Ovarian function and fertility preservation in prepubertal rats submitted to cryopreservation of ovarian tissue and chemotherapy

• Grant number: 18/17605-6
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2019
• End date: November 30, 2021
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Simone de Campos Vieira Abib
• Grantee: Simone de Campos Vieira Abib
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated researchers: Amanda Begatti Victorino Monteiro ; Edson Guimarães Lo Turco ; Maria Teresa de Seixas Alves ; Renato Fraietta ; Talita Picinin Amianti

Abstract

The treatment of children and adolescents with cancer has advanced in recent decades leading to an overall survival rate close to 80%. As a result, we have a population of surviving adults with long-term sequelae, among them infertility. The available methods for fertility preservation for women are oophoropexy, in selected cases, and cryopreservation of embryos or oocytes, but those are available only for adults. Ovarian tissue cryopreservation in prepubescent children has been offered in some oncology services as an experimental method. Literature has few studies about prepubescent ovaries and none that include chemotherapy in the experimental model. The present study aims to evaluate ovarian function and fertility in prepubertal rats submitted to cryopreservation of ovarian tissue and chemotherapy. Eighty Wistar rats aged 21 days divided into eight groups. Groups 1, 3, 5 and 7 (control) will undergo oophorectomy first. On day 23 they will receive chemotherapy (ciclosporin 100mg / kg in group 1, ifosfamide 200mg / kg in group 3, cyclophosphamide 50mg / kg + ifosfamide 100mg / kg in group 5 and saline solution 0.9% in group 7). Groups 2, 4, 6 and 8 (Sham) will receive chemotherapy at day 21 (cyclophosphamide 50mg / kg in group 2, ifosfamide 100mg / kg in group 4, cyclophosphamide 50mg / kg + ifosfamide 100mg / kg in group 6 and saline 0, 9% in group 8). When they reach the 23rd day of life, oophorectomy will be performed in groups 2, 4 and 6 and laparotomy without oophorectomy in group 8. On the 45th day of life, all animals will be submitted to a frozen ovary reimplantation at anatomical site. With 50 days of life the analysis of estrous cycle will be initiated and at day 60 they will be placed with males for copulation and observation of pregnancy for a period of 30 days, when they will be then submitted to euthanasia at 90 days. The analysis will be made about presence or absence of estrous cycle, presence or absence of pregnancy and index of follicles in the reimplanted ovary with or without chemotherapy. (AU)