PRENATAL D-AMPHETAMINE EXPOSURE INFLUENCES PROLACTIN SYNTHESIS AND SECRETION IN RESPONSE TO STRESS AND ESTROGEN IN ADULTHOOD.

SANTONJA, FLORENCIA; PIETROBON, ELISA; NEIRA, FLAVIA; MORENO SOSA, TAMARA; JAHN, GRACIELA ALMA; BREGONZIO, CLAUDIA; SOAJE, MARTA

Mar del Plata

Congreso; LXIV Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2019

Abstract/Resumen: The dopaminergic system, a main regulator of prolactin (PRL) secretion, is closely involved in the responses to stress and amphetamine. The ovarian steroids modulate PRL secretion and several aspects of stress responses. Previously, we found that prenatal exposure to amphetamine (PEA) induced changes in pituitary mRNA D2R expression during adulthood. Our present aim was to study PEA effects and the influence of estrogen (E2) on pituitary D2R expression (protein) and their correlation with pituitary PRL content (mRNA and protein levels) in adult OVX rats in response to stress. Moreover, we also explored the role of E2 in response to stress on the expression of de pTH-Ser 40 in the medium basal hypothalamus (MBH) of OVX adult rats in PEA animals. For these purposes, female Wistar rats were treated daily with D-amphetamine 2.5 mg/kg i.p./saline during days 15 to 21 of pregnancy. Their female offspring were OVX at day 60; 15 days later treated with estrogen/oil (E2; 2 x 5 μg/rat/24 h) and exposed to immobilization stress during 30 min. Blood and tissue samples were collected for corticosterone by RIA and pituitary D2R and PRL content by real time PCR and Western blot (WB) determinations. pTHSer-40 expression was determined by WB in MBH extracts. Data were analyzed using two-way ANOVA and Student´s-t test. Pituitary D2R expression (protein) was diminished only in PEA OVX+E2 rats (p<0.05) and no effects of stress were observed. E2 increased PRL mRNA levels in control and PEA OVX rats (p<0.05) and prevented the effect of stress. Stress diminished PRL pituitary content (protein) in control rats with E2 and the PRL protein in PEA rats independent of E2 treatment (p<0.05). Moreover, stress decreased MBH p-TH in PEA OVX+E2 rats (p<0.05). Thus, prenatal treatment with D-amphetamine sensitizes the hypothalamus-pituitary system affecting PRL synthesis and secretion in response to stress and E2.