Aminobisphosphonates cause changes in the thickness of the different zones of the epiphyseal disk of Wistar rats

Abstract

(1) Objective: The aim of the present study was to test the hypothesis that Alendronate Sodium (AS) and Zoledronic Acid (ZA) modifies the thickness of the different zones of the epiphyseal disc of the femur of rats. (2) Materials and methods: Wistar rats (n = 19) were divided into three groups: Group 01: sodium alendronate oral (3 mg / kg / day); Group 02: zoledronic acid, intraperitoneal route (0.2 mg / kg / week) and Group 03: control, without drug administration. After 21 days of treatment, the animals were euthanized and the femurs were collected for subsequent preparation of stained slides with Hematoxylin and Eosin. The images of the epiphyseal disk region were captured using Qcapture® software with a 400-fold increase. The areas analysis was performed with the Adobe Photoshop CS3 extended program (3) Results: AS caused reduction in the proliferative zone, while ZA caused significant decrease in most areas with cellular activity and a significant increase in the calcified zone. The total thickness of the growth plate is not caused by proportional reduction of all the zones that integrate the epiphyseal disk, because they responded differently. (4) Conclusions: These medications caused changes in the thickness of the different zones on the femoral epiphyseal disk, showing that AS and ZA may interfere with the normal growth of the long bones.