title: Evaluation of circulating eosinophil count and adrenal gland function in California sea lions naturally exposed to domoic acid.
abstract: OBJECTIVE
  To determine the effect of natural exposure to domoic acid (DA) on eosinophil counts and adrenal gland function in California sea lions (Zalophus californianus).
  
  
  METHODS
  Cross-sectional prospective study.
  
  
  METHODS
  39 California sea lions.
  
  
  METHODS
  Adult female sea lions admitted to a rehabilitation hospital during 2009 were classified into 1 of 3 groups (acute DA toxicosis, chronic DA toxicosis, or no DA exposure) on the basis of clinical signs, DA concentration in urine or feces, and hippocampal morphology. Endoparasite burden, eosinophil count, and serum cortisol and plasma ACTH concentrations were determined for each sea lion. For a subset of 8 sea lions, fecal glucocorticoid concentration after IM administration of cosyntropin was determined.
  
  
  RESULTS
  Sea lions exposed to DA (acute DA toxicosis, n = 11; chronic DA toxicosis, 19) had higher eosinophil counts and lower serum cortisol concentrations, compared with values for sea lions with no DA exposure (9). Eosinophil count was not associated with endoparasite burden. Serum cortisol concentration was associated with plasma ACTH concentrations in sea lions from the no DA exposure group but not in sea lions in the acute or chronic DA toxicosis groups. Following cosyntropin injection, fecal glucocorticoid concentrations increased in all sea lions evaluated except 1.
  
  
  CONCLUSIONS
  In adult sea lions, eosinophilia may be a cost-effective biomarker for DA exposure and may reflect alterations in hypothalamic, pituitary gland, or adrenal gland function. Domoic acid exposure may have subtle health effects on marine animals in addition to induction of neurologic signs.
authors.affiliation: The Marine Mammal Center, Sausalito, CA 94965, USA. gullandf@tmmc.org
authors.forename: Frances M D
authors.initials: FM
authors.lastname: Gulland
authors.forename: Ailsa J
authors.initials: AJ
authors.lastname: Hall
authors.forename: Denise J
authors.initials: DJ
authors.lastname: Greig
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Frame
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Colegrove
authors.forename: Rebecca K N
authors.initials: RK
authors.lastname: Booth
authors.forename: Sam K
authors.initials: SK
authors.lastname: Wasser
authors.forename: J Catharine R
authors.initials: JC
authors.lastname: Scott-Moncrieff
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects*; D000818:Animals; D003430:Cross-Sectional Studies; D004804:Eosinophils / Q000378:metabolism*; D005260:Female; D007608:Kainic Acid / Q000031:analogs & derivatives* / Q000633:toxicity; D008387:Marine Toxins / Q000633:toxicity; D009467:Neuromuscular Depolarizing Agents / Q000633:toxicity*; D046070:Sea Lions / Q000097:blood*
chemical_list: D008387:Marine Toxins; D009467:Neuromuscular Depolarizing Agents; C012301:domoic acid; D007608:Kainic Acid