The role of dietary vitamin A in mechanisms of cataract development in the teleost lumpfish

Deering, Margret (2023) The role of dietary vitamin A in mechanisms of cataract development in the teleost lumpfish. Masters thesis, Memorial University of Newfoundland.

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Lumpfish are highly prone to cataract development in the wild and in culture. There is evidence that cataract in farmed fish is related to nutrition. However, both the nutrients and the mechanisms involved in cataract development in lumpfish are not clear. Here, I investigated the mechanisms involved and the role of dietary vitamin A in cataract development in a cultured lumpfish population. Cultured lumpfish were fed three diets differing only in vitamin A supplementation level (5,000, 15,000 and 120,000 IU/kg) over an 18-month period, and fish growth, cataract rates and severities were determined. Western blotting and immunohistochemistry were performed on lens tissue to measure levels of 4-HNE, a marker of oxidative stress, and cleaved caspase-3, a marker of apoptosis. The diet with the lowest concentration of vitamin A reduced cataract rates and severity, and increased weight gain in males. 4- HNE levels in the lens were positively correlated with vitamin A intake. Cleaved caspase-3 was detected at high levels in lenses with severe cataract. 4-HNE and cleaved caspase-3 levels were highest in regions of the lens with severe, advanced cataract pathology when compared to regions with no visible pathology. Results suggest that higher vitamin A intake contributes cataract development through an oxidative stress pathway, and both oxidative stress and apoptosis are involved in advanced stages of cataract in lumpfish.

Item Type: Thesis (Masters)
Item ID: 16169
Additional Information: Includes bibliographical references -- Restricted until September 1, 2025
Keywords: lumpfish, cataract, vitamin A, oxidative stress, apoptosis
Department(s): Medicine, Faculty of > Biomedical Sciences
Date: October 2023
Date Type: Submission
Digital Object Identifier (DOI):
Medical Subject Heading: Fishes--anatomy & histology; Fish Diseases; Cataract--diet therapy; Immunohistochemistry; Oxidative Stress; Animal Nutritional Physiological Phenomena; Apoptosis

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