title: Treatment with eCG decreases the vascular density and increases the glandular density of the bovine uterus.
abstract: The uterus plays an essential role in mammalian reproduction and is a target of several hormonal protocols used to improve fertility in cattle. Many studies highlighted the importance of eCG treatment following fixed-time artificial insemination in improving follicular growth, ovulation and pregnancy rates in cattle. Moreover, eCG has been implicated in angiogenesis, leading to important changes in uterine blood flow and vascularisation. However, there is still a lack of information regarding the specific alterations induced by eCG upon glandular and vascular characteristics of bovine uterus. To investigate the influence of eCG on: uterine thickness and area; uterine artery diameter and area; uterine vascular and gland density; and the expression of the VEGFA-system, the uteri of crossbred beef cows were collected. All cows were submitted to follicular wave emergence synchronization. On day four of protocol, cows submitted to superovulation (n = 6) received 2000 IU eCG, on day eight, after expected follicular deviation, cows submitted to stimulatory treatment (n = 5) received 400 IU eCG. Control cows (n = 5) did not receive eCG. On day five po cows were subjected to ultrassonographic evaluation and slaughtered for uterine tissue sampling on day six po. Uterine vessels and glands were quantified by the counting point stereological method. The VEGFA-system was localized in different cellular types, showing no qualitative or quantitative differences in the site of expression or the intensity of the positive signal among the groups. Vascular density was decreased in the endometrium of stimulated and myometrium of superovulated cows compared with the control ones, which showed higher vascular density in the myometrium and endometrium of the ipsilateral uterine horn. The uterine gland density was higher in superovulated compared with stimulated and control cows. Thus, we can infer that stimulatory or superovulatory treatments with eCG influence the vascular density in the endometrium and myometrium in cattle.
authors.affiliation: Department of Surgery, Faculty of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Mona e Pinto
authors.forename: V
authors.initials: V
authors.lastname: Pavanelo
authors.forename: L
authors.initials: L
authors.lastname: Alves de Fátima
authors.forename: L M
authors.initials: LM
authors.lastname: Medeiros de Carvalho Sousa
authors.forename: G
authors.initials: G
authors.lastname: Pacheco Mendes
authors.forename: R
authors.initials: R
authors.lastname: Machado Ferreira
authors.forename: H
authors.initials: H
authors.lastname: Ayres
authors.forename: P
authors.initials: P
authors.lastname: Sampaio Baruselli
authors.forename: F
authors.initials: F
authors.lastname: Palma Rennó
authors.forename: P
authors.initials: P
authors.lastname: de Carvallo Papa
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D004717:Endometrium / Q000098:blood supply / Q000187:drug effects; D004973:Estrus Synchronization; D005260:Female; D015870:Gene Expression; D006064:Gonadotropins, Equine / Q000008:administration & dosage*; D007150:Immunohistochemistry; D009215:Myometrium / Q000098:blood supply / Q000187:drug effects; D010062:Ovulation Induction; D011247:Pregnancy; D013480:Superovulation; D014463:Ultrasonography; D055988:Uterine Artery / Q000033:anatomy & histology / Q000187:drug effects; D014599:Uterus / Q000033:anatomy & histology* / Q000098:blood supply* / Q000000981:diagnostic imaging; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000235:genetics
chemical_list: D006064:Gonadotropins, Equine; D042461:Vascular Endothelial Growth Factor A