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Ovariectomy‐associated changes in bone mineral density and bone marrow haematopoiesis in rats
Author(s) -
Lei Zhu,
Xiaoying Zhao,
Xingguo Lu
Publication year - 2009
Publication title -
international journal of experimental pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.671
H-Index - 72
eISSN - 1365-2613
pISSN - 0959-9673
DOI - 10.1111/j.1365-2613.2009.00661.x
Subject(s) - ovariectomized rat , bone mineral , bone marrow , medicine , femur , endocrinology , adipose tissue , cancellous bone , osteoporosis , bone tissue , haematopoiesis , bone density , chemistry , anatomy , stem cell , biology , surgery , estrogen , genetics
Summary The relationship between the bone mass loss and bone marrow haematopoiesis in osteoporosis remains obscure. We selected 3‐month‐old female Sprague–Dawley rats and randomly divided them into six groups. Three groups were ovariectomized (OVX), while the other three groups were sham operated (Sham). Four, 8 and 12 weeks after the surgical procedure, the rats were euthanized and sampled. The left femur was used for measurement of bone mineral density (BMD). The right femur distal metaphysic cancellous bone was processed for morphological evaluation. Our results showed that the femur BMD in the 4‐week OVX group was not significantly decreased compared with that of the 4‐week Sham group, but that the volume of adipose tissue in the bone marrow was markedly increased. The femur BMD in the 8‐week OVX group was decreased significantly compared with that of the 8‐week Sham group ( P < 0.05). Meanwhile, the volume of haematopoietic tissue decreased and the volume of adipose tissue increased. The number of megakaryocytes was decreased ( P < 0.05). Interestingly, the osteoclasts and mast cells were increased in number in the 8‐week OVX group ( P < 0.05). These changes became obvious in the 12‐week OVX rats, in contrast to the Sham groups. The volume of trabecular bone and the number of osteoblasts in the 12‐week OVX group decreased significantly. Increased reticulin fibres were observed only in the 12‐week OVX group. Our studies demonstrated a reciprocal correlation between bone‐forming osteoblasts and marrow adipose tissue and suggest that OVX rats may be valuable as an animal model to study hypohaemopoiesis.