Alkaline Phosphatase Reaction in Hair Follicles of Male Beagle Dogs During Hair Cycle Stages

This study investigated alkaline phosphatase activity in hair follicles during different hair cycle stages in 9 male Beagle dogs of varying ages over a year. Skin biopsies were taken monthly, and alkaline phosphatase activity was assessed using Gomori's calcium cobalt method. The study found that during the anagen stage, the dermal papilla showed a weak or negative reaction to alkaline phosphatase, which was unexpected. In contrast, a positive reaction was observed during the catagen stage, and a strong positive reaction was noted in the telogen stage. The alkaline phosphatase activity was present throughout the dermal papilla, not just in the blood vessels, during both early and late stages.