Acid phosphatase activity of chondroclasts from Fusarium-induced tibial dyschondroplastic cartilage

Tibial dyschondroplasia was induced in broiler chickens by oral administration of fusarochromanone, the toxic component of Fusarium equiseti. In two experiments, the activity of acid phosphatase in chondroclasts was assessed histochemically. Chicks were examined at 7, 14, 21, and 28 days of treatment in Expt. 1 and at 2, 4, and 6 days of treatment in Expt. 2. The staining for acid phosphatase was consistently lower in fusarochromanone-treated chicks after 2 days of treatment than in age-matched controls, and the onset of this difference corresponded to the onset of lesions. However, the decrease in acid phosphatase staining intensity was significant only at day 21 in Expt. 1 and at day 6 in Expt. 2. The deficiency of acid phosphatase in chondroclasts was judged to be of insufficient magnitude to account for the accumulation of growth plate cartilage that characterizes tibial dyschondroplasia.