Biomaterial Database

Modulation of plasminogen activator in rodent mammary tumors by hormones and other effectors. 1983

R Mira-y-Lopez, and E Reich, and L Ossowski

The production of plasminogen activator (PA) and its regulation by hormones and other effectors were studied in organ cultures of primary rat and mouse mammary tumors. PA was quantitated using the radioiodinated fibrin plate method. The level of PA in tumor tissue was 10- to 100-fold higher than that in normal rat or mouse mammary glands; the rates of PA secretion were 10- to 1000-fold higher in the tumor cultures. PA production was stimulated by prolactin and pituitary extracts in N-nitrosomethylurea- and 7,12-dimethylbenz(a)anthracene-induced rat tumors but not in mammary tumor virus-induced mouse tumors; hydrocortisone inhibited PA production in all three tumor categories. Sex hormones and agents such as cholera toxin and retinoic acid effectively modulated enzyme production by some tumors. Three major points of interest emerge from our findings: (a) the pattern of tumor PA response to hormones differs qualitatively and quantitatively from that previously determined for the normal mammary; (b) the profile of responses of tumor PA and tumor growth to hormones shows numerous correlations suggesting that these two parameters may be coordinately regulated; (c) pituitary extracts contain an apparently novel factor that stimulates rat mammary tumor PA synthesis.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007770	L-Lactate Dehydrogenase	A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.	Lactate Dehydrogenase,Dehydrogenase, L-Lactate,Dehydrogenase, Lactate,L Lactate Dehydrogenase
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
D009924	Organ Culture Techniques	A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)	Organ Culture,Culture Technique, Organ,Culture Techniques, Organ,Organ Culture Technique,Organ Cultures
D010960	Plasminogen Activators	A heterogeneous group of proteolytic enzymes that convert PLASMINOGEN to FIBRINOLYSIN. They are concentrated in the lysosomes of most cells and in the vascular endothelium, particularly in the vessels of the microcirculation.	Extrinsic Plasminogen Activators,Plasminogen Activator,Uterine-Tissue Plasminogen Activator,Uterine Tissue Plasminogen Activator
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
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D002772	Cholera Toxin	An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.	Cholera Toxin A,Cholera Toxin B,Cholera Toxin Protomer A,Cholera Toxin Protomer B,Cholera Toxin Subunit A,Cholera Toxin Subunit B,Choleragen,Choleragenoid,Cholera Enterotoxin CT,Cholera Exotoxin,Cholera Toxin A Subunit,Cholera Toxin B Subunit,Procholeragenoid,Enterotoxin CT, Cholera,Exotoxin, Cholera,Toxin A, Cholera,Toxin B, Cholera,Toxin, Cholera
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA