The effects of taurine deficiency on aspects of retinal cGMP metabolism were examined. Rats were made taurine deficient by the administration of 1% GES. The activities of the key enzymes of cGMP metabolism, phosphodiesterase and guanylate cyclase, were indirectly determined by the response of retinas to light and to low calcium. Dark-adapted retinas of rats treated with GES for 4 and 8 weeks exhibited significantly smaller decreases in cGMP in response to light exposure as compared to control retinas. Retinas from 4 and 8 week GES-treated rats also exhibited smaller increases in cGMP when they were exposed to 0.1nM calcium. In addition, dark-adapted retinas of 8 week GES-treated rats had 36% less cGMP than dark-adapted control retinas. Since a light-induced decrease of cGMP is of central importance in phototransduction, these results support the hypothesis that abnormalities in the retinal cGMP metabolism of taurine-deficient rats may account for the electro-retinographic deficits observed in these animals.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.59813 |
| Date | January 1990 |
| Creators | Acton, Joseph |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001124988, proquestno: AAIMM66418, Theses scanned by UMI/ProQuest. |
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