LONG-TERM EFFECTS OF MATERNAL MILD HYPERTHYROIDISM ON THE DEVELOPMENT AND THE BEHAVIOR OF OFFSPRING IN ADULTHOOD

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

Mendoza

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

Sociedad de Biología de Cuyo

Abnormal levels ofthyroid hormones (THs) are associated with alterations in anxiety andcirculating hormones such as glucocorticoids (GCs) and prolactin affectingfertility and reproductive success. However, little is known about thelong-term effects of maternal hyperthyroidism on the development and behaviorof their offspring. For this purpose, eight pregnant Wistar rats were dividedin two groups defined as: Control (Euthyroid, n=4) and HyperT (n=4).Hyperthyroidism was induced with T4 0.1mg/kg/day, s.c. Afterdelivery, on day 2 of lactation, the number of pups in each litter wasstandardized to eight and the offspring allowed to growth under standardcondition. Development parameters were recorded from birth to 42 postnatal day(PND). Adult female and male offspring (PND 85-100) were subjected to the OpenField Test (OFT) to evaluate locomotor activity using EthoWatcher computacionaltool. The parameters assessed were as follows: a) rearings, b) entries to areasof interest, c) total distance traveled. At PND 100-120, the adult offspringwere sacrificed, trunk blood was collected for serum hormonal determinationsand adrenal glands (AG) dissected for histological analysis using Image Jprogram. We found that offspring from HyperT mothers (named HyperT pups)presented alterations in the postnatal development of some physical, sensory,motor, and reproductive parameters compared to offspring of euthyroid mothers(named Control pups). Body length at PND 1 was lower in HyperT pups (p<0.001) while there were delaysin the eye opening (p<0.01), ear canal opening (p<0.05), forelimb grasp (p<0.05),auditory startle (p<0.001), testicular descent (p<0.01), vaginal opening (p<0.05)in HyperT pups compared to Control pups. In the OFT, adult female and male pups showed different behaviours in locomotoractivity and exploration: female HyperT pups exhibited greater distancetraveled (p<0.01), increased number of entries to areas of interest(p<0.01) and of rearings (p<0.05) compared to Control female pups. Inaddition, female HyperT pups showed increased entries and time spent in the centerof the square (p<0.01) and number of rearings (p<0.05) compared to maleHyperT pups. At PND 100-120, we found an increased size of the AG zona fasciculata (GCs synthesis zone) inadult female HyperT pups compared to adult female Control pups (636,6 ± 40,01 vs 451,0 ±10 arbitrary units p<0.01, while there wasno differences between male of both group. Also, at PND 100-120 the basal serumcorticosterone levels were similar in both male and female Control and HyperT rats.These results show that a maternal mild hyperthyroidism may have long- termeffects on physical and neurological development of the offspring triggering sex-dependentbehavioral consequences in adulthood.@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:10.0pt;margin-left:0cm;line-height:115%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:Calibri;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:11.0pt;mso-ansi-font-size:11.0pt;mso-bidi-font-size:11.0pt;font-family:Calibri;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}.MsoPapDefault{mso-style-type:export-only;margin-bottom:10.0pt;line-height:115%;}div.WordSection1{page:WordSection1;}