Enzyme histochemical studies of induced heterotopic cartilage and bone formation in guinea pigs with special reference to acid phosphatase

Abstract

Abstract— Heterotopic bone and cartilage formation was studied in a bone induction model in abdominal muscles of guinea pigs using demineralised allogenic dentin as inductive material. The light microscopic study showed high activity of acid phosphatase (AcP) and leucine aminopeptidase (LAP) in young matrix‐producing cells. The highest activity was seen in cells surrounded by unmineralized matrix. In the surrounding matrix there was strong staining of AcP, especially in matrix with high glycosaminoglycan content. Electron microscopic studies of AcP in sections from unfixed frozen tissue showed intracellular activity mainly located in lysosomes. Extracellular AcP activity was found in matrix vesicles in the newly formed hard tissue. It was most pronounced in areas of cartilaginous differentiation. By means of energy dispersive X‐ray microanalysis in a scanning transmission electron microscope, the deposits were confirmed to contain, lead precipitates. With the exception of some lysosomal staining, prefixation with formaldehyde prevented demonstration of the enzyme activity. Both AcP and LAP may be involved in degradation of organic components of the matrix which enable the matrix to mineralize.

Enzyme histochemical studies of acid phosphatase isoenzymes in induced heterotopic bone formation in guinea pigs

“…AcP activity was also found in osteoid osteocytes of rat by WERGEDAL & BAYLING (18) while HAMMARSTROM & HASSELGREN (9) did not demonstrate AcP actiidty in the osteoid of man and monkey. Forthcoming results from enzyme electron microscopic studies on the present model bave revealed AcP activity in lysosomes and also in the endoplasmic reticulum of tbe tnatrix-producing ceils (16).…”

Capacitive interdigitated system of high osteoinductive/conductive performance for personalized acting-sensing implants

“…4c ). Also upregulated was NPEPL1 , a predicted aminopeptidase, which is a group of enzymes upregulated during osteodifferentiation and believed to degrade matrix organic components to enable mineralization 74 , 75 . TTYH3 , a Ca 2+ -activated chloride channel expressed in excitable tissues and whose gene deletion was clinically associated with low bone mineralization 76 , 77 , was also UReg.…”

Reactive osteocartilaginous metaplasia in denture wearers: a rare trauma‐related lesion

“…In our case, the osteocartilaginous metaplasia may be related to a possible combination of local and systemic contributing factors. The denture mechanical stimulation, diabetic history predisposing to inflammation and the presence of root fragments in the region may all play a role in the pathogenesis of this particular case; heterotopic bone and cartilage formation induced by implants of mineralised hard tissues have been showed in experimental studies.…”