Implications of combined ovariectomy and glucocorticoid (dexamethasone) treatment on mineral, microarchitectural, biomechanical and matrix properties of rat bone

Summary Osteoporosis is one of the deleterious side effects of long‐term glucocorticoid therapy. Since the condition is particularly aggressive in postmenopausal women who are on steroid therapy, in this study we have attempted to analyse the combined effect of glucocorticoid (dexamethasone) treatment and cessation of oestrogen on rat bone. The dual aim was to generate osteoporotic bone status in a short time scale and to characterise the combination of glucocorticoid–postmenopausal osteoporotic conditions. Sprague Dawley rats (N = 42) were grouped randomly into three groups: untreated control, sham‐operated and ovariectomized–steroid (OVX‐Steroid) rats. Control animals were euthanized with no treatment [Month 0 (M0)], while sham and OVX‐Steroid rats were monitored up to 1 month (M1) and 3 months (M3) post laparotomy/post OVX‐Steroid treatment. Histology, dual‐energy X‐ray absorptiometry (DXA), micro‐computed tomography (micro‐CT), and biomechanical and mRNA expression analysis of collagenous, non‐collagenous matrix proteins and osteoclast markers were examined. The study indicated enhanced osteoclastogenesis and significantly lower bone mineral density (BMD) in the OVX‐Steroid rats with Z‐scores below −2.5, reduced torsional strength, reduced bone volume (BV/TV%), significantly enhanced trabecular separation (Tb.S), and less trabecular number (Tb.N) compared with sham rats. Osteoclast markers, cathepsin K and MMP 9 were upregulated along wit...
Source: International Journal of Experimental Pathology - Category: Pathology Authors: Tags: Original Article Source Type: research