IMBECU   20882
INSTITUTO DE MEDICINA Y BIOLOGIA EXPERIMENTAL DE CUYO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
EFFECT OF HYPOTHYROIDISM ON THE MOLECULAR MECHANISM OF MILK EJECTION OF MAMMARY GLAND DURING LACTATION IN THE RAT
Autor/es:
CAMPO VERDE ARBOCCO F; SASSO CV; NASIF DL; HAPON MB; JAHN GA
Lugar:
Estancia Grande
Reunión:
Congreso; XXXII REUNIÓN CIENTÍFICA ANUAL DE LA SOCIEDAD DE BIOLOGÍA DE CUYO; 2014
Institución organizadora:
SOCIEDAD DE BIOLOGÍA DE CUYO
Resumen:
During lactation the mammary gland function involves synthesis, storage and ejection of milk to the offspring. Previous results of our group showed that in the rat, hypothyroidism (hypoT) decreases milk ejection and oxytocin secretion in response to suckling, generating milk stasis and stunted offspring growth. It has been shown that oxytocin receptor (OXTR) transcription is activated by estrogen receptors (ER) mediated ER binding on ERE elements on oxtr promoter. To elucidate the mechanism by which hypoT alters mammary function we studied its effect on day 2, day 7 and day 14 of lactation (L2, L7 and L14 respectively)on serum estradiol (E2) levels by radioimmunoassay and the mammary gland ability to respond to E2by estrogen receptors and expression (ER and ER) measured by western blot and the nuclear receptor co-regulators: nuclear co-repressor 1,nuclear co-repressor 2 (ncor1 and ncor2), nuclear coactivator 1, nuclear co-activator 2 (ncoa1 and ncoa2) and oxtrby real time PCR. Our results show thathipoT decreased estradiol serum levels throughout lactation. Also hipoT decreased mammary ER, ncoa1, ncoa2andoxtr expression and increased mammary ncor1 expression altering mammary gland response toE2(p< 0.05). The decrease in E2 and ERbeta signaling may cause decrease oxtr expression that in turn, may explain the decrease in milk ejection in response to suckling.