title: The effect of chronic saline exposure on the electrolyte balance, nitrogen metabolism, and corticosterone titer in the American alligator, Alligator mississippiensis.
abstract: Juvenile alligators were exposed to fresh water, 5, 10, 15 and 20% sea-water for 4 weeks. Hematocrit, plasma corticosterone, plasma and urine osmolality, [Na+], [K+], [Cl-] and uric acid were measured at weekly intervals. Although no change was found in plasma NaCl at 5%, a significant increase in NaCl Urine/Plasma (U/P) ratio was found; however, no further increase in NaCl U/P ratio was found at higher salinities, and plasma NaCl increased with salinity. Plasma corticosterone increased significantly at 10% and greater, and a dramatic increase in plasma and urine uric acid was also found at these salinities. At 10% and greater, alligators ceased feeding and lost up to 27% of their initial body weight. Mortalities occurred during weeks 3 and 4, at 15 and 20%. A possible role for corticosterone in increasing the NaCl U/P ratio is discussed. It is concluded that juvenile alligators are unable to survive chronic exposure to hyperosmotic salinities.
authors.forename: D J
authors.initials: DJ
authors.lastname: Laurén
mesh_terms: D000489:Alligators and Crocodiles / Q000378:metabolism*; D000818:Animals; D003345:Corticosterone / Q000378:metabolism*; D004573:Electrolytes / Q000378:metabolism; D005618:Fresh Water; D006400:Hematocrit; D007700:Kinetics; D009584:Nitrogen / Q000378:metabolism*; D009994:Osmolar Concentration; D012104:Reptiles / Q000378:metabolism*; D012623:Seawater; D012965:Sodium Chloride / Q000494:pharmacology*; D014527:Uric Acid / Q000378:metabolism; D014882:Water-Electrolyte Balance / Q000187:drug effects*
chemical_list: D004573:Electrolytes; D014527:Uric Acid; D012965:Sodium Chloride; D009584:Nitrogen; D003345:Corticosterone