Biomaterial Database

Prolactin receptors in mammary tumors of GR mice. 1977

M E Costlow, and M Sluyser, and P E Gallagher

Prolactin receptors have been identified in estrone-progesterone induced mammary tumors from GR mice. 125I-labeled ovine prolactin binding to tumor homogenates reached a steady state in 12 hours at 22 degrees and was specific for prolactin. Prolactin receptors were highest (16 fmoles/mg protein) in primary, hormone-dependent tumors and declined progressively in transplanted hormone-dependent and transplanted hormone-responsive tumors. In autonomous tumors, binding was approximately 5% of that found in primary tumors. Scatchard analysis of binding to selected tumors indicated that the observed decrease in bound hormone was due to a loss in the number of receptor sites; binding affinity was unaltered (kd approximately 1 X 10(-10) M). Since receptors for estrogen and progesterone as well as those for prolactin decline in a concerted manner with the transition to autonomy, autonomous growth may result from a loss of receptors or an increase in the relative proportion of autonomous cells present in the tumor.

UI	MeSH Term	Description	Entries
D008325	Mammary Neoplasms, Experimental	Experimentally induced mammary neoplasms in animals to provide a model for studying human BREAST NEOPLASMS.	Experimental Mammary Neoplasms,Neoplasms, Experimental Mammary,Experimental Mammary Neoplasm,Mammary Neoplasm, Experimental,Neoplasm, Experimental Mammary
D009368	Neoplasm Transplantation	Experimental transplantation of neoplasms in laboratory animals for research purposes.	Transplantation, Neoplasm,Neoplasm Transplantations,Transplantations, Neoplasm
D011374	Progesterone	The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.	Pregnenedione,Progesterone, (13 alpha,17 alpha)-(+-)-Isomer,Progesterone, (17 alpha)-Isomer,Progesterone, (9 beta,10 alpha)-Isomer
D011388	Prolactin	A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.	Lactogenic Hormone, Pituitary,Mammotropic Hormone, Pituitary,Mammotropin,PRL (Prolactin),Hormone, Pituitary Lactogenic,Hormone, Pituitary Mammotropic,Pituitary Lactogenic Hormone,Pituitary Mammotropic Hormone
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D004970	Estrone	An aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone, a major mammalian estrogen. It is converted from ANDROSTENEDIONE directly, or from TESTOSTERONE via ESTRADIOL. In humans, it is produced primarily by the cyclic ovaries, PLACENTA, and the ADIPOSE TISSUE of men and postmenopausal women.	Folliculin (Hormone),Estrone, (+-)-Isomer,Estrone, (8 alpha)-Isomer,Estrone, (9 beta)-Isomer,Estrovarin,Kestrone,Unigen,Wehgen
D005260	Female		Females
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia