| Literature DB >> 14610664 |
Robert Gábriel1, Joseph Lesauter, Tamás Bánvölgyi, György Petrovics, Rae Silver, Paul Witkovsky.
Abstract
We investigated parvalbumin immunoreactivity (PA-IR) in the retinas of rats maintained on a 12:12 h light:dark cycle, or after being placed in constant darkness for 24-72 h. Retinas were harvested at zeitgeber and circadian times 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 h. PA-IR was found primarily in retinal amacrine cells of the AII subtype. In a light/dark cycle, PA-IR showed a clear rhythm, with a low near zeitgeber time (ZT) 10:00 h and a peak near ZT 18:00 h. The ratio of immunofluorescence intensities at these timepoints was >15-fold. When animals were kept in complete darkness for 1-3 days, the rhythm of PA-IR was still preserved, but was progressively reduced in amplitude. The rhythm of PA-IR inferred from immunohistochemical data was confirmed by Western blots. We conclude that PA-IR in the rat retina shows an underlying circadian rhythm that is enhanced by cyclic light. The regulation may involve translocation of the protein between cell compartments and/or new protein synthesis.Entities:
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Year: 2003 PMID： 14610664 PMCID： PMC3271844 DOI： 10.1007/s00441-003-0785-2
Source DB: PubMed Journal: Cell Tissue Res ISSN： 0302-766X Impact factor: 5.249