Biomaterial Database

Effects of bromocriptine and tamoxifen on growth and hormone receptor levels of 7,12-dimethylbenz(a)anthracene-induced mammary tumors in rats. 1983

N Waseda, and Y Kato, and N Matsushita, and H Imura

The role of prolactin (PRL) and estrogen in the growth of 7,12-dimethylbenz(a)-anthracene (DMBA)-induced rat mammary tumors was investigated. Tumor growth was suppressed by both bromocriptine and tamoxifen. Combined administration of ovine PRL and tamoxifen attenuated the inhibitory action of tamoxifen on tumor growth. Serum PRL levels were decreased by both bromocriptine and tamoxifen administration. Estrogen receptors (ER) in tumor tissues were decreased in number by tamoxifen, but not by bromocriptine. Progesterone receptors (PgR) in DMBA-induced mammary tumors were abolished by tamoxifen and significantly reduced by bromocriptine. Combined administration of ovine PRL with tamoxifen attenuated the inhibition of PgR induced by tamoxifen alone, while ER remained undetectable. Specific PRL binding to the liver was significantly reduced by treatment with bromocriptine, tamoxifen and tamoxifen plus ovine PRL, whereas PRL receptors in mammary tumor were not influenced by these drugs. These results suggest that PRL may stimulate DMBA-induced tumor growth independently of ER and that a part of the inhibiting effect of tamoxifen on tumor growth may be explained by the decreased PRL secretion.

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
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
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
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
D011960	Receptors, Estrogen	Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important.	Estrogen Receptor,Estrogen Receptors,Estrogen Nuclear Receptor,Estrogen Receptor Type I,Estrogen Receptor Type II,Estrogen Receptors Type I,Estrogen Receptors Type II,Receptor, Estrogen Nuclear,Receptors, Estrogen, Type I,Receptors, Estrogen, Type II,Nuclear Receptor, Estrogen,Receptor, Estrogen
D011980	Receptors, Progesterone	Specific proteins found in or on cells of progesterone target tissues that specifically combine with progesterone. The cytosol progesterone-receptor complex then associates with the nucleic acids to initiate protein synthesis. There are two kinds of progesterone receptors, A and B. Both are induced by estrogen and have short half-lives.	Progesterone Receptors,Progestin Receptor,Progestin Receptors,Receptor, Progesterone,Receptors, Progestin,Progesterone Receptor,Receptor, Progestin
D011981	Receptors, Prolactin	Labile proteins on or in prolactin-sensitive cells that bind prolactin initiating the cells' physiological response to that hormone. Mammary casein synthesis is one of the responses. The receptors are also found in placenta, liver, testes, kidneys, ovaries, and other organs and bind and respond to certain other hormones and their analogs and antagonists. This receptor is related to the growth hormone receptor.	Prolactin Receptors,PRL Receptors,Prolactin Receptor,Receptors, PRL,Receptor, Prolactin
D001971	Bromocriptine	A semisynthetic ergotamine alkaloid that is a dopamine D2 agonist. It suppresses prolactin secretion.	2-Bromoergocryptine,Bromocryptin,2-Bromo-alpha-ergocryptine,2-Bromo-alpha-ergokryptine,2-Bromoergocryptine Mesylate,2-Bromoergocryptine Methanesulfonate,2-Bromoergokryptine,Bromocriptin,Bromocriptine Mesylate,CB-154,Parlodel,2 Bromo alpha ergocryptine,2 Bromo alpha ergokryptine,2 Bromoergocryptine,2 Bromoergocryptine Mesylate,2 Bromoergocryptine Methanesulfonate,2 Bromoergokryptine,CB 154,CB154,Mesylate, 2-Bromoergocryptine,Mesylate, Bromocriptine,Methanesulfonate, 2-Bromoergocryptine
D005260	Female		Females
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