Análise histomorfométrica da artéria aorta de ratas submetidas à administração repetida da associação de etinilestradiol e gestodeno / Histomorphometric analysis of the aorta of rats submitted to repeated administration of association of ethinylestradiol and gestodene

Introdução: Os anticoncepcionais orais vêm sofrendo alterações em suas concentrações de estrogênio e progestogênio, baseando-se no fato de que doses mais baixas estão associadas a menor incidência de alterações metabólicas e de efeitos adversos, como o comprometimento da morfologia e função da artéria aorta. O objetivo deste estudo é avaliar a influência dos anticoncepcionais nas propriedades morfofuncionais da artéria aorta, através do método histoquímico, demonstrando sua utilidade nas análises histopatológicas. Métodos: Para tanto, foram utilizadas 15 ratas divididas em 3 grupos; Grupo controle (GC), cujos animais não receberam tratamento hormonal; Grupo 2 (G2), onde os animais receberam tratamento diário de 15 µg de etinilestradiol + 60 µg de gestodeno; e Grupo 3 (G3), que recebeu 30 µg de etinilestradiol + 75 µg de gestodeno. Após o tratamento, os animais foram eutanasiados e as artérias retiradas para análise histológica. Resultados: Os valores encontrados com a técnica de coloração histológica de hematoxilina e eosina (HE), bem como na coloração específica em histoquímica com Alcian Blue, demonstram que no G3, tratados com uma dosagem superior de hormônio, 8% das ratas tem aumento relevante da espessura de suas artérias, ou seja, superior ao G2, que recebeu dosagem menor de hormônio, e GC, o qual não recebeu nenhum tipo de tratamento. Conclusão: Este estudo demonstra que existem relações entre o espessamento das artérias, de ratas submetidas a dosagens de etinilestradiol e gestodeno, com a grande quantidade de mucopolissacarídeos depositados entre as túnicas das artérias. (AU)

Introduction: Pharmacological development of hormonal contraceptives has been undergoing changes in estrogen and progesterone doses, based on the fact that lower doses are associated with a lower incidence of metabolic changes and adverse effects, such as impairment of morphology and function of the aortic artery. The aim of this study is to evaluate the influence of contraceptives on the morphofunctional properties of the aortic artery, using the histochemical method, demonstrating its usefulness in histopathological analyzes. Methods: For this purpose, 15 rats were divided into 3 groups; Control group (GC), whose animals did not receive hormonal treatment; Group 2 (G2), where the animals received a daily treatment of 15 µg of ethinylestradiol + 60 µg of gestodene; and Group 3 (G3), whose animals received 30 µg of ethinylestradiol + 75 µg of gestodene. After treatment, the animals were sacrificed and the arteries removed for histologic analysis. Results: The values found, with HE measurements and Alcian Blue histochemical staining, showed that in G3, treated with a higher hormone dosage, there are 8% of the rats with a relevant increase in the thickness of their arteries, that is, higher than that of G2, which received lower dosage of hormone and that of GC, which received no treatment. Conclusion: This study demonstrates that there are relations between the thickening of the arteries of rats submitted to dosages of ethinylestradiol and gestodene with the great amount of mucopolysaccharides deposited between the tunics of the arteries. (AU)

A new heterologous fibrin sealant as scaffold to recombinant human bone morphogenetic protein-2 (rhBMP-2) and natural latex proteins for the repair of tibial bone defects.

Tissue engineering has special interest in bone tissue aiming at future medical applications Studies have focused on recombinant human bone morphogenetic protein-2 (rhBMP-2) and natural latex proteins due to the osteogenic properties of rhBMP-2 and the angiogenic characteristic of fraction 1 protein (P-1) extracted from the rubber tree Hevea brasiliensis. Furthermore, heterologous fibrin sealant (FS) has been shown as a promising alternative in regenerative therapies. The aim of this study was to evaluate these substances for the repair of bone defects in rats. A bone defect measuring 3mm in diameter was created in the proximal metaphysis of the left tibia of 60 rats and was implanted with rhBMP-2 or P-1 in combination with a new heterologous FS derived from snake venom. The animals were divided into six groups: control (unfilled bone defect), rhBMP-2 (defect filled with 5µg rhBMP-2), P-1 (defect filled with 5µg P-1), FS (defect filled with 8µg FS), FS/rhBMP-2 (defect filled with 8µg FS and 5µg rhBMP-2), FS/P-1 (defect filled with 8µg FS and 5µg P-1). The animals were sacrificed 2 and 6 weeks after surgery. The newly formed bone projected from the margins of the original bone and exhibited trabecular morphology and a disorganized arrangement of osteocyte lacunae. Immunohistochemical analysis showed intense expression of osteocalcin in all groups. Histometric analysis revealed a significant difference in all groups after 2 weeks (p<0.05), except for the rhBMP-2 and FS/rhBMP-2 groups (p>0.05). A statistically significant difference (p<0.05) was observed in all groups after 6 weeks in relation to the volume of newly formed bone in the surgical area. In conclusion, the new heterologous fibrin sealant was found to be biocompatible and the combination with rhBMP-2 showed the highest osteogenic and osteoconductive capacity for bone healing. These findings suggest a promising application of this combination in the regeneration surgery.

Use of a New Fibrin Sealant and Laser Irradiation in the Repair of Skull Defects in Rats

This study evaluated the osteogenic capacity of a new fibrin sealant (FS) combined with bone graft and laser irradiation in the bone repair. Defects were created in the skull of 30 rats and filled with autogenous graft and FS derived from snake venom. Immediately after implantation, low-power laser was applied on the surgical site. The animals were divided in: control group with autogenous graft (G1), autogenous graft and laser 5 J/cm2 (G2), autogenous graft and laser 7 J/cm2 (G3), autogenous graft and FS (G4), autogenous graft, FS and laser 5 J/cm2 (G5), autogenous graft, FS and laser 7 J/cm2 (G6). The animals were sacrificed 6 weeks after implant. Results showed absence of inflammatory infiltrate in the bone defect. New bone formation occurred in all groups, but it was most intense in G6. Thus, the FS and laser 7 J/cm2 showed osteoconductive capacity and can be an interesting resource to be applied in surgery of bone reconstruction.

Este estudo avaliou a capacidade osteogênica de um novo selante de fibrina (FS) associado com enxerto ósseo e irradiação laser no reparo ósseo. Defeitos foram criados no crânio de 30 ratos e preenchidos com enxerto autógeno e FS derivado do veneno de cobra. Imediatamente após implantação, foi aplicado laser de baixa potência na área cirúrgica. Os animais foram divididos em grupo controle com autógeno (G1), autógeno e laser 5 J/cm2 (G2), autógeno e laser 7J/cm2 (G3), autógeno e FS (G4), autógeno, FS e laser 5J/cm2 (G5), autógeno, FS e laser 7J/cm2 (G6). Os animais foram sacrificados 6 semanas após implante. Resultados mostraram ausência de infiltrado inflamatório no defeito ósseo. Neoformação óssea ocorreu em todos os grupos, entretanto, foi mais intenso em G6. Desta maneira, o FS e laser 7J/cm2 mostraram capacidade osteocondutiva e podem ser um interessante recurso a ser aplicado nas cirurgias de reconstrução óssea.