Numerous hypotheses have been proposed about the pathogenia of the polycystic ovarian syndrome (PCOS). However, hormonal control of the persistent follicle has not been established. The objective of the present study was to compare the follicular structure and hormonal profiles of rats treated with adrenocorticotrophic hormone (ACTH) with two experimental models of PCOS. ACTH-treated animals were compared with those exposed to continuous light, treated with estradiol valerate, and control (in proestrous and diestrous). Serum hormone levels, histomorphometrical changes, and immunoexpression of vimentin, cytokeratins, cadherins, and proliferating cell nuclear antigen (PCNA) were examined. Treatment with ACTH resulted in an elevation of corticosterone secretion with LH reduction but without changes in ovarian morphology. Although stress (or ACTH) stimulation may be only one pathophysiological mechanism involved in follicular cyst pathogenia in other species, we do not find important evidence to suppose that this would happen in rats.Fil: Baravalle, Celina. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Departamento de Ciencias Morfológicas. Laboratorio de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salvetti, Natalia Raquel. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Departamento de Ciencias Morfológicas. Laboratorio de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mira, G. A.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Lorente, J. A.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Ortega, Hugo Hector. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Departamento de Ciencias Morfológicas. Laboratorio de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
