Hyperthyroidism alters mammary gland development during lactation and impairs offspring nutrition

SÁNCHEZ MARÍA BELÉN; MICHEL MARÍA CECILIA; VIRUEL LUCIANA BELÉN; NEIRA FLAVIA JUDITH; RODRÍGUEZ-CAMEJO CLAUDIO; PIETROBON ELISA OLIVIA; SOAJE MARTA; HERNÁNDEZ ANA; JAHN GRACIELA ALMA; VALDEZ SUSANA RUTH; MACKERN OBERTI JUAN PABLO

Congreso; XL Reunión Anual de la Sociedad de Biología de Cuyo; 2022

Maternal milk is a great source of bioactive components, immune factors, hormones, and nutrients which are vital for the development of the newborns. Hyperthyroidism (H) alters maternal behavior and disrupts milk production. However, it remains unclear if H could generate changes in the nutritional and immunological composition of maternal milk. Our work aimed to evaluate the influence of H on milk quality and bioactive components and if this affects developmental and immunological parameters of offspring in early lactation. To this end, 12 weeks old Wistar rats were injected with 0,25 mg/kg T4 (hyper) and vehicle (control) and euthanized on day 2 of lactation (L2). Serum, milk, and mammary gland from dams and offspring serum were obtained for further analysis. Total IgG and IgA levels from mothers and offspring serums and rat milk were analyzed by ELISA. Nutritional components like total proteins, reducing sugars (lactose), caloric value, and fat content was measured in milk. Moreover, histological analysis of the mammary gland was performed and offspring developmental, biochemical, and hormonal parameters were evaluated on L2. Our results show that H pups had lower weight on days 1 and 2 (p