INVESTIGADORES
SCAIA Maria Florencia
congresos y reuniones científicas
Título:
Aromatase activity in Bidder´s organ of Rhinella arenarum (Amphibia, Anura)
Autor/es:
SCAIA MARIA FLORENCIA; CEBALLOS NORA RAQUEL
Reunión:
Congreso; II Reunión Conjunta de las Sociedades de Biología de la República Argentina; 2011
Resumen:
The Bidder organ (BO) of male true toads of Bufonidae family is located in the anterior pole of the testis and it has been compared to a rudimentary ovary because of the presence of previtellogenic follicles. The presence of several steroidogenic enzymes has been detected in BO from adult males of Rhinella arenarum and, since testes lack aromatase activity, plasma estradiol may be synthesized by BO. The purpose of this study was to analyze annual variations in plasma estradiol levels and also in aromatase activity in BO. Enzimatic activity was determined in homogenates of BO and plasma estradiol levels were measured by radioimmunoassay. Lowest levels of plasma estradiol are registered during the pre reproductive season (PreR, 0,39±0,01 ng/ml), they increase during the reproductive season (R, 0,90±0,02 ng/ml) and achieve highest levels during the post reproductive season (PostR, 1,34±0,04 ng/ml). Moreover, during PreR season total aromatase activity is significantly lower than during the rest of the year (PreR, 3,66±1,46 pmol*min; R, 13,56±4,15 pmol*min; PostR, 16,20±9,47 pmol*min). Taken together, these results suggest that the BO is the main source of plasma estradiol.