in) and a loss of labeling (with chase-out). Exogenous cytidine and inositol were shown to enhance not only the turnover of Pl within photoreceptor cells but the synthesis of Pl as well; in media supplemented with these precursors, approximately 50% of [14C]glycerol and 25% of [32Pi]incorporated into lipid in light were associated with Pl. These results suggest that availability of both cytidine and inositol may play a role in the light-dependent changes in Pl metabolism within photoreceptor cells.
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Selected References
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- Anderson R. E., Hollyfield J. G. Light stimulates the incorporation of inositol into phosphatidylinositol in the retina. Biochim Biophys Acta. 1981 Sep 24;665(3):619–622. doi: 10.1016/0005-2760(81)90280-0. [DOI] [PubMed] [Google Scholar]
- Anderson R. E. Lipids of ocular tissues. IV. A comparison of the phospholipids from the retina of six mammalian species. Exp Eye Res. 1970 Oct;10(2):339–344. doi: 10.1016/s0014-4835(70)80046-x. [DOI] [PubMed] [Google Scholar]
- Benjamins J. A., Agranoff B. W. Distribution and properties of CDP-diglyceride:inositol transferase from brain. J Neurochem. 1969 Apr;16(4):513–527. doi: 10.1111/j.1471-4159.1969.tb06850.x. [DOI] [PubMed] [Google Scholar]
- Brammer M. J., Carey S. G. Incorporation of choline and inositol into phospholipids of isolated bovine oligodendrocyte perikarya. J Neurochem. 1980 Oct;35(4):873–879. doi: 10.1111/j.1471-4159.1980.tb07085.x. [DOI] [PubMed] [Google Scholar]
- Gould R. M., Dawson R. M. Incorporation of newly formed lecithin into peripheral nerve myelin. J Cell Biol. 1976 Mar;68(3):480–496. doi: 10.1083/jcb.68.3.480. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Prpić V., Blackmore P. F., Exton J. H. myo-Inositol uptake and metabolism in isolated rat liver cells. J Biol Chem. 1982 Oct 10;257(19):11315–11322. [PubMed] [Google Scholar]
- Schmidt S. Y. Cytidine metabolism in photoreceptor cells of the rat. J Cell Biol. 1983 Sep;97(3):824–831. doi: 10.1083/jcb.97.3.824. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schmidt S. Y. Light enhances the turnover of phosphatidylinositol in rat retinas. J Neurochem. 1983 Jun;40(6):1630–1638. doi: 10.1111/j.1471-4159.1983.tb08136.x. [DOI] [PubMed] [Google Scholar]
- Schmidt S. Y. Phosphatidylinositol synthesis and phosphorylation are enhanced by light in rat retinas. J Biol Chem. 1983 Jun 10;258(11):6863–6868. [PubMed] [Google Scholar]
- Takenawa T., Saito M., Nagai Y., Egawa K. Solubilization of the enzyme catalyzing CDP-diglyceride-independent incorporation of myo-inositol into phosphatidyl inositol and its comparison to CDP-diglyceride:inositol transferase. Arch Biochem Biophys. 1977 Jul;182(1):244–250. doi: 10.1016/0003-9861(77)90304-6. [DOI] [PubMed] [Google Scholar]