Estrógeno sulfotransferasa y estrógeno sulfatasa uterinas en la implantación embrionaria / Uterine estrogen sulfotransferase in embryo implantation

La relación estrógenos conjugados/no conjugados, asociada con procesos reproductivos, ha despertado el interés de estudiar el papel biológico y el control de la estrógeno sulfotransferasa y estrógeno sulfatasa que participan en la formación e hidrólisis de los estrógenos 3-sulfato, respectivamente. En este trabajo se determinó la actividad de las dos enzimas a través de la convesión recíproca de estrona sulfato-H3 y estrona-H3 en los sitios de implantación (SI) y áreas no implantadas (SNI) del útero de ratas durante el proceso de implantación embrionaria. En estos tejidos se observó un contraste en las actividades enzimáticas. En tanto que la sulfotransferasa en SI fue mayor que en SNI (0.205) pg vs. 0.144 pmola/mg proteína/h), la actividad de sulfatasa se presentó en forma inversa (1.470 y 1.977 pmolas/ mg proteína/h respectivamente). Estos resultados indican la presencia simultánea de ambas anzimas en el útero de rata y sugieren la existencia en SI de un mecanismo que regula la concentración local de estrógenos libres y sulfoconjugados en el que participan dichas enzimas

Effect of estradiol implanted in the corticomedial amygdala on the sexual behavior of castrated male rats

1. The purpose of the present investigation was to study the effect of ß-estradiol crystals implanted in the corticomedial area of the amygadaloid body on the sexual behavior of castrated male rats. 2. The animals were divided into the following groups: group I (N=9), castrated rats; group II (N=4), rats which had been castrated and stereotaxically implanted with cholesterol, both groups being used as controls; group III (N=6), castrated rats con estradiol implants. Latency to the first anogenital exploration, latency to the first mount and mount frquency were determined during the pre-castration and post-castration phases and after the material had been implanted in groups II and III in 10-min observation sessions. 3. There was diminished sexual behavior of the animals in group I without spontaneous recurrence within the period observed. Group II animals, who had undergone implantation of cholesterol, an inert substance, maintained low levels of sexual behavior (post-castration 0.8 ñ 7 vs 0.0 ñ 0.0 and 0.5 ñ 0.5 on the 6th and 9th day afther implantation, repectively). Group III animals presented a gradual increase in the number of mounts (from post-castration 1.2 ñ 0.5 to 6.5 ñ 2.7 and 4.1 ñ 1.0 on the 6th and 9th day after implantation, respectively) and a decrease of mount latency (from post-castration 431.2 ñ 55.9 to 226.1 ñ 119.6 and 51.0 ñ 28.9 on the 6th and 9th day after implantation, respectively) reaching pre-castration levels on the 6th and 9th day after ß-estradiol implantation. 4. We conclude that, under the effect of estradiol, the amygdaloid region can modulate male sexual behavior, thus injdicating a physiological role for estradiol receptors present in this area