This method, based on the glucose oxidase enzymatic reaction, is highly 

 specific for glucose and required only 25 ul of serum. Replicate deter- 

 minations of each serum sample were performed. Total and esterified 

 cholesterol in serum was determined by a cholesterol oxidase assay 

 system which is both highly snesitive and specific. 



For tissue-free amino acid analysis, muscle tissue was thawed, 

 weighed and homogenized in distilled water using a 2/1 ratio of distilled 

 water/wet weight. Homogenates were deproteinized with 12.5% trichloro- 

 acetic acid and then centrifuged. The supernates were frozen, thawed, 

 and centrifuged again to remove additional TCA precipitates. The super- 

 nates were then evaporated to dryness on a rotary evaporator and the 

 residue dissolved in 0.2 M Citrate buffer adjusted to pH 2.2. The 

 extracts were analyzed with a Beckman automatic amino acid analyzer. 

 The amino acid composition of the extract and the concentration of 

 individual amino acids in it were determined. Taurine/glycine molar 

 ratios were computed. Variations in amino acid compositions and concen- 

 trations among fish and oysters from different sampling stations were 

 analyzed statistically. 



Plaice liver was analyzed for ascorbic acid. Tissue samples were 

 thawed, weighed and homogenized in 3% metaphosphoric acid-8% acetic acid 

 solution. After centrifugation, the supernates were analyzed immediately 

 by the a,a-diperidyl technique of Zannoni et al. (1974). 



Oysters and plaice samples for hydrocarbon analysis were taken at 

 the same times and places as samples for biochemical/histopathological 

 analysis. Ten to twelve whole oysters were pooled for each sample. 

 They were shucked and tissues were rinsed in distilled water, blotted 

 dry, wrapped in hexane-cleaned aluminum foil and frozen at -60°C until 

 analysis. For the April 1979 sample, whole fish were used. For sub- 

 sequent samples, pooled samples of liver and muscle from 5-10 fish were 

 used. Fish tissue samples were handled like oyster samples. 



Hydrocarbon analyses were performed by Dr. Paul Boehm, ERCO, 

 Cambridge, Massachusetts using capillary gas chromatography /mass 

 spectrometry. 



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