61. THYROXINE EXCESS INCREASES FETAL GROWTH, PLACENTAL AND MILK IMMUNE CELL INFILTRATION IN LATE PREGNANCY AND EARLY LACTATION

SANCHEZ, MARÍA BELÉN; MACKERN OBERTI JP

San Luis

Congreso; XXXVII Reunión Anual Científica de la Socidad de Biología de Cuyo 2019. San Luis. 5-6 de diciembre de 2019.; 2019

Thyroid dysfunctions cause reproductive disorders that lead to preterm birth and profound endocrine alterations during lactation with deficient milk production and quality. Currently, whether thyroid hormones (THs) modulate immune cells in maternal milk and placenta is unknown. Therefore, the aim of our work was to assess the influence of hyperthyroidism (hyper) on placental immune cells as well as its impact in pregnancy and lactation. To this end, 10-12 weeks old Wistar rats were injected with a daily dose of T4 (0.1 or 0.25 mg/kg s.c) to induce hyper, or vehicle in control animals. Rats were mated 8 days after starting T4 treatment and euthanized on day 19 (G19), 20 (G20) of gestation and 2 of lactation (L2). Placenta samples and milk were minced to reach single cell suspension and dyed. Then, resident placental and milk immune cells (CD45+, CD3+, CD11b/c+) were analyzed by flow cytometry and mRNA content of hormone receptors by qPCR. Also, placental (G19-20), fetus (G19-20) and offspring weights were measured. The fetuses of hyper 0.25 mg/kg mothers weighed more in G19 and G20 (p