Origin of serum alkaline phosphatase in the dog.

The origin of canine serum alkaline phosphatase (ALP) was investigated by various means. On the basis of electrophoretic migration, neuraminidase treatment, thermal denaturation, and chromatographic fractionation, canine serum was found to contain ALP principally of hepatic origin. There was evidence of only a minor portion of ALP being of osseous origin. Intestinal ALP was not detected in canine serum when monitored by immunochemical technique, L-phenylalanine inhibition, and thermal denaturation.