Prolactin binding to 7,12-dimethylbenz(a)anthracene-induced mammary tumors and liver in diabetic rats.
Cancer Res
; 37(11): 4070-4, 1977 Nov.
Article
em En
| MEDLINE
| ID: mdl-409490
ABSTRACT
Growth rates of 7,12-dimethylbenz(a)anthracene-induced mammary tumors and the specific 125I-labeled prolactin binding to membrane fractions prepared from livers and tumors were studied in rats made diabetic by streptozotocin injection. Growth was inhibited in a majority of tumors and prolactin binding was reduced in both tumors and livers from diabetic animals. Prolactin binding to individual tumors varied over a wide range in both intact and diabetic animals. Scatchard analysis of binding data revealed that the apparent affinity of prolactin binding to liver and tumor membranes was similar (Ka approximately 3.0 X 10(9) M-1) and was not affected by diabetes. We suggest that the reduction in prolactin binding to tumors may render these tissues less responsive to prolactin and thereby explain, at least in part, the observed inhibition of tumor growth in diabetic rats. However, some tumors in diabetic animals regressed despite relatively high levels of prolactin binding activity. Therefore, additional factors most certainly play important roles in the mechanism(s) by which the growth of 7,12-dimethylbenz(a)anthracene-induced tumors is impaired in the diabetic rat.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prolactina
/
Diabetes Mellitus Experimental
/
Fígado
/
Neoplasias Mamárias Experimentais
Limite:
Animals
Idioma:
En
Revista:
Cancer Res
Ano de publicação:
1977
Tipo de documento:
Article