Effects of Time and Duration of Progesterone Administration on Mammary Tumours Induced by 7,12-Dimethylbenz(a)Anthracene in Sprague-Dawley Rats

A reduction in tumour yield was apparent when progesterone administration was begun 25 days before feeding 7,12-dimethylbenz(a)anthracene (DMBA). This effect was most obvious when the duration of hormone administration was brief. Continuation of progesterone for some time after feeding DMBA caused a...

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Detalles Bibliográficos
Autores principales: Jabara, Anne G., Toyne, P. H., Harcourt, Alison G.
Formato: Texto
Lenguaje:English
Publicado: Nature Publishing Group 1973
Materias:
Articles
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2008829/
https://www.ncbi.nlm.nih.gov/pubmed/4686179
Descripción
Sumario:A reduction in tumour yield was apparent when progesterone administration was begun 25 days before feeding 7,12-dimethylbenz(a)anthracene (DMBA). This effect was most obvious when the duration of hormone administration was brief. Continuation of progesterone for some time after feeding DMBA caused a progressive diminution of the inhibitory effect, and 135 days of continuous hormone treatment entirely abolished the effects of 25 days pretreatment with the hormone. In contrast, when progesterone injections were begun 2 days after feeding DMBA, there was a trend towards enhancement of tumour yield. Continuous hormone administration appeared more effective than shorter treatment regimens.

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