Deficient lactation by spontaneous central hypoprolactinemia in OFA rats alters lymphoid organs and increases natural antibodies in the offspring

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

Congreso; LXXI Reunión Anual de Sociedad Argentina de Inmunología; 2023

Prolactin is a lactogenic hormone that plays a vital role in developing the mammary epithelium and synthesizing milk for proper breastfeeding. Maternal milk is an excellent source of bioactive components, immune factors, hormones, and nutrients vital for the offspring´s development. Our laboratory has worked for many years with an experimental model of deficient breastfeeding in rats associated with low prolactin levels (hypoprolactinemia or hypoP) during early lactation, known as Oncins France Colony A (OFA). Our work aimed to evaluate the influence of hypoP on milk quality and bioactive components and whether this affects offspring´s developmental and immunological parameters in early lactation. To this end, 12-week-old Sprague Dawley (SD- control group n=7) and OFA (hypoP group n=12) rats were mated and euthanized on day 2 of lactation (L2). Serum, spleen, milk, and mammary glands from dams and offspring serum, and several organs were obtained for further analysis. Prolactin serum levels were analyzed by RIA. Total IgG and IgG2a in maternal serum and milk and offspring serum were analyzed by ELISA. Moreover, natural IgG anti-DNP (dinitrophenols) was evaluated in offspring and L2 dam serum. Milk nutritional components like total proteins, reducing sugars (lactose), caloric value, and fat content were measured. Also, histological analysis of the mammary gland was performed, and offspring developmental parameters were evaluated on L2. Our results show that OFA rats had lower prolactin levels than SD rats (p