EVALUATION OF GHRELIN AS A PREDICTIVE FACTOR FOR LOW BIRTH WEIGHT

• Grant number: 24/17867-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: April 01, 2025
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Maricy Apparício Ferreira
• Grantee: Thaís Gomes Faustino
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The regulation of energy metabolism is essential for the maintenance of life, especially in conditions that require improvement on energy efficiency, such as during gestation. This phase is characterized by significant metabolic changes in the female, which prioritize the needs of the developing fetus. One of the physiological pathways of energy regulation is the ghrelin/growth hormone secretagogue receptor axis, which plays crucial roles, including growth hormone secretion, glucose homeostasis, control of adiposity and body weight, in addition to contributing to cardioprotective vascular mechanisms. During gestation, ghrelin plays an important role in fetal growth and facilitates the transport of energy from the mother to the fetus. However, the scientific literature still lacks studies on the canine placenta, as well as information exploring the influence of ghrelin on the maternal-fetal relationship in this species. Thus, the objective of this study is to identify the presence of growth hormone secretagogue receptors in the canine placenta and to correlate the increased expression of these receptors with maternal and neonatal serum ghrelin concentrations, as well as unfavorable neonatal characteristics, such as low birth weight and low Apgar score. Therefore, 15 pregnant dogs and 20 puppies will be evaluated, whose placentas will be grouped according to birth weight into two groups: low birth weight and normal birth weight. Maternal and neonatal serum ghrelin will be quantified by enzyme immunoassay, while the presence of growth hormone secretagogue receptors will be investigated by immunohistochemistry, using a score that considers the intensity and percentage of immunostained cells in placental fragments. The correlation between these findings will be analyzed together with immediate neonatal parameters, such as newborn birth weight, adapted Apgar score and placental weight. Additionally, the results will also be correlated with maternal parameters, including body condition score, serum glucose, triglyceride and cholesterol levels.