Histological analysis of MPS VI rat femoral growth plates and articular cartilage.

<p>Representative images are shown for untreated MPS VI rats and each of the sc treatment groups (H & E staining, 20× magnification). (<b>A</b>) Growth plate analyses. Seven-month-old MPS VI rats revealed a complete loss of columnar arrangement in the knee growth plates as compared to normal animals. Overall, PPS sc treatment resulted in moderately improved chondrocyte orientation and growth plate organization, although significant vacuolated chondrocytes were still observed. <b>*</b>Indicates the growth plate. (<b>B</b>) Articular cartilage analyses. Micrographs revealed that sc PPS treatment reduced vacuole formation, suggesting reduced GAG storage in MPS VI articular chondrocytes, in a dose dependent manner. Weekly sc injections of 1 mg/kg had little to no effect, while improvements can be seen at 2 and 4 mg/kg.