Serum chemistry of free-ranging white whales (Delphinapterus leucas) in Svalbard

BACKGROUND: Abnormal physiological conditions and diseases can change the concentrations of enzymes, metabolites, and minerals in the body. Serum chemistry information may thus be indicative of a specific disease; interpretation of such information requires knowledge of serum chemistry reference intervals from a seemingly healthy population of the species. OBJECTIVE: The aim of this study was to obtain serum chemistry reference intervals for a population of white whales. METHODS: Blood samples were collected from 21 free-ranging white whales (beluga; Delphinapterus leucas). The whales were live-captured in nets during 1996-2001 in Storfjorden, Van Mijenfjorden, and Van Keulenfjorden (Svalbard, Norway). While the whales were briefly physically restrained, blood was collected from the caudal vein into vacuum tubes without anticoagulant. The blood was left to clot for 4-6 hours before serum was obtained by centrifugation. The serum samples were then kept at -20 degrees C until analysis. Enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase ALP], creatine kinase, lactate dehydrogenase LDH], amylase, lipase), metabolites (urea, creatinine, bilirubin, cholesterol, triglycerides, nonesterified fatty acids, glucose), and minerals (calcium, phosphate, magnesium, sodium, potassium, chloride) were analyzed in an Advia 1650 System (Bayer, Tarrytown, NY, USA). Cortisol was analyzed in an Immulite One system (Diagnostic Products Corporation, Los Angeles, CA, USA). The major blood proteins (albumin and globulins) were separated by gel electrophoresis in a Beckman Paragon electrophoresis system (Beckman Coulter, Inc., Fullerton, CA, USA). RESULTS: Serum values for all analytes were reported as median and range, and reference intervals were calculated as 10-90th percentiles. Activities of ALP and LDH and cortisol concentration were higher, and protein and bilirubin concentrations were lower compared with those previously reported for white whales from Canada; remaining results were strikingly similar in these 2 white whale populations. CONCLUSIONS: These data provide valuable serum chemistry reference intervals for future health assessments of white whales in Svalbard and other white whale populations, as well as captive individuals.