Early embryo redox status according to the experimental model of maternal diabetes

Author(s)

Aline Bueno

• Document type: Doctoral Thesis
• Press: Botucatu. 2016-11-08.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina. Botucatu
• Defense date: 2016-08-26
• Advisor: Débora Cristina Damasceno; Felipe Perecin

Abstract

Early embryos recovered from diabetic rats show increased number of blastomeres undergoing apoptosis and decreased total number of blastomeres, suggesting impaired litter size and newborn weight. This might increase the chances of metabolic disorders in adulthood of these animals. Since diabetes-induced hyperglycemia impairs the redox balance, the aim was to evaluate the embryonic oxidative stress status before the implantation in order to identify whether there are differences in levels of oxidative stress in early embryos from diabetic dams. Thus, we hypothesized the decreased cell number found in early embryos recovered from diabetic rats is due to the low embryonic ability to maintain their own redox balance. Our study shows that rats with streptozotocin-induced mild and severe diabetes present impaired redox status in early pregnancy. This maternal unbalance directly influences the embryonic redox status, reflecting the increased reactive oxygen species in the morula stage. We also showed that regardless of hyperglycemic level the embryos trigger defense mechanisms involved in the excessive free radical scavenging as an attempt to survive. Nevertheless, the success of this defense mechanism seems to depend on maternal hyperglycemia, highlighting the importance of the programmed pregnancy as well as appropriate medical care starting in early stages of human diabetic pregnancy. (AU)

• FAPESP's process: 11/23721-0 - Antioxidant system role and gender influences on the in vivo developmental competence of embryos at different models of experimental diabetes
• Grantee: Aline Bueno
• Support Opportunities: Scholarships in Brazil - Doctorate