July 1983
Volume 24, Issue 7
Articles  |   July 1983
Both rod and cone disc shedding are related to light onset in the cat.
Investigative Ophthalmology & Visual Science July 1983, Vol.24, 844-856. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      S K Fisher, B A Pfeffer, D H Anderson; Both rod and cone disc shedding are related to light onset in the cat.. Invest. Ophthalmol. Vis. Sci. 1983;24(7):844-856.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements
This content is PDF only. Please click on the PDF icon to access.

Nineteen domestic cats were entrained to a 12-hr light/12-hr dark lighting cycle and killed at different times of the cycle. The numbers of rod and cone phagosomes in the retinal pigment epithelium (RPE) were quantified by light microscopy. The number of both rod and cone phagosomes shows a large increase within 2 hrs after light onset. Thereafter, the phagosome count remains low until the latter part of the dark period when the number of rod and cone phagosomes increases slightly. In a few cases, substantial variability in phagosome numbers was found between animals killed at the same times in the lighting cycle. Small (0.4-0.8 microns), dense, membrane-bound granules, that have the ultrastructural features of lysosomes, occur in large numbers in the tapetal RPE cells. The granules may contain only a homogeneous matrix or matrix plus membrane fragments or melanin. Variations in the number of such granules in different animals shows no clear diurnal pattern. Phagosome number, size, and length measurements of outer segments are used to provide estimates of cone outer segment turnover time in the cat.


This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.