Vitamin D effect on embryos before implantation from diabetic rats: in vivo and in vitro studies

• Grant number: 22/15285-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2023
• End date: February 28, 2025
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal Investigator: Débora Cristina Damasceno
• Grantee: Maysa Rocha de Souza
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Maternal diabetes causes a lower number of embryonic implantations, a higher rate of embryonic death and fetal malformations due to the imbalance in the redox state induced by hyperglycemia. Vitamin D supplementation has been shown to reduce oxidative stress, plays a significant role in stimulating endocrine-pancreatic cells, and increases insulin sensitivity. In addition, there is evidence of a positive relationship between maternal vitamin D intake and offspring birth weight and bone mass. Therefore, the objective of this study will be to evaluate whether the culture medium enriched with vitamin D will lead to benefits to the developing pre-embryos (in vitro assay) after exposure to maternal hyperglycemia. We also intend to verify whether vitamin D supplementation in diabetic rats improves the development capacity and redox status of male and female pre-embryos and to relate sexual dimorphism with the repercussions found (in vivo test). For this, experimental models will be used with non-diabetic and diabetic Sprague-Dawley rats, as standardized in our laboratory. Previously, pre-embryos will be collected on day 3 of pregnancy from a diabetic intrauterine medium and will be cultured in vitamin D-enriched medium for determination of specific markers (in vitro assay). Subsequently, other rats will be used at 110 days of life, which will be supplemented with vitamin D for 15 days and in the first three days of pregnancy. On day 4 of pregnancy, the pre-embryos will be collected for morphological and redox analysis and determination of sex chromosomes to assess sexual dimorphism. The ovaries will be removed for corpora lutea counting and determination of embryonic losses before implantation. All procedures will be send to the Committee on Ethics in the Use of Animals (CEUA) of our institution. The sample size calculation determined the minimum "n" of 10 animals/group. For all statistical comparisons, a minimum confidence limit of 95% (p<0.05) will be considered. (AU)