Análises histoquímica e morfométrica de lesões endometrióticas induzidas em ratas e tratadas com dexametasona / Histochemical and morphometric analysis of endometriotic lesions induced in female rats and treated with dexamethasone

INTRODUÇÃO: A literatura relata que os implantes endometriais possuem receptores para hormônios esteroides, sendo estimulados principalmente pelo estrógeno, e que algumas estratégicas de tratamento têm sido propostas em modelos experimentais, tais como a utilização de glicocorticoides sintéticos, como a dexametasona. OBJETIVO: analisar histoquímica e morfometricamente lesões endometrióticas induzidas em ratas e tratadas com 0,8 mg/kg/dia de dexametasona. MATERIAL E MÉTODOS: Quarenta ratas albinas (linhagem Wistar) com 90 dias de vida, pesando aproximadamente 150 g, foram induzidas à endometriose e divididas em grupos: 1. ratas com endometriose e avaliadas após 34 dias (G1); 2. ratas com endometriose e avaliadas após 47 dias (G2); 3. ratas com endometriose e, após 21 dias do pós-operatório, tratadas com dexametasona por 13 dias (G3) e 4. ratas com endometriose e, após 21 dias do pós-operatório, tratadas com dexametasona por 13 dias e eutanasiadas após um período de 13 dias, contados a partir do término do tratamento com dexametasona (G4). Os fragmentos dos implantes endometriais foram fixados em Bouin, incluídos em paraplast e corados por hematoxilina-eosina e tricrômico de Mallory. As médias do número de glândulas foram submetidas ao teste não-paramétrico de Tukey-Kramer (p < 0,05). RESULTADOS: A dexametasona reduziu a inflamação nos implantes endometriais, o teor de colágeno no estroma e significativamente a área ocupada pelas glândulas (G1= 123,25 ± 6,44ª; G2= 113 ± 6,27ª; G3= 81,66 ± 3,05b; e G4= 94 ± 6,24b). CONCLUSÃO: A dexametasona, na dosagem utilizada, reduz os efeitos estrogênicos em implantes endometriais em ratas.

INTRODUCTION: The literature reports that endometrial implants have receptors for steroid hormones primarily stimulated by estrogen and that some treatment strategies have been proposed in experimental models such as the use of synthetic glucocorticoids, for example, dexamethasone. OBJECTIVE: to analyze histochemically and morphometrically endometriotic lesions induced in rats and treated with dexamethasone (0.8 mg/kg/day). MATERIAL AND METHODS: Forty albino female rats (Wistar strain), with 90 days of age, weighing approximately 150 g, were induced with endometriosis and divided into groups: I - rats with endometriosis and evaluated after 34 days, II - rats with endometriosis and evaluated after 47 days, III - rats with endometriosis and 21 days post-surgery treated with dexamethasone for 13 days and IV - rats with endometriosis and 21 days post-surgery treated with dexamethasone for 13 days and euthanized after a period of 13 days starting from the end of treatment. The fragments of endometrial implants were fixed in Bouin, embedded in Paraplast and stained with hematoxylin-eosin and Mallory trichrome. The mean number of glands was compared through nonparametric Tukey-Kramer test (p < 0,05). RESULTS: Dexamethasone reduced inflammation in the endometrial implants, the collagen content in the stroma and decreased significantly the area occupied by glands (GI - 123.25 ± 6.44ª; IGI - 113 ± 6.27ª; GIII - 81.66 ± 3.05b and GIV - 94 ± 6.24b). CONCLUSION: The applied dexamethasone dosage reduces estrogenic effects in endometrial implants in rats.

Effect of the treatment with dexamethasone, for 10 and 15 days, on the fertility in induced rats to polycystic ovaries, by constant illumination / Efecto del tratamiento con dexametasona, por 10 y 15 días, sobre la fertilidad en ratas inducidas a ovarios poliquísticos por la iluminación constante

The present study had the objective of obtaining information about fertility in rats treated with dexamethasone for 10 and 15 days consecutively, to polycystic ovaries, induced by constant illumination. It was used 40 albino rats (Rattus norvegicus albinus), aged 90 days, form the lineage Wistar, which were split, randomly, in four groups, each constituted of 10 animals, namely: Group I - rats kept in a clear/dark cycle for 12/12 hours, and after 100 days submitted to fertility evaluation (control); Group II - rats kept under constant illumination during 100 days and then submitted to fertility evaluation; Group III - rats kept under constant illumination during 100 days, then treated with dexamethasone for 10 days and submitted to fertility evaluation; Group IV - rats kept under constant illumination during 100 days, then treated with dexamethasone for 15 days and submitted to fertility evaluation. The results showed that the number of implanted sites was 38(G1), 37(G2), 32(G3) and 06(G4). The reduction in group IV was due to the high mortality during the experiment, probably because of the prolonged treatment with dexamethasone. These sites presented similar histological aspects. The macroscopic analysis of the neonates haven't shown any indication of malformation. Also, abortion haven't been observed. The treatment with dexamethasone for 10 days in rats does not affect the fertility and the development of the lungs, liver and kidneys of neonates, while the administration during 15 days leads to a high maternal mortality.

El estudio tuvo el objetivo de obtener informaciones sobre la fertilidad en ratas tratadas con dexametasona por 10 y 15 días seguidos, para ovarios poliquísticos, inducidos por iluminación constante. Se utilizó 40 ratas albinas (Rattus norvegicus albinus) con 90 días de edad, del linaje Wistar, las cuales fueron divididas, en cuatro grupos, cada uno constituido por 10 animales: Grupo I - ratas mantenidas en ciclo claro/oscuro de 12/12 horas, y después de 100 días sometidas a la evaluación de la fertilidad (control); Grupo II- ratas mantenidas bajo iluminación constante, durante 100 días, y luego sometidas a la evaluación de la fertilidad ; Grupo III - ratas mantenidas bajo iluminación constante, a lo largo de 100 días, y posteriormente tratadas con dexametasona por diez días, y sometidas a la evolución de la fertilidad; Grupo IV - ratas mantenidas bajo iluminación constante, durante 100 días, en seguida tratadas con dexametasona por 15 días, y sometidas a la evaluación de la fertilidad. Los resultados mostraron que el número de sitios implantados fue 38(GI), 37(G2), 32(G3), y 06(G4). La reducción en el grupo IV fue como consecuencia de la alta mortalidad durante la experiencia, probablemente en función del largo tratamiento con dexametasona. Esos sitios presentaron aspectos histológicos semejantes. El análisis macroscópico de los neonatos no mostró ningún vestigio de malformación. Tampoco fueron observados abortos. El tratamiento con dexametasona por 10 días en ratas, no afecta la fertilidad y el desarrollo de los pulmones, hígado y riñones de neonatos, mientras que la administración por 15 días lleva a una alta mortalidad materna.

Histological Evaluation of the Induced Endometriosis in Rats, after Treatment with Dexamethasone / Evaluación Histológica de la Endometriosis Inducida en Ratas, Posterior al Tratamiento con Dexametasona

The present research had the purpose to analyze morphologically the sites of endometrial implants on the external area of the musculature of the anterior abdominal wall of female rats, treated with dexamethasone. For so, these 15 albino female rats were used (Rattus norvegicus albinus), of the lineage Wistar with 90 days of age, that were submitted to the induction of the endometriosis, and divided in the following groups: Group I ­ induced female rats to endometriosis and evaluated after 21 days (control); Group II ­ induced female rats to endometriosis and after 21 days, treated with dexamethasone for 10 days; Group III - induced female rats to endometriosis, and after 21 days, treated with dexamethasone for 15 days. The dexamethasone was administered in the dosage of 0,8 mg/day/animal. Our results showed that the chronic inflammatory process in the endometriosis doesn't decrease after treatment with dexamethasone for 10 days, while the treatment with dexamethasone for 15 days reverted the chronic inflammatory process in the endometriosis, besides stimulating the proliferation of glands in endometrial implants.

El objetivo de la investigación fue analizar morfológicamente los sitios de implantes endometriales sobre la región externa de la musculatura de la pared abdominal anterior de ratones, tratados con dexametasona. Para ello, fueron utilizados 15 ratones albinos (Rattus norvergicus albinus), del linaje Wistar, de 90 días de edad, los cuales fueron sometidos a inducción de la endometriosis y divididos en los siguientes grupos: Grupo I ­ ratones inducidos a la endometriosis y evaluados tras 21 días (control); Grupo II ­ ratones inducidos a la endometriosis y tras 21 días, tratados con dexametasona durante 10 días; Grupo III ­ ratones inducidos a la endometriosis, y tras 21 días, tratados con dexametasona durante 15 días. La dexametasona fue administrada en dosis de 0,8mg /día/animal. Nuestros resultados muestran que el proceso inflamatorio crónico en la endometriosis no baja después del tratamiento con dexametasona durante 10 días, mientras que el tratamiento con dexametasona durante 15 días cambió del proceso inflamatorio crónico en la endometriosis y estimuló la proliferación de glándulas en los implantes endometriales.