Experimental tetracycline labeling in avian osteopetrosis.

Osteopetrosis was experimentally produced and lesion development in time was studied by fluorescent illumination of tetracycline labels in the bone. Bones from birds 84, 115, 186 and 354 days of age were examined by ground section under ultraviolet light. Periosteal activity of the tibia and femur was present in normal bones at 84 days of age but had stopped at 115 days. Focal periosteal activity of osteopetrotic lesions was present at 186 days but not at 354 days of age. Slight endosteal activity of osteopetrotic bones was present at 354 days of age. Osteopetrotic bone formed at a rate of 1.26 mm. per week or 6 times faster than normal bone in some of these lesions. Tetracycline diffused throughout the 354-day-old osteopetrotic lesion but not normal compact bone indicating that the osteopetrotic bone is porous and spongy.