Antiestrogen U23,469 induced alterations of catecholamine levels on plasma and central nervous system

The effect of antiestrogen U23,469 administration in vivo on the centration of dopamine, norepinephrine and epinephrine in the plasma, cerebral cortex and hypothalamus in ovariectomized rats was investigated. Rats were treated with estradiol benzoate, progesterone and U23,469 in different doses, s.c., daily for 6 days. Control group was injected with sesame oil. Catecholamines were estimated by radioenzymatic assay. Six days of U23,469, estradiol benzoate, progesterone or its combination altered the catecholamine levels compared to the control. Dopamine decreased in plasma with progesterone and U23.469. In the cerebral cortex, progesterone and U23,469 increased significantly and in the hypothalamus all the treatments produced a decrease of catecholamines. The levels of NE were reduced with estradiol benzoate, progesterone and U23,469; there was no significant difference in the norepinephrine levels after different treatments in the cerebral cortex, but the NE levels were significantly decreased inthe hypothalamus. Epinephrine Showed differences related to the treatment, as in plasma, as in cerebral cortex and hypothalamus. These resultas suggest that antiestrogen treatment compared with the estradiol benzoate or progesterone may affect the catecholamine levels of the central nervous system and plasma and support the idea that AE could have an indirect effect on the catecholaminergic system

Sexual differences in the brain catecholamine content in four species of tropical bats

Se estudieron las catecolaminas -dopamina, norepinefrina y epinefrina- en el cerebro de machos y hembras de cuatro especies de murciélagos tropicales, con diferentes hábitos de alimentación (insectívero, frugívoro, omnívero y polinívero). Estos fueron capturados cerca del Túnel del Arco, estructura de un acueducto que corre en un bosque tropical caducifolio cuya temperatura anual media es 25.8-C. Las tres catecolaminas se encuentran presentes en el cerebro de todas las especies estudiadas y muestran diferencias estadísticamente significativas tanto entre especies, como entre sexos. Mientras la dopamina y la norepinefrina son consistentemente más elevadas en los machos, la epinefrina lo es en las hembras. Estos hallazgos sugieren que los cambios en los niveles de las catecolaminas se encuentran intimamente ligados al patrón reproductivo de cada especie e involucrados en funciones cerebrales importantes, tales como la conducta, la integración endocrina y la diferenciación sexual del cerebro. El ambiente, la dieta y el sexo posiblemente participan en los mecanismos de adaptación de estas especies a su entorno