Alveolar bone dynamics in osteoporotic rats treated with raloxifene or alendronate: confocal microscopy analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Raloxifene on Periapical Lesions in Ovariectomized Rats

Introduction: The aim of this study was to evaluate the effect of raloxifene (RLX) during progression of periapical lesions in ovariectomized (OVX) rats. Methods: Female Wistar rats were OVX or subjected to sham surgery and received vehicle or MX by gavage for 90 days. The treatment groups were as follows: sham surgery and treated with vehicle (SHAM-veh), OVX and treated with vehicle (OVX-veh), and OVX and treated with RLX (OVX-RLX). During treatment, the pulp of lower first molar was exposed to the oral. environment for induction of periapical lesion that was analyzed 7 or 30 days aftdr procedure. Blood samples were taken from jugular vein for measurement of estradiol, and the mandibles were removed and prepared for radiographic, histopathologic, histometric, and immunohistochemical analysis. Results: Estradiol plasma concentration showed hypoestrogenism in OVX rats. The histopathologic analysis of the OVX/RLX group was similar to that of the SHAM-veh group, whereas OVX-veh group showed larger penapical lesions with more intense inflammatory response and more cells positive for tartrate-resistant acid phosphatase. Radiographically, the groups were similar, but lesions on day 7 were smaller than lesions on day 30. Conclusions: The results suggest that hypoestrogenism potentiates the progression of periapical lesions, and such condition was reversed by treatment with RLX.

Immunolocalization of markers for bone formation during guided bone regeneration in osteopenic rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of different periods of estrogen replacement onset in the tibia of ovariectomized rats

Background and aims Estrogen deficiency results in increased bone turnover and can lead to osteoporosis. Hormone replacement therapy (HRT) seems to be the most effective means of reducing bone loss and fractures. However, the effects of the period of HRT onset on bone tissue require further elucidation. This study aimed to evaluate the effects of different periods of HRT onset on the trabecular bone of ovariectomized rats.Methods Seventy-five ovariectomized Wistar rats were divided into five groups according to the onset of treatment. Each group was subdivided into experimental (E; n = 10) and control (C; n = 5), according to treatment with 17-beta-estradiol or vehicle alone (soybean oil), respectively, administered subcutaneously. The first group received treatment immediately post-surgery, while treatment in the remaining groups was initiated 1, 2, 3 and 4 weeks post-surgery. Euthanasia occurred at 9 weeks post-surgery. The left tibias were removed and prepared for histomorphometric analyses. The histomorphometric results were statistically analyzed by the Student's t test (p < 0.05).Results The percentage of trabecular bone was significantly greater in the first (p = 0.002) and second (p = 0.039) experimental subgroups compared with the control for the same period. In the experimental subgroups, the percentage of trabecular bone decreased according to the delay in HRT onset and was statistically significant (t = 3.367; p = 0.0023).Conclusion These findings indicate an increase in trabecular bone loss in tibia at 9 weeks post-ovariectomy. The period of HRT/E onset is important for preventing bone loss; however, despite its preventive effects, HRT/E does not restore lost bone.

Laparoscopy of the genitourinary tract of small ruminants

Laparoscopic endosurgery is an important tool for small ruminant breeding especially due to its wide versatility, both in reproductive biotechnologies and therapeutic approach. The purpose of this review is to present the applicability and advantages of endosurgery for routine use in small ruminants. Several endosurgical techniques of the genitourinary tract of small ruminants, including artificial insemination, embryo transfer, and oocyte retrieval for IVF, ovariectomy, cystotomy and renal biopsy are approached. The endoscopic techniques can improve the development of potential zootechnical indexes on the short-term period in comparison to traditional approaches.

Influência da inalação da fumaça de cigarro no reparo de enxertos ósseos autógenos onlay em ratas ovarectomizadas: estudo histomorfométrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Raloxifene modulates regulators of osteoclastogenesis and angiogenesis in an oestrogen deficiency periapical lesion model

Aim To analyse the local regulatory mechanisms of osteoclastogenesis and angiogenesis during the progression of periapical lesions in female rats with oestrogen deficiency and treatment with raloxifene (RLX). Methodology Female Wistar rats were distributed into groups: SHAM-veh, subjected to sham surgery and treated with a vehicle; OVX-veh, subjected to ovary removal and treated with a vehicle; and OVX-RLX, subjected to ovary removal and treated with RLX. Vehicle or RLX was administered orally for 90 days. During treatment, the dental pulp of mandibular first molars was exposed to the oral environment for induction of periapical lesions, which were analysed after 7 and 30 days. After the experimental periods, blood samples were collected for measurement of oestradiol, calcium, phosphorus and alkaline phosphatase. The rats were euthanized and the mandibles removed and processed for immunohistochemical detection of receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), hypoxia-inducible factor-1 alpha (HIF-1α) and bone-specific alkaline phosphatase (BALP). Data were compared using Kruskal–Wallis followed by Dunn test (nonparametric values) and anova followed by the Tukey's test (parametric values). Results The plasma concentration of oestradiol showed hypo-oestrogenism in the rats subjected to ovary removal. On day 7, alkaline phosphatase activity, calcium and phosphorus were higher in the OVX-RLX group than in the OVX-veh group (P < 0.001), but immunolabelling for RANKL and HIF-1α was lower in OVX-RLX group (P < 0.001). On day 30, the OVX-veh group had higher immunolabelling for RANKL than the OVX-RLX group (P < 0.05). There were no significant differences in the immunoreactivity of OPG and BALP between any groups at either time-point (P > 0.05). Conclusion RLX therapy reversed the increased levels of the local regulators of both osteoclastogenesis and angiogenesis induced by oestrogen deficiency.

Influência da inalação da fumaça de cigarro na regeneração óssea guiada em enxertos autógenos onlay em ratas com deficiência estrogênica: estudo histomorfométrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)