title: Effect of environmental salinity manipulation on uptake rates and distribution patterns of waterborne amino acids in the Pacific hagfish.
abstract: Among vertebrates, hagfish are the only known iono- and osmoconformers, and the only species thus far documented to absorb amino acids directly across the skin. In the current study, short-term (6h) manipulations of exposure salinities (75-125% seawater) were conducted to determine whether changes in osmotic demands influenced the uptake and tissue distribution of waterborne amino acids (alanine, glycine and phenylalanine), in the Pacific hagfish, Eptatretus stoutii. No changes in erythrocyte or muscle amino acid accumulation rates were noted, but the patterns of plasma amino acid accumulation were suggestive of regulation. Contrary to expectations, glycine transport across the skin in vitro was enhanced in the lowest exposure salinity, but no other salinity-dependent changes were demonstrated. Overall, this study indicates that uptake and distribution of amino acids varies with salinity, but not in a manner that is consistent with a role for the studied amino acids in maintaining osmotic balance in hagfish.
authors.affiliation: Athabasca River Basin Research Institute and Faculty of Science and Technology, Athabasca University, Athabasca, Alberta T9S 3A3, Canada; Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada; Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada. Electronic address: cglover@athabascau.ca.
authors.forename: Chris N
authors.initials: CN
authors.lastname: Glover
authors.affiliation: Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada; Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada.
authors.forename: Tamzin A
authors.initials: TA
authors.lastname: Blewett
authors.affiliation: Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada; Department of Biology, McMaster University, Hamilton, Ontario L8S 4K1, Canada; Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
authors.forename: Chris M
authors.initials: CM
authors.lastname: Wood
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D006196:Hagfishes / Q000378:metabolism*; D054712:Salinity; D012623:Seawater
chemical_list: D000596:Amino Acids
keywords: Amino acid; Cell volume regulation; Dissolved organic carbon; Hagfish; Nutrition; Osmoconformer; Osmolyte; Osmoregulation; Salinity