Evaluation of the consequences of limiting the litter size of rats on their birth about weight development and morphofunctional characteristics in adulthood

Author(s)

Neuziane Kloos Amorim Tavares

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2013-07-11

Examining board members

Joel Claudio Heimann; Aparecida Emiko Hirata; Rosa Maria Affonso Moyses

• Advisor: Joel Claudio Heimann

Abstract

During intrauterine life, the developing fetus is susceptible to environmental changes that can alter the phenotype of the individual in postnatal life. This phenomenon is called fetal programming. Events that occur during critical periods of rapid cell division may alter the structure and function of organ systems, resulting in consequences both early (low birth weight) and late (diseases in adulthood) in life. The experimental protocols of most of the studies on fetal programming involve a reduction in litter size soon after birth. This approach hampers the interpretation and reproducibility of the observed results. The purpose of this investigation was to determine if blood pressure, carbohydrate metabolism and energy expenditure in adult offspring are influenced by litter size. Female Wistar rats were fed standard rat chow ad libitum and were mated with male rats at 12 weeks of age. After birth, the offspring were divided into three groups: unchanged litter size (GU), culled to eight neonates (G8) and culled to four neonates (G4). At 12 weeks of age, the body weight; blood pressure; food intake; glucose, insulin, cholesterol and triacylglycerol levels; brown adipose tissue mass; adiposity index; renal mass; and cardiac mass were determined. The body weight, adiposity index, glucose level, insulin level and HOMA index were higher in males and females in the G4 group than in the G8 and GU groups. However, food consumption was lower in G4 males. The blood pressure was higher in the GU group. In summary, a small litter size is related to obesity, possible alterations in energy expenditure and insulin resistance in adult offspring (AU)

• FAPESP's process: 10/03895-0 - Evaluation of the effect of the litter size on morfo-functional characteristics of adult offspring in Wistar rats
• Grantee: Neuziane Kloos Amorim Tavares
• Support Opportunities: Scholarships in Brazil - Master