HYPERTHYROIDISM ALTERS MAMMARY GLAND DEVELOPMENT DURING LACTATION AND IMPAIRS OFFSPRING NUTRITION

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

Mendoza

Congreso; XXXIX Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2022

Sociedad de Biología de Cuyo

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 andimmunological composition of maternal milk. Our work aimed to evaluate theinfluence of H on milk quality and bioactive components and if this affectsdevelopmental and immunological parameters of offspring in early lactation. Tothis end, 12 weeks old Wistar rats were injected daily with 0,25 mg/kgT4 s.c. (hyper) and vehicle (control), mated and euthanized on day 2 oflactation (L2). Serum, milk, and mammary gland from dams and offspring serumwere obtained for further analysis. Total IgG and IgA levels from mothers andoffspring serums and rat milk were analyzed by ELISA. Nutritional componentslike total proteins, reducing sugars (lactose), caloric value, and fat contentwere measured in milk. Moreover, histological analysis of the mammary gland wasperformed and offspring developmental, biochemical, and hormonal parameterswere evaluated on L2. Our results show that H pups had lower weight on days 1and 2 (p<0,001), less weight gain, and diminished length, cerebralweight, and head circumference (p<0,001). T4 and corticosterone levels were reduced in pups of Hmothers (p<0,001 and p<0,01) and glucose and albumin serumlevels were reduced too (p<0,01). Concerning the mammary gland, thealveolar area and mammary adipose tissue (p<0,01) were significantlylower and the mammary connective tissue was higher in the hyper group than inthe control group (p<0,05). Furthermore, in the whole mount mammarygland analysis, we observed a diminished epithelial elongation (p<0,05). We found that H milk displayed a reducedcaloric value and fat concentration (p<0,01) without changes in totalIgG in serum and milk of mothers and offspring serum and milk IgA. Inconclusion, H affects offspring parameters and mammary gland development inearly lactation. H may alter the energy intake without affecting humoral immunityin the offspring.@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-536870145 1107305727 0 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-536870145 1073786111 1 0 415 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin-top:0cm;margin-right:0cm;margin-bottom:8.0pt;margin-left:0cm;line-height:107%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:Calibri;mso-fareast-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-ansi-language:ES-AR;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:10.0pt;mso-ansi-font-size:10.0pt;mso-bidi-font-size:10.0pt;font-family:Calibri;mso-ascii-font-family:Calibri;mso-fareast-font-family:Calibri;mso-hansi-font-family:Calibri;}div.WordSection1{page:WordSection1;}