Date of Award:

5-1960

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Watershed Sciences

Department name when degree awarded

Fishery Biology

Committee Chair(s)

William F. Sigler

Committee

William F. Sigler

Committee

John M. Neuhold

Committee

L. E. Olson

Committee

Raymond T. Sanders

Committee

Clyde Biddulph

Abstract

During the past quarter of a century there has been considerable investigation into the effects of fluorides on living organisms. It has been well established, as a result of these studies, that both small and elevated amounts of fluorides present in the environment may have a marked toxic effect upon gaining entry into the organism. Much of the research involving fluorides and the living organism has been confined to experimentation with animals, although considerable evidence indicates that plants are also subject to injury if fluorides are present in the atmosphere or the soil.

The great majority of the research dealing with effects of fluorides on animals has been confined to higher vertebrates, principally domestic farm species. The concentration of fluoride research in this area has been prompted by economic pressures arising from natural, industrial, or accidental fluoridation of livestock. For the most part, these investigations have been confined to determination of toxicity levels to various domestic species, while the mode of fluoride action upon living organisms has often been neglected. Some investigators, however, have postulated "defense mechanisms" within the organism whereby active fluoride ion is removed from systemic circulation and is either deposited in less active tissues of the body, or, is excreted in some manner. Such mechanisms would offer a degree of temporary protection of the organism from harmful effects of the fluoride ion.

Within recent years, with the immediate economic problems of fluoridation having been allayed to a considerable degree, there has been a tendency toward basic research in fluoride investigations. This tendency has been manifested in the design of experiments to seek out the nature and mechanism of fluoride action in the organism. Although earlier workers had suggested the possibility of enzyme inactivation, results of recent research indicate that the primary point of attack of fluorides is on enzyme systems of the organism. It may be that there is a gradual, cumulative destruction of enzymes whereby the enzyme-protein complex combines with fluoride ion and, as a result, is altered in some manner. It has been shown that fluoride ion forms stable complexes with certain divalent cations which are required to activate some enzymes. These processes may bring about a gradual cessation of metabolic reactions upon which life depends.

Within very recent years, research has been directed toward assessing the effects of fluorides on some wildlife species. Knowledge that naturally or industrially fluoridated waters may have deleterious effects on aquatic biota has stimulated research in this area. Thus far, research in this realm has dealt primarily with the effects of fluorides on several species of freshwater fishes. The ultimate concern of these projects is the accumulation of sufficient knowledge to assess accurately the effects of fluorides in aquatic environments on fish populations.

In my study, the effects of an artificially fluoridated medium on serum protein levels, serum protein fraction concentrations, alkaline phosphatase activity of the serum, and serum concentrations of calcium and magnesium ions were investigated in the attempt to uncover some of the effects that fluoride ion has on the rainbow trout, Salmo gairdneri Linnaeus.

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