How corticosterone treatment affects reproduction and wound healing in bullfrog males (Lithobates catesbianus)

• Grant number: 18/20224-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2019
• End date: December 31, 2019
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Carla Bonetti Madelaire
• Grantee: Débora Meyer de Almeida Prado
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 14/16320-7 - Impacts of climate/environmental change on the fauna: an integrative approach, AP.PFPMCG.TEM

Abstract

During reproductive season, males display high testosterone (T) levels that develop and maintain secondary sexual traits. Glucocorticoid (GC) hormones also have an important role during this period, recruiting energy stores to cope with reproductive costs. Nevertheless, the increase of CORT levels for extended periods of time can be deleterious for reproduction, diminishing T concentration and spermatogenesis. The GC also modulates immune response and may act as a mediator in the conflict of investment between immunity and reproduction. Our question is how the increase of CORT interacts with spermatogenesis status, T levels and wound healing rate in the American Bullfrog (Lithobates catesbianus) during their reproductive season. We tested if there is a relationship between the rate of wound healing and the expression of reproductive traits in males treated chronically and acutely with CORT. Animals were bought from a commercial farm and were habituated for seven days in individual plastic boxes and randomly separated into four groups: 1. Placebo (daily treated with sesame oil), 2. Acute CORT (daily treated with CORT solution [2µg]), 3. Operated sham (2 empty silastic tubes) and 4. Operated CORT (2 silastic tubes filled with CORT). After animals recovered from surgery, they were punctured in the leg with a biopsy needle. The wound was photographed and measured every 2 days in a stereomicroscopy and image analyzer software. Blood samples were collected during the experiment in order to measure CORT and T levels. Afterwards, animals were euthanized and testicles were dissected and fixed for histological analysis. The T concentration, germinative cysts diameter and gonadal maturation stage will be compared between groups and correlated with CORT plasma levels and with wound healing rate using mixed linear models.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PRADO, DEBORA M. A.; GOMES, FERNANDO R.; MADELAIRE, CARLA B.. Effects of corticosterone treatment and wound healing on reproductive traits of American bullfrogs. JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY, v. 335, n. 2, JAN 2021. (18/00406-0, 18/20224-4)

PRADO, DEBORA M. A.; GOMES, FERNANDO R.; MADELAIRE, CARLA B.. Effects of corticosterone treatment and wound healing on reproductive traits of American bullfrogs. OURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOG, v. 335, n. 2, p. 11-pg., 2021-01-07. (18/00406-0, 18/20224-4)