The laboratory rat as an animal model for osteoporosis research.

TLDR

Osteoporosis, a multifactorial systemic disorder predominantly affecting Caucasian women, is commonly studied using animal models, with the laboratory rat being the most widely preferred species due to its extensively characterized skeleton and manageable limitations. This review aims to describe the ovariectomized rat as an effective osteoporosis model and to guide selection of age and bone sites for specific experimental objectives. The rat model induces bone loss through hormonal ablation, immobilization, or dietary changes, and its bone mass is assessed via biochemical markers, densitometry, histomorphometry, and mechanical testing.

Abstract

Osteoporosis is an important systemic disorder, affecting mainly Caucasian women, with a diverse and multifactorial etiology. A large variety of animal species, including rodents, rabbits, dogs, and primates, have been used as animal models in osteoporosis research. Among these, the laboratory rat is the preferred animal for most researchers. Its skeleton has been studied extensively, and although there are several limitations to its similarity to the human condition, these can be overcome through detailed knowledge of its specific traits or with certain techniques. The rat has been used in many experimental protocols leading to bone loss, including hormonal interventions (ovariectomy, orchidectomy, hypophysectomy, parathyroidectomy), immobilization, and dietary manipulations. The aim of the current review is not only to present the ovariectomized rat and its advantages as an appropriate model for the research of osteoporosis, but also to provide information about the most relevant age and bone site selection according to the goals of each experimental protocol. In addition, several methods of bone mass evaluation are assessed, such as biochemical markers, densitometry, histomorphometry, and bone mechanical testing, that are used for monitoring and evaluation of this animal model in preventive or therapeutic strategies for osteoporosis.