@article {4158,
	title = {Bioaccumulation and clearance of microcystins from salt water, mussels, Mytilus edulis, and in vivo evidence for covalently bound microcystins in mussel tissues},
	journal = {Toxicon},
	volume = {35},
	number = {11},
	year = {1997},
	note = {ISI Document Delivery No.: YM145Times Cited: 73Cited Reference Count: 48},
	month = {Nov},
	pages = {1617-1625},
	type = {Article},
	abstract = {Over a period of 3 days saltwater mussels, Mytilus edulis, were fed a cyanobacteria, Microcystis aeruginosa, that contained a high concentration of microcystins, The mussels were killed on a periodic basis over the course of 2 months, Mussels were also collected at two sites were high levels of microcystins in tissues had been noted. A strategy based on the chemically unique nature of the C-20 beta-amino acid, (2S,3S,8S,9S)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoi c acid (Adda), portion of the microcystins was used in conjunction with a protein phosphatase (PPase) assay to analyse for both covalently bound microcystins and free microcystins in the mussel tissues, The mussel PPase assay results were compared with the Lemieux oxidation gas chromatography-mass spectrometry (GCMS) analysis. Less than 0.1\% of the total microcystin burden in the mussel tissue was found to be extractable with MeOH. Thus, direct evidence was provided for the existence of covalently bound microcystins in mussel tissues in vivo. The mussels rapidly cleared the covalently bound microcystins when transferred to untreated seawater. Within 4 days the total microcystin burden dropped from a high of 336.9 (+/- 45.8) mu g/g wet tissue to 11.3 (+/- 2.6) mu g/g. After 4 days postexposure until completion of the experiment the total levels remained below the detection limits of the GCMS method, The levels of free microcystins, extracted with MeOH and detected by the PPase assay, fell from 204 ng/g wet tissue to a residual 14 ng/g over a 53 day postexposure period. Presumably the bound microcystin present in the mussel tissue exists as a covalent complex with the PP-1 and PP-2A enzymes. We conclude that in any shellfish monitoring program it is the total tissue microcystin burden that needs to be considered. (C) 1997 Elsevier Science Ltd.},
	keywords = {AERUGINOSA, BLUE-GREEN-ALGAE, cyanobacteria, DIARRHETIC SHELLFISH TOXINS, IDENTIFICATION, LR, OKADAIC ACID, PEPTIDE TOXIN, PROTEIN PHOSPHATASE INHIBITORS, TUMOR PROMOTION},
	isbn = {0041-0101},
	url = {<Go to ISI>://000071033700005},
	author = {Williams, D. E. and Dawe, S. C. and Kent, M. L. and Andersen, R. J. and Craig, M. and Holmes, C. F. B.}
}
@article {4157,
	title = {Evidence for a covalently bound form of microcystin-LR in salmon liver and dungeness crab larvae},
	journal = {Chemical Research in Toxicology},
	volume = {10},
	number = {4},
	year = {1997},
	note = {ISI Document Delivery No.: WU385Times Cited: 56Cited Reference Count: 55},
	month = {Apr},
	pages = {463-469},
	type = {Article},
	abstract = {The chemically unique nature of the C-20 beta-amino acid (2S,3S,8S,9S)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoi c acid (Adda) portion of the microcystins has been exploited to develop a strategy to analyze for the total microcystin-1R (1; see Figure 1) burden in salmon liver and crab larvae tissues. Lemieux oxidation of microcystin-LR (1) gives 2-methyl-3-methoxy-4-phenylbutanoic acid (2), a unique marker for the presence of microcystins. The butanoic acid 2 can be isolated and detected by GC/MS from the livers of Atlantic salmon that received an ip injection of microcystin-1R (1) and from tissues of wild-caught crab larvae. The Lemieux oxidation-GC/MS results are compared with those from MeOH extraction-PPase analysis. Only similar to 24\% of the total microcystin-1R (1) burden in salmon liver tissue is found to be extractable with MeOH. Similarly, the Lemieux oxidation-GC/MS method detected 10 000-fold greater microcystin concentrations in Cypress Island Dungeness crab larvae than did the MeOH extraction-PPase method. The disparity in microcystin concentrations measured by the two methods is taken as direct evidence for the existence of covalently bound microcystins in vivo.},
	keywords = {BLUE-GREEN-ALGAE, CYCLIC, DIARRHETIC SHELLFISH TOXINS, DIHYDROMICROCYSTIN-LR, HEPATOCELLULAR, OKADAIC ACID, PEPTIDE TOXIN, PROTEIN PHOSPHATASE INHIBITORS, RAT-LIVER, TISSUE DISTRIBUTION, TUMOR PROMOTION, UPTAKE},
	isbn = {0893-228X},
	url = {<Go to ISI>://A1997WU38500017},
	author = {Williams, D. E. and Craig, M. and Dawe, S. C. and Kent, M. L. and Holmes, C. F. B. and Andersen, R. J.}
}
