Influence of leukotrienes on intramembranous bone repair in middle-aged mice with induced ovarian failure

Abstract

Osteoporosis in women is a condition resulting from ovarian failure and consequent depletion of ovarian hormones. However, there is evidence that an increase in systemic inflammation contributes to its occurrence. Thus, the aim of the present study is to analyze alveolar bone repair and skeletal condition in 129SvEv WT female mice genetically modified (knockout) for 5-lipoxygenase (5LOKO) in surgically caused stropause (ovariectomy), under drug therapy with Montelukast (MTK). For this purpose, 72 female mice aged between 10 and 14 months will be used, 48WTs and 24 5LOKOs, divided into groups according to the treatments: WT- Control (no treatment), WT-MTK - MTK at a dose of 4mg/Kg , WT-OVX - submitted to ovariectomy (OVX), WT-OVX-MTK - submitted to OVX and medicated with MTK, 5LOKO - Control (no treatment), and 5LOKO-OVX - submitted to OVX. The animals in the OVX groups will undergo OVX 14 days before tooth extraction. The animals in the MTK groups will receive the first dose of medication one hour before the extraction of the upper right incisor, continuing every 24 hours until the periods of euthanasia, 7 and 21 days after extraction, when blood will be collected, jaws with the post-extraction sockets, mandibles, femurs and L5 vertebra of all animals. After centrifuging the blood, the plasma will be used for biochemical analysis of calcium, phosphorus, TRAP, alkaline phosphatase, total plasma antioxidant capacity and plasma lipid peroxidation. The jaws will be demineralized for analysis of the alveoli by HE stains, Goldner's trichrome and Picrosirius-red and immunohistochemistry for bone targets. The mandibles, femurs and vertebrae will be analyzed by means of computerized microtomography. The quantitative data will be submitted to statistical tests considering p<0.05.