Hyperthyroidism alters immune milk quality and offspring nutrition.

LUCIANA VIRUEL; MARÍA BELÉN SÁNCHEZ; CECILIA MICHEL; JUAN MANUEL RÍOS,; JUAN PABLO MACKERN

San Luis

Congreso; Congreso de la Sociedad Argentina de Inmunología 2023; 2023

Sociedad Argentina de Inmunología

Hyperthyroidism (hyperT) alters maternal behavior and disrupts milk production in experimental models. However, it remains unclear if hyperT could change maternal milk´s nutritional and immunological composition. We investigated the influence of hyperT on milk quality, bioactive components, offspring development, and immunity in early lactation. To this end, 12-week-old Wistar rats were injected with 0.25 mg/kg T4 (hyperT n=20) and vehicle (control n=19), mated with Wistar male rats and euthanized on day 2 of lactation (L2) to address this objective. Serum, spleen and milk from dams and offspring serum were obtained for further analysis. Milk was obtained after ketamine/xylazine sedation and oxytocin stimulation for milking. Total IgG, IgG2a and IgA levels from mothers and offspring serums and milk were determined by ELISA. Nutritional components: total proteins, reducing sugars (lactose), energy, and fat content were measured in milk. Moreover, offspring developmental, biochemical, and hormonal parameters were evaluated on L2. To assess whether maternal hyperT may have an immune systemic effect, we analyzed the splenic weight and splenic index in dams on L2. HyperT dams displayed higher serum levels of T4 and corticosterone than control mothers. By contrast, T4 and corticosterone levels were reduced in offspring from hyperT mothers (p