Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Extracts of rat anterior and intermediate-posterior pituitary were fractionated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and assayed for immunoactive ACTH and endorphin. In both lobes the major forms of immunoactive ACTH have apparent molecular weights of 31,000 (31K), 20--21K, 14K, and 4.5K, and the major forms of immunoactive endorphin have apparent molecular weights of 31K (coincident with the peak of immunoactive ACTH), 13K (a betaLPH-like peptide), and 3.5K (a beta-endorphin-like peptide). However, the quantitative distribution of immunoactivity among the various forms differs greatly between the lobes. Assays using an extreme COOH-terminal ACTH antiserum indicate that the 31K ACTH/endorphin molecule in rat anterior and intermediate pituitary is similar to the pro-ACTH/endorphin molecule from mouse pituitary tumor cells. A radioimmunoassay that is specific for the NH2-terminal non-ACTH, nonendorphin segment (referred to as 16K fragment) of the mouse pro-ACTH/endorphin molecule was used to assay extracts of rat pituitary. In addition to detecting material at 31K and 20--21K, the 16K fragment radioimmunoassay detects significant amounts of cross-reactive material with an apparent molecular weight of 16K in extracts of both lobes. This result also suggests that the structure and processing of the rat 31K ACTH/endorphin molecule is similar to that of mouse tumor cell pro-ACTH/endorphin. Cell suspensions were prepared from the anterior and intermediate lobes of the rat pituitary and maintained in culture for a 24-h period. The isolated cells from both lobes incorporate [3H] phenylalanine into immunoprecipitable ACTH- and endorphin-containing molecules. By sequential immunoprecipitation with ACTH and endorphin antisera, it is possible to demonstrate directly that a single molecule (31K ACTH/endorphin) has antigenic determinants for both ACTH and endorphin. Significant amounts of 31K ACTH/endorphin are released into the culture medium by isolated anterior lobe and intermediate lobe cells. The isolated intermediate lobe cells synthesize and secrete relatively large amounts of a beta-endorphin-like molecule; the isolated anterior lobe cells secrete significant amounts of both a betaLPH-like molecule and a beta-endorphin-like molecule. These same quantitative differences between anterior and intermediate lobe tissue were observed in immunoassays of extracts of the separated lobes and probably reflect differences in the processing of the common precursor. The isolated anterior lobe cells can be stimulated to release increased amounts of immunoprecipitable ACTH and endorphin by incubation with a cyclic AMP analog and a phosphodiesterase inhibitor.
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PMID:Existence of a common precursor to ACTH and endorphin in the anterior and intermediate lobes of the rat pituitary. 8 77

Denaturing solvents have been used to determine the molecular weight of the adrenocorticotropic hormone (ACTH) activity in mouse pituitary, in an ACTH secreting mouse pituitary tumor cell line (AtT-20/D-16v), and in the tissue culture medium from the pituitary tumor cells. ACTH activity was quantitated by radioimmunoassay and by bioassay. It is possible to utilize guanidine hydrochloride or sodium dodecyl sulfate in characterizing the multiple forms of ACTH because treatment of porcine ACTH (the 39 amino acid polypeptide form of ACTH, alpha(1-39)), pituitary extracts, tumor cell extracts, and tumor cell tissue culture medium with these denaturants does not diminish the immunological ACTH activity. Based on gel filtration in the presence of guanidine hydrocholoride, extracts of the pituitary tumor cells and the mouse pituitary contain three distinct molecular weight classes of ACTH activity. The major form of ACTH has a molecular weight similar to alpha(1-39) (molecular weight 4000-5500), but there are significant amounts of two higher molecular weight forms of ACTH: molecular weight 6500-9000 and molecular weight 20,000-30,000. The 6500-9000 molecular weight form of ACTH is the major form of ACTH in the tissue culture medium; there is no peak of alpha(1-39) size ACTH in the medium. In the radioimmunoasay all three forms of ACTH generate competitive binding curves parallel to that of porcine alpha(1-39); in the bioassay (stimulation of steroidogenesis in a mouse adrenal tumor cell line) the dose response curve for each of the molecular forms of ACTH is parallel to that for porcine alpha(1-39).
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PMID:High molecular weight forms of adrenocorticotropic hormone in the mouse pituitary and in a mouse pituitary tumor cell line. 16 85

The molecular weight of the adrenocorticotropic hormone (ACTH) activity in extracts of the separated anterior and intermediate-posterior lobes of the mouse pituitary was determined by gel filtration in guanidine-HCl. Following dilution or removal of the guanidine-HCl, ACTH activity was quantitated by both radioimmunoassay and bioassay. Extracts of the intermediate-posterior lobe contain approximately a tenth as much ACTH activity as extracts of the anterior lobe. In extracts of both the anterior and the intermediate-posterior lobes, about half of the immunological ACTH activity is similar in size to porcine ACTH (molecular weight 4000--5500). Two higher molecular weight forms of ACTH account for the remainder of the ACTH activity. About 40% of the immunological ACTH activity in anterior lobe extracts has a molecular weight of 6500--9000. Extracts of both the anterior lobe and the intermediate-posterior lobe contain ACTH activity with a molecular weight of 20,000--30,000. While this 20,000--30,000 molecular weight ACTH accounts for only 5% of the immunological ACTH activity in the anterior lobe extracts, it accounts for half of the immunological ACTH activity in extracts of the intermediate-posterior lobe. Extracts of an ACTH-secreting mouse pituitary tumor cell line (AtT-20/D-16v) contain the same three molecular weight forms of ACTH. Each of the three molecular weight forms of ACTH has a characteristic ratio of biological ACTH activity to immunological ACTH activity, independent of the source of the material (anterior lobe, intermediate-posterior lobe, or mouse pituitary tumor cell line).
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PMID:Molecular weights of adrenocorticotropic hormone in extracts of anterior and intermediate-posterior lobes of mouse pituitary. 17 67

A clonal cell strain F4C1 has been established from the transplantable rat pituitary tumor MtT/F4 and has been maintained in continuous culture for two years. The cells grow with a population doubling time of 48 hours; the karyotype with a modal number of 39 chromosomes includes a pair of large metacentric marker chromosomes. F4C1 cells in culture produce growth hormone and prolactin but not adrenocorticotropin in contrast to the MtT/F4 tumor which secretes all three hormones in the host rat. The cloned cells lack specific receptors for thyrotropin-releasing hormone and do not respond to this agent with increased prolactin or decreased growth hormone production. Treatment with hydrocortisone results in a small increase in growth hormone and a small decrease in prolactin production. Tumors generated in rats from injected F4C1 cells secrete prolactin and growth hormone but not adrenocorticotropin. The results suggest that growth hormone and prolactin are produced by a single cell type in the MtT/F4 tumor.
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PMID:Establishment in culture of a multihormone-secreting cell strain derived from the MtT/F4 rat pituitary tumor. 17 73

A double antibody immunoprecipitation technique using affinity-purified adrenocorticotropic hormone (ACTH) antiserum was employed to investigate the biosynthesis of ACTH in a mouse pituitary tumor cell line. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of cell extracts resolved four forms of ACTH with apparent molecular weights of 4,500, 13,000, 23,000, and 31,000. These four forms of ACTH can be detected by radioimmunoassay of cell extracts or by immunoprecipitation of cell extracts following incubation of cultures in [3H] tryptophan, [3H] lysine, or [3H] tyrosine. The double antibody immunoprecipitation scheme developed is specific, quantitative, and reproducible. ACTH biosynthesis was examined in both steady and pulse-labeling experiments using [8H] tyrosine or [3H] lysine. The results of these experiments are consistent with the proposal that Mr=31,000 ACTH is the biosynthetic precursor for all three smaller forms of ACTH and that Mr=23,000 ACTH is a biosynthetic intermediate. Both Mr=13,000 ACTH and Mr=4,500 ACTH are derived from the intracellular processing of Mr=31,000 ACTH.
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PMID:Biosynthesis of adrenocorticotropic hormone in mouse pituitary tumor cells. 18 15

Isoproterenol, corticotropin (ACTH), and triodothyronine immobilized on glass and Sepharose beads by diazotization procedures have been shown to interact with cultured tumor cells of "target tissue" origin. Cells used were rat glioma cells (C6), rat adrenal tumor cells (Y-1), and rat pituitary tumor cells (GH3). The rat glioma cells bound principally to immobilized isoproterenol, whereas the rat adrenal tumor cells bound to immobilized corticotropin, and rat pituitary tumor cells bound to immobilized triiodothyronine. Binding was inhibited by preincubation of the cells in soluble drug or hormone. With C6 cells there was a positive correlation between adenylate cyclase [ATP pyrophosphate-lyase (cyclizing, EC 4.6.1.1] stimulation and the degree of binding to the immobilized isoproterenol. Norepinephrine, bound through the ethanolamine side chain via an amide linkage, did not bind cells, demonstrating specific structural requirements for drug-cell interactions. HeLa cells were shown to bind tightly to diphtheria toxin coupled to Sepharose beads via an amide bond. This binding was inhibited by prior incubation of the Sepharose toxin with purified antitoxin. Toxin bound to Sepharose via an azo bond did not bind cells. These data suggest that the cell affinities are due to cell surface receptors interacting with the immobilized drugs and hormones, and that the observed affinities possibly reflect the relative receptor complement of these cells.
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PMID:Affinity isolation of cultured tumor cells by means of drugs and hormones covalently bound to glass and Sepharose beads. 18 May 34

Cerebrospinal fluid (CSF) concentrations of corticotropin, growth hormone, thyrotropin, prolactin, luteinizing hormone, and follicle stimulating hormone were measured in 28 patients with various neurologic disorders, in 49 patients with pituitary tumors of whom 22 had suprasellar extension, and in 6 patients with craniopharyngiomas. With the exception of 1 patient with pseudotumor cerebri, CSF adenohypophyseal hormone concentrations were low in patients with neurologic disease and in patients with pituitary tumor without suprasellar extension. In marked contrast, 21 to 22 patients with suprasellar extension of a pituitary tumor and 2 of 6 patients with a craniopharyngioma had elevations of one or more CSF adenohypophyseal hormones. Posttreatment CSF adenohypophyseal hormone levels fell from previously elevated levels in 4 of 5 patients. These data suggest that an elevated CSF adenohypophyseal hormone concentration is a sensitive indicator of suprasellar extension of a pituitary tumor, and posttreatment measurements are useful in determining efficacy of therapy.
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PMID:Cerebrospinal fluid hormone concentration in the evaluation of pituitary tumors. 18 Aug 61

Double-antibody immunoprecipitation procedures with antisera to endorphins and to corticotropin (ACTH) were used to study the biosynthesis of these peptides in a mouse pituitary tumor cell line. Cultures were incubated with a (3)H-labeled amino acid, and aliquots of culture medium were immunoprecipitated. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis of [(3)H]phenylalanine-labeled immunoprecipitates prepared with endorphin antisera resolved three forms of endorphin with apparent molecular weights of 31,000, 11,700, and 3500; immunoprecipitates prepared with the ACTH antiserum contained four forms of ACTH with apparent molecular weights of 31,000, 23,000, 13,000 and <4500. Sequential immunoprecipitation of culture medium with the ACTH antiserum and then with the endorphin antiserum (or the reverse order) indicated that both antisera precipitated the same 31,000 dalton molecule. Purified pools of the different forms of ACTH and endorphin were prepared by immunoprecipitation and gel filtration. The tryptic peptides found in [(3)H]phenylalanine- or [(3)H]tryptophan-labeled 31,000 dalton ACTH were identical to the tryptic peptides found in digests of 31,000 dalton endorphin labeled with the same amino acid. A tryptic peptide similar to the lipotropin tryptic peptide [betaLPH(61-69)] that contains the opiate-active methionine-enkephalin sequence could be identified in 31,000 dalton ACTH and in all the different forms of endorphin. Most of the peptide cleaved from 31,000 dalton ACTH when it is converted to 23,000 dalton ACTH could be precipitated by endorphin antisera; this 11,700 dalton endorphin molecule is similar to the pituitary hormone betaLPH in size and structure. The 3500 dalton endorphin is similar to beta-endorphin in size and structure. The culture medium from the AtT-20 mouse pituitary tumor cells contained approximately equimolar amounts of ACTH-related peptides and endorphin-related peptides.
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PMID:Common precursor to corticotropins and endorphins. 19 29

Raised levels of what appeared to be beta-lipotropin (beta-LPH), beta-melanotropic hormone, and beta-endorphin were detected by radioimmunoassay in the plasma of rats bearing the mammotropic transplantable pituitary tumor MtT-F4. The immunoreactivity to anti-beta-endorphin in the assay was displayed by a substance with the molecular weight of beta-LPH, as determined by gel filtration. Isolated cells of MtT-F4 tumor incubated in vitro released immunoreactive beta-LPH and beta-endorphin, with the expected molecular weights, into the incubation medium. These results suggest that the pituitary transplantable rat tumor MtT-F4 secretes peptides structurally related to beta-LPH.
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PMID:Immunoreactive beta-endorphin in the rat mammotropic transplantable tumor (MtT-F4). 20 51

Studies have been made with the mouse pituitary tumor cell line AtT-20 in culture to determine whether or not the suppression of pituitary corticotropin messenger RNA activity observed upon the administration of glucocorticoids to adrenalectomized rats is due to a direct action of these steroid hormones on the pituitary. The levels of corticotropin messenger RNA activity in AtT-20 cells treated with various steroid hormones were measured with the use of the cell-free protein-synthesizing system derived from wheat germ. The addition of dexamethasone to culture medium reduced the level of corticotropin messenger RNA activity to 30-40% of that in untreated cells. Corticosterone and cortisol exhibited a suppressive effect to a lesser extent. In contrast, nonglucocorticoids such as testosterone and 17beta-estradiol were essentially ineffective. These results indicate that at least part of the glucocorticoid action is exerted directly on the pituitary to suppress corticotropin messenger RNA activity.
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PMID:Effects of steroid hormones on the level of corticotropin messenger RNA activity in cultured mouse-pituitary-tumor cells. 20 19


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