Osteoporosis is a complex systemic disease, which affects nearly half of the women over 50 years and leads to approximately 9 million bone fractures worldwide. The guidelines of the US FDA (Food and Drug Administration) require that antiosteoporotic drugs need to be tested as well on rodents as on large animals. Those large animal models should mimic the phenotype of postmenopausal women with osteoporosis as good as possible. At the moment young minipigs and sheep are mainly used in osteoporosis research. Our aim was to investigate adult conventional sows for their suitability in osteoporosis research. We expected a higher analogy between aging women and adult, multiparous sows. 32 female, multiparous large white sows with an average age of 33,5 ± 9,5 months were divided in 4 different groups: group (I) OVX, 0,75 % Ca2+, group (II) OVX, 0,3 % Ca2+, group (III) Sham-OVX, 0,75 % Ca2+ and group (IV) OVX, 0,3 % Ca2+. The total period of examination was 10 months and every 2 months blood samples were taken to analyze biochemical bone markers as well as hematologic and immunologic parameters. After this period all sows were slaughtered in order to extract tibia, radius and lumbar vertebra for µCT measurements, DEXA-scans and ashing. The analysis of bone markers, cytokines, hematology and leukocytes subpopulations represent undulating results without noticeable changes by calcium restriction or ovariectomy between groups or within groups as well.
The morphological investigation of the bones did not point out any differences between the groups. As a result, multiparous, conventional OVX and calcium-deprived sows do not seem to be suitable as proper experimental animals for osteoporosis research. However, it might be interesting to use them for analyzing those factors, which prevent them to lose bone despite OVX and calcium restriction.