title: Differences in the estrous cycles of Goto-Kakizaki and Wistar rats.
abstract: Goto-Kakizaki rats are an important model of type 2 diabetes, but it is difficult to maintain and expand colonies of these rats because they exhibit poor fertility. In this work, we studied the estrous cycle of Goto-Kakizaki and Wistar rats to characterize differences that might underlie these reproductive difficulties. We monitored rats from weaning to vaginal opening to assess pubertal development, and we monitored the estrous cycle and basal glycemia of each rat for 20 days at 1 month of age and at 6 months of age. At an early age we found no differences between Goto-Kakizaki and Wistar rats with respect to the onset of puberty or the periodicity of the estrous cycle. However, at 6 months Goto-Kakizaki rats spent more time in proestrus and less time in estrus each cycle, compared to Wistar rats. This delay in proceeding from proestrus to estrus could reflect a dysregulation of the hypothalamic-pituitary-gonadal axis, accompanying progression of the diabetic condition. It might also cause anovulatory cycles, which could explain the reduced reproductive capacity of Goto-Kakizaki rats.
authors.affiliation: Department of Human Anatomy and Embryology, Faculty of Medicine, University of Cádiz, Cádiz, Spain.
authors.forename: Ana Rosa Wakim
authors.initials: AR
authors.lastname: Pinto-Souza
authors.affiliation: Department of Human Anatomy and Embryology, Faculty of Medicine, University of Cádiz, Cádiz, Spain.
authors.forename: Chiara
authors.initials: C
authors.lastname: Firetto
authors.affiliation: Department of Human Anatomy and Embryology, Faculty of Medicine, University of Cádiz, Cádiz, Spain.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Pérez-Arana
authors.affiliation: Department of Child and Mother Health and Radiology, Pediatric Endocrinology, Puerta del Mar University Hospital, University of Cádiz, Cádiz, Spain.
authors.forename: Alfonso María
authors.initials: AM
authors.lastname: Lechuga-Sancho
authors.affiliation: Department of Human Anatomy and Embryology, Faculty of Medicine, University of Cádiz, Cádiz, Spain.
authors.forename: José Arturo
authors.initials: JA
authors.lastname: Prada-Oliveira
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D012098:Reproduction; D012741:Sexual Maturation / Q000502:physiology; D013045:Species Specificity