HISTOCHEMICAL AND HISTO-ENZYMOLOGICAL INVESTIGATIONS OF GROWING CARTILAGE IN PSEUDOHYPOPARATHYROIDISM

Abstract

ABSTRACT A biopsy specimen of the tibial growing cartilage in a patient with pseudohypoparathyroidism aged 9 was studied. The cartilage was found to be narrow with a relatively wide resting zone, short columns of cells and very long directory lines. No osteoclasts were found. Histochemical investigations disclosed the presence of glycogen and of metachromatic, alcianophilic and Hale positive material within the chondrocytes. The matrix of the resting and proliferative zones contained Hale, γ-metachromatic and alcianophilic and weakly PAS positive material. Metachromasia was reversed by hyaluronidase and trypsin and partially extracted by sialidase. In the lower hypertrophic zone the matrix was orthochromatic, PAS positive and strongly alcianophilic. The directory lines were orthochromatic. Sialidase had no effect and hyaluronidase only partially reversed the alcianophilic material. By means of the cytoenzymological study strong lactate and glutamate dehydrogenase activity was detected; moderate activity of succinate dehydrogenase, ATP-ase and 5-nucleotidase; low activity of glutamyltranspeptidase, nonspecific esterase, acid phosphatase and glucose-6-phosphatase; lack of activity of NADP dependent isocitrate dehydrogenase, β-glucuronidase, leucyl-aminopeptidase, cysteine desulphurase. The alkaline phosphatase activity was detected in the hypertrophic chondrocytes and in the osteoblasts.