To investigate the efects of copper-deficiency on spontaneous closure of ductus arteriosus in newborn rats, an experimental model consisting in three groups of ten female Sprague-Dowley rats each was used. Group I rats, copper-deficient, were fed a copper-free diet from 35 days before pregnancy until birth. Group II, control rats, were given a diet containing appropriate amounts of copper [6 ppm) and energy. Group III, the pair-fed rats, received a diet that was adecuate in copper content but

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... stricted in energy to the same caloric ingestion previously shown by copper deprived rats. The ductus arteriosus of 10 newborn rats of each group were studied by hystological methods at sometime between the third and twelfth hour of life, and it was patent in 100%, 20% and 40% of the cases of copper deprived, control and pair fed rats respectively (Chi square test, p -0-0009)-The wall thickness of patent ductus from copper deprived rats were significantly lower than those from rats of the other two groups (Kruskall-Wallis Test; p = 0.0079). Our results suggest that materno-fetal copper deficiency significantly affects the spontaneous closure rate of the ductus arteriosus in the rat. The mechanism of this abnormal response probably includes structural changes in the ductal wall, alterations in the energy yield process or abnormal regulation of prostaglandins E2 and F2 -asynthesis, (El significado biologico del cobre fue evidenciado por primera vez en el afio 1928 cuando Hart y cols, demostraron su esencialidad en la smtesis de hemoglobina en la rata 1 . No obstante, no fue sino hasta el afio 1956 cuando se describio por primera vez un estado carencial en el ser humano 2 . Desde entonces, numerosas publicaciones tratan sobre estados de deficiencia de cobre, con especial referenda a la prematuridad, sindromes de malabsorcion y nutricion parenteral 3 " 9 . El progreso en los conocimientos relatives al metabolismo del cobre y sus requerimientos en diferentes situaciones no ha impedido que continual apareciendo publicaciones con casos cli'nicos de la deficiencia, como muestra de que el problema aun esta vigente 10 " 13 . La enfermedad cardi'aca producida por una situacion experimental de deficit de cobre ha sido caracterizada por hdpertrofia y palidez del