Glenn M. Christensen

Toxic effects of cadmium on three generations of brook trout (Salvelinus fontinalis)

Abstract Three generations of brook trout (Salvelinus fontinalis) were exposed to several concentrations of total cadmium (0.06–6.4 μg Cd/liter). Significant numbers of first- and second-generation adult males died during spawning at 3.4 μg Cd/liter. This concentration also significantly retarded growth of juvenile second- and third-generation offspring. The maximum acceptable toxicant concentration (MATC) for brook trout exposed to cadmium in Lake Superior water (hardness 44 mg/liter as CaCO 3, pH 7–8) lies between 1.7 and 3.4 μg Cd/liter. Cadmium-residue analyses of kidney, liver, gill, gonad, spleen, muscle, and red blood cells frown first- and second- generation trout indicated that kidney, liver, and gill tissue accumulated the greatest amounts of cadmium at each water exposure concentration. No significant increases in cadmium were measured in edible muscle at any of the cadmium water concentrations tested. Cadmium residues in kidney, liver, and gill tissue of fish frown all exposure concentrations ...

Effects of water pollutants and other chemicals on fish acetylcholinesterase (in vitro)

Acetylcholinesterase (AChE) preparations from the muscle of the fathead minnow (Pimephales promelas Rafinesque) were treated (in vitro) with 74 chemicals of various classes, many of which are environmental contaminants, to determine their effect upon enzyme activity. A highly inhibitory effect was found with several carbamates, one organoxy-phosphate, the arsenite ion, and certain heavy metal cations. Intermediate inhibition was found with the arsenate ion, other metal cations, organometals, certain neuroactive agents, organophosphates, and one organochloride pesticide. Several organochloride pesticides, alkaline and alkaline—earth cations, a variety of anions, several drugs, and other chemicals had little inhibitory effect at the highest concentration used (0.01 m). The effect of chemicals in mixtures of known composition was approximately additive. None of the chemicals tested caused detectable enzyme activation.

Chemical effects on the activity of eight enzymes: A review and a discussion relevant to environmental monitoring

Abstract The effects of selected water pollutants and other chemicals on the activity of eight enzymes (in vitro) are summarized. The information may give insight into the mechanism of action of toxic chemicals and have application in the development of a rapid screening procedure involving enzymes as biomonitors in analyzing water quality.

Effect of selected water toxicants and other chemicals upon adenosine triphosphatase activity in vitro.

The current study was undertaken to improve and simplify a colorimetric procedure for the analysis of ATPase activity and to analyze 19 selected chemicals from structurally different chemical classes, most of which are water pollutants, rate them in accordance with degree of inhibitory effect, and make some judgement regarding which of these agents may cause toxic effects on the living animals through ATPase inhibition or activation. The most accurate assessment of sublethal foreign agent effects on animals ultimately may be derived from precisely measured molecular changes.

Effect of water pollutants and other chemicals upon ribonuclease activity in vitro

Ribonuclease was treated in vitro with 73 chemicals, many of which are environmental pollutants, including inorganic, organic, and metal-organic chemicals, pesticides and other biocides, alkyl and aryl industrial pollutants, and certain additional chemicals, to determine their effect upon enzyme activity. Palladium (II and IV) and gold (III) were the strongest inhibitors of RNase activity. Other strong inhibitors, in decreasing order of effect, were: sodium dodecyl sulfate, silver (I), EDTA, mercury (II), copper (II), thiram (fungicide), platinum (IV), malathion (pesticide), lead (II), and beryllium (II). Intermediate effects were found with other inorganic cations, many anions, and some other chemicals. A number of compounds of different chemical types caused no measurable effect. None of the chemicals tested caused a measurable activation of this enzyme.

Estimation of Live Fish Weight by Photography

Abstract Approximate weights offish were calculated from length and width measurements of their photographic images. In the calculations we employed the formula Wt = KLW², where Wt = weight (g); K = proportionality factor, derived from a subsample of the population under study; L = length (cm); and W = width (cm). When tested against true weights, the derived weights had a mean error of ±8.6%.