Differential hypothalamus beta catenin expression in rats with deficient lactation.

MACKERN OBERTI JP; JAHN GA; PENNACCHIO GE; FANELLI M; NEIRA FJ; SOAJE M; VALDEZ SR

Mendoza

Congreso; XXXIV Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2016

Sociedad de Biología de Cuyo

Cadherins and catenins and their activation by Wnt proteins participate in reproductive processes and interact with PRL signaling. We examined whether changes in the expression of Wnt/catenin proteins are involved in lactation deficiency of OFA hr/hr rats by focusing on the regulation of PRL secretion at the hypothalamic level. Our first objective was to characterize the pattern of expression of β -catenin during the transition between gestation and early lactation in OFA rats compared with Sprague Dawley (SD, their strain of origin). OFA and SD rats were decapitated at 12.00 h on days 19 and 21 of gestation (G19, G21) or day 2 of lactation (L2). Serum PRL levels were measured by RIA, and β -catenin expression in the medial basal hypothalamus was determined by Western blot. Comparison of β - catenin expression through days under study, revealed that SD rats decreased β -catenin levels at G21 and reestablished their values at L2, while OFA rats decreased protein expression only at L2 (p  0.05). Comparison of β - catenin expression on the same reproductive day revealed that SD rats had significantly lower values than OFA rats at G21 (p 0.05) and higher values at L2 (p  0.05). In conclusion, SD rats diminished β -catenin protein expression at G21 while OFA reached the lowest expression at L2. These results suggest that OFA rats show altered β -catenin expression linked with an increased dopaminergic tone and impaired PRL release during lactation.