title: Effect of steroid hormones on Bufo arenarum oviduct. Ultrastructural study.
abstract: The endocrine regulation of the mucosa of the oviductal pars convoluta was analyzed by ultrastructural studies demonstrating that ovariectomy, together with a decrease in ovarian steroids circulating levels, caused a marked regression in this portion of Bufo arenarum oviduct. Twenty-five days after ovariectomy, a decrease in the depth of the epithelial and glandular layers was observed due to the notable loss of secretory cells, whose number was clearly smaller than in nonovariectomized females. The remaining secretory cells showed involution signs, with few secretory granules in their cytoplasm, little endoplasmic reticulum near poorly developed Golgi complexes and a large amount of lipid droplets. Cells in an advanced autolysis state were found in the lumen. These characteristics evidence a nonfunctional state of the pars convoluta. Treatment with 5alpha-dihydrotestosterone (DHT) completely reversed the ovariectomy effect, inducing pars convoluta growths and restoring the characteristics of epithelial and glandular secretory cells in the whole pars convoluta, with micrographs similar to the control. These same effects were observed after treatment with estradiol-17beta (E2), progesterone (P) o E(2)+P in the glandular layer of the whole pars convoluta, but only in the epithelial layer of the most anterior region of this duct. In the secretory cells of other segments these treatments induced the formation of granules of high electron density and homogeneous aspect. Each steroid had a particular effect on the pars convoluta. Although E2 and DHT induced the development of the organoids involved in the proteins biosynthesis, P and DHT acted as secretagogues.
authors.affiliation: Department of Developmental Biology, National Council for Scientific and Technical Research, National University of Tucumán, Chacabuco 461, (4000) Tucumán, Argentina. mmedina@fbqf.unt.edu.ar
authors.forename: Marcela Fátima
authors.initials: MF
authors.lastname: Medina
authors.forename: Claudia Alejandra
authors.initials: CA
authors.lastname: Crespo
authors.forename: Inés
authors.initials: I
authors.lastname: Ramos
authors.forename: Susana Beatriz
authors.initials: SB
authors.lastname: Cisint
authors.forename: Silvia Nélida
authors.initials: SN
authors.lastname: Fernández
mesh_terms: D000818:Animals; D002022:Bufo arenarum / Q000033:anatomy & histology*; D013196:Dihydrotestosterone / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006728:Hormones; D010052:Ovariectomy; D010057:Oviducts / Q000187:drug effects* / Q000648:ultrastructure*; D011374:Progesterone / Q000494:pharmacology*; D013256:Steroids / Q000097:blood
chemical_list: D006728:Hormones; D013256:Steroids; D013196:Dihydrotestosterone; D011374:Progesterone; D004958:Estradiol