The serum activities of alkaline phosphatase isoenzymes measured using two approved methods in zoo-managed Asian elephants (Elephas maximus)

The approved Japanese measurement method of circulating alkaline phosphatase (ALP) has changed from that of the Japan Society of Clinical Chemistry (JSCC) to that of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). We measured the serum levels of total ALP (t-ALP) and those of the isoenzymes ALP2 and ALP3 in 50 Asian elephant (Elephas maximus) specimens using both methods. The activities determined by the IFCC method were roughly one-third lower than those determined by the JSCC method. We present conversion formulae. Our results enable comparisons of historical and current data on serum ALP activities in endangered, zoo-managed Asian elephants.