SUMMARY OBJECTIVE To evaluate the ovarian effects of melatonin (Mel) in a rat model of polycystic-ovary-syndrome (PCOS) before and after permanent estrus induction. METHODS Thirty-two adult-female rats with regular estrous cycle were equally divided into four groups: 1) GCtrl – at estrous phase. 2) GPCOS - at permanent-estrous phase. 3) GMel1 – treated for 60 days with Mel (0.4 mg/Kg) during permanent estrus induction and 4) GMel2 – rats with PCOS and treated for 60 days with Mel. After that, the animals were euthanized, and the ovaries were removed and processed for paraffin embedding. Sections were stained with H.E. for histomorphometry or subjected to immunohistochemistry for Ki-67 and cleaved caspase-3 (Casp-3) detections. RESULTS The GPCOS showed lack of corpus luteum and several ovarian cysts, as well as interstitial-like cells. The presence of corpus luteum and a significant increase in primary and antral follicles were observed in Mel-treated groups, which also showed a decrease in the number of ovarian cysts and in the area occupied by interstitial-like cells. These results were more evident in GMel1. The percentage of Ki-67-positive cells was significantly higher in the Mel-treated groups, mainly in the GMel2, as compared to GPCOS. On the other hand, the percentage of Casp-3-positive cells was significantly lower in granulosa cells of GMel1, whereas it was significantly higher in the interstitial-like cells of GMel2, in comparison to GPCOS. CONCLUSION Melatonin administration prevents the permanent estrus state in the PCOS rat model. This effect is more efficient when melatonin is administered before permanent estrus induction.
Objective: To evaluate the histomorphometric and immunohistochemical changes in interstitial cells and ovarian follicles of rats treated with metformin during and after induction of permanent estrus. Methods: Thirty-two adult-female rats with regular estrous cycle were equally divided into four groups: 1) GCtrl - at estrous phase. 2) GPCOS - at permanent-estrous phase. 3) GMet1 - rats and daily treated with metformin (12.5 mg/Kg) during 60 consecutive days, as preventive form and 4) GMet2 - PCOS rats, which remained exposed to 60 days of continuous illumination and treated with metformin. After that, the animals were euthanized, and the ovaries were removed and processed for paraffin embedding. Sections were stained with H.E. for histomorphometry or subjected to immunohistochemistry for Ki-67 and cleaved caspase-3 (Casp-3) detections. Results: The GPCOS showed lack of corpus luteum and several ovarian cysts, as well as interstitial-like cells. The presence of corpus luteum and a significant increase in primary and antral follicles were observed in Mel-treated groups, which also showed a decrease in the number of ovarian cysts and in the area occupied by interstitial-like cells. The presence of corpus luteum along with an increase in the number of primary follicles in the Met2 group were noticed (p<0,01). A significant reduction in number of cysts and in the area occupied by interstitial cells, as well as a decrease in nuclear volume of interstitial cells, were noticed in the Met-treated groups, mainly in the Met2 group. The percentage of cell proliferation was significantly higher in granulosa cells of the Met-treated groups than PCOS group, mainly in the GMet2 (p<0,01), which was similar to the GCtrl group. On the other hand, the percentage of apoptosis (cleaved-caspase-3- positive cells) was significantly higher in the granulosa cells of GPCOS and Met-treated groups than the GCtrl group, but without significant difference, which showed weak cleaved caspase-3 immunoreactivity in those cells. Conclusion: The ovaries of rats treated with metformin showed a decrease in nuclear volume and in the area occupied by interstitial cells, presence of corpus luteum, in addition to a decrease in the number of cysts.
Objetivo: Avaliar os efeitos da melatonina, metformina e citrato de clomifeno no endométrio de ratas modelo de síndrome dos ovários policísticos. Métodos: Setenta e oito ratas foram divididas em 13 grupos e dois experimentos (prevenção e tratamento). Após as exposições todos os animais foram anestesiados e tiveram retirados os cornos uterinos e submetidos a coloração pela hematoxilina e eosina e imunoistoquímica (Ki-67 e Vegf). Os dados obtidos foram submetidos ao teste t de Student (p<0,05). Resultados/Conclusão: A melatonina, a metformina e o citrato de clomifeno não promovem efeitos proliferativos e angiogênicos no endométrio de ratas em estro permanente, porém, a melatonina tem efeito trófico mais significativo no estroma endometrial, o que não interferiu na sua espessura, enquanto que a metformina apresentou efeito trófico mais significante no epitélio glandular do endométrio, portanto, estes efeitos são semelhantes tanto antes quanto após a indução de SOP por exposição à luz contínua.
It is well known that the blood fibrinogen is highly increased after trauma (Chanutin, Hortensstine, Cole and Ludewig, 1938). Henriques, Henriques and Selye (1950) observed that this response to trauma is significantly smaller in the adrenalectomized rat.It seems obvious that in the normal rat the fibrinogen response to trauma could depend on the presence of the adrenal cortex, the adrenal medulla or both. The first possibility is suggested by the knewn fact that cortical hormones influence protein metabolism (Forsham, Thorn, Bergner and Emerson, 1946;Ingle and Prestrud, 1948;Engel, Schiller and Pentz, 1949) while the role of the adrenal medulla is indicated by the fact that epinephrine injections cause an increase in fibrinogen (Henriques, Henriques and Mattos, 1950).We therefore decided to study the effect of trauma upon blood fibrinogen in adrenal demedullated rats. MATERIAL AND METHODSFour groups of male Wistar rats, weighing 100 to 150 gm. were used in this experiment. In group I adrenal enucleation was performed, group II was totally adrenalecto-
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