Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Differences exist in the rates at which hormones are inactivated by, or dissociate from, their target tissues. The present studies examined the binding of biologically active TSH to thyroid slices and compared its characteristics to those of PGE. Canine thyroid slices were initally incubated with 5 mU/ML OF BOVINE TSH (TSH-Inital) for 15 min, washed and incubated in media free of hormone for 3 hr. At the conclusion of this second incubation period all slices were again washed. Some were then transferred to media containing 10-2M theophylline for a final 10 min incubation and subsequent measurement of cAMP and protein kinase, while others were transferred to media containing (l-14C)glucose without theophylline for a final 45 min incubation to assess glucose oxidation. Identically treated slices never exposed to TSH served as controls, while others were exposed to TSH only during the final 10 or 45 min incubation periods (TSH-Final). cAMP content determined after significantly increased in TSH-Initial (mean 2.98 plus or minus 0.36 (se) pmol/mg wet wt) compared to control (0.35 plus or minus 0.04), but was less than that in TSH-Final (5.76 plus or minus 0.51). This phenomenon was not unique to canine thyroid, since comparable results were noted in studies of human, bovine or porcine thyroid slices. The protein kinase activity ratio (-cAMP/+cAMP) and glucose oxidation of TSH-Initial were also significantly increased above control following the final 10 min or 45 min incubations respectively. Addition of trypsin to the 3 h incubation abolished the subsequent increase in cAMP in TSH-Initial, while addition of TSH antiserum appreciably reduced this increase. These results are consistent with the persistent binding of biologically active TSH to thyroid. By contrast, evidence of similar persistent binding of PGE1 to thyroid, glucagon to liver, or parathyroid hormone to renal cortex was lacking when assessed by an identical experimental procedure. Differences between the duration of interaction of TSH and PGE1 with thyroid may be dependent or a more gradual dissociation to tissue bound TSH, a more rapid inactivation of bound-PGE1, or both.
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PMID:Evidence for persistent binding of biologically active thyrotropin to thyroid in vitro. 16 69

The steroidogenic response to ACTH prostaglandin E2 (PGE2) was studied in cat adrenocortical cells dispersed with trypsin. The dose-response curves of both agents were qualitatively and quantitatively similar. Exposure to PGE2 or ACTH in the presence of labeled steroid precursor (acetate) resulted in the accumulation of comparable levels of steroid intermediates and end-product. Submaximal or maximal concentrations of ACTH and PGE-2 given simultaneously elicited a response which was no greater than that obtained with either stimulant alone. Although calcium was required for optimal PGE-2 stimulation of steroid production, this requirement with ACTH as the stimulant, but greater than with butyryl cyclic AMP. PGE-2-induced increase in the adrenal cyclic AMP was not statistically significant and was small in relation to that found with equipotent steroidogenic ACTH concentrations. The possible relationship between prostaglandins, cyclic AMP, and calcium in the action of ACTH is discussed.
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PMID:Evidence for a possible prostaglandin link in ACTH-induced steroidogenesis. 16 16

Prostaglandins biosynthesized from 3H-arachidonic acid by trypsin-dispersed cat adrenocortical cells were isolated by silicic acid and thin layer chromatography. PGE, PGF, and a third component with mobility properties indistinguishable from either PGA or PGB were identified both in cortical cell homogenates and incubation medium. Concentrations of ACTH (125-250 muU) which stimulate steroidogenesis enhanced the conversion of labeled precursor to all three of these prostaglandins. These findings provide further evidence for the proposal that prostaglandins function as a critical link in ACTH-induced steroidogenesis.
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PMID:ACTH-induced prostaglandin biosynthesis from 3H-arachidonic acid by adrenocortical cells. 17 81

Prostaglandin (PG) biosynthesis by trypsin-dispersed cat adrenocortical cells was studied by radioimmunoassay (RIA). Parallel assays of incubation media using PGF2alpha and PGF1alpha antisera established that PGF2alpha is the primary PGF released by feline cortical cells. Following the reduction of PGE to PGF with sodium borohydride (NaBH4) these same two antisera were also used to identify PGE2 as the primary PGE released. RIA using a PGE antiserum confirmed the presence of PGE in the incubation medium. Steroidogenic concentrations of ACTH (50-250muU) enhanced PGE and PGF release, and indomethacin suppressed the ACTH-facilitated release. These studies provide additional evidence for ACTH-induced PG synthesis by feline cortical cells, and support the hypothesis that PGs play some role in the steroidogenic action of ACTH.
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PMID:Radioimmunoassay measurement of ACTH-facilitated PGE2 and PGF2alpha release from isolated cat adrenocortical cells. 18 38

3'-(4-[2-(1-P-Chlorobenzoyl-5-methoxy-2-methyl-indol-3-yl-acetoxy)-ethyl]-piperazin-1-yl)propyl-4-benzamido-N,N-dipropyl-glutaramate(+/-)dimaleate (protacine, CR 604), a new non-steroidal compound active on experimental inflammation, in vitro inhibits prostaglandin synthesis from arachidonic acid and platelet aggregation. When administered p.o., it prevents ex vivo platelet aggregation and in vivo arachidonate-induced thrombosis in rabbits. The cAMP levels of rat leucocytes are significantly reduced after treatment in vivo with protacine, even under maximum PGE-mediated stimulation. These effects, the inhibition of the proteolytic activity of trypsin and the fibrinolytic properties evidenced on recalcified plasma clots, contribute to explain the anti-inflammatory activity of protacine.
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PMID:Studies on the mechanism of action of protacine (CR 604), a new non-steroidal anti-inflammatory agent. 22 25

Conditioned medium (CM) prepared from bone marrow (BM) or spleen (SPL) cells from mice injected with PGE2 in doses ranging from 0.0001 to 10 micrograms was found to contain an activity inhibitory to the proliferation of granulocyte-monocyte progenitor cells (CFU-GM). This activity was found in medium conditioned for 24 to 48 h, but was not present in medium conditioned for longer time intervals. BM cells from PGE2-treated mice incubated over a concentration range of 0.1 to 1.0 x 10(6) cells/ml and SPL cells over a range of 1.0 to 10 x 10(6) cells/ml produced CM with equivalent degrees of inhibition for CFU-GM proliferation. Titration of this activity revealed a significant inhibitory effect still present at a 1/256 dilution. Inhibitory activity was similar whether or not CM was prepared in the presence or absence of FCS. Inhibition of CFU-GM development was approximately equal in the presence of either PWM SPL CM or L cell CM as sources of CSF activity. Morphologic analysis of CFU-GM revealed an equivalent inhibition of monocyte, monocyte-neutrophil, and neutrophil CFU-GM by the PGE2-stimulated inhibitory activity. Equivalent picogram amounts of PGE were measured in CM derived from BM or SPL cells from either control or PGE2-treated mice, indicating a low probability that injected PGE2 was carried over in the CM and contributed to CFU-GM inhibition. Protease digestion of BM or SPL cell CM from PGE2-treated mice revealed a loss of inhibitory activity after trypsin, chymotrypsin, pronase, and neuraminidase treatment. Inhibitory activity was also ablated by heat treatment at 56 degrees C for 30 min and 100 degrees C for 5 min. Acrylamide-agarose gel filtration of BM CM revealed an active inhibitory fraction in the Mr range of 5.5 to 8.0 kDa. The results of the present study suggest that one of the mechanisms by which PGE2 exerts its in vivo myelopoietic inhibitory action may be by stimulating the production of an inhibitory factor or factors from BM and SPL cells.
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PMID:In vivo modulation of myelopoiesis by prostaglandin E2. IV. Prostaglandin E2 induction of myelopoietic inhibitory activity. 317 Nov 82

Stimulated human blood monocytes and alveolar macrophages are known to elaborate a soluble factor(s) that inhibits fibroblast proliferation by stimulating fibroblast prostaglandin (PG) production. However, the factor(s) mediating these effects has never been completely characterized and its relationship to known cytokines has never been fully defined. In this study, we demonstrate that this factor(s) is partially trypsin-sensitive, is between 16 and 24 kilodaltons molecular weight, and elutes between 0.13 and 0.25 M NaCl and 24 and 38% 1-propanol from anion exchange and reverse phase columns, respectively. In addition, we demonstrate that interleukin-1 (IL-1) and tumor necrosis factor (TNF) have similar patterns of elution and that the fibroblast growth-inhibiting and PGE-stimulating activities in monocyte and alveolar macrophage supernatants are partially reversed with neutralizing antibodies against IL-1-beta or TNF. However, this inhibition is not due to IL-1-beta or TNF, alone, because each has a mild stimulatory effect on fibroblast proliferation. In contrast, a dose-dependent inhibition of fibroblast proliferation is noted when fibroblasts are simultaneously exposed to recombinant IL-1 and TNF. This inhibition is reversed when fibroblast PG production is blocked and appears to result from IL-1 and TNF synergistically stimulating fibroblast PGE production. Thus, the PG-mediated inhibition of fibroblast proliferation caused by stimulated human mononuclear phagocytes is not the result of a single cytokine but is instead at least partly mediated by an interaction of IL-1 and TNF.
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PMID:Human alveolar macrophage and blood monocyte inhibition of fibroblast proliferation. Evidence for synergy between interleukin-1 and tumor necrosis factor. 326 85

The role of immune cell products in modulating connective tissue metabolism was investigated. Supernates of both unstimulated and phytohemagglutinin-stimulated human mononuclear cell cultures suppressed fibroblast proliferation (up to 90%) and concomintantly stimulated fibroblast prostaglandin E(PGE) synthesis (20- to 70-fold). The growth suppression was, at least in part, a secondary result of the increased fibroblast PGE synthesis; growth suppression (a) paralled the increased fibroblast PGE synthesis, (b) was reversed by addition of inhibitors of prostaglandin synthesis (indomethacin, meclofenamate, and eicostaetraynoic acid), and (c) was reproduced by addition of exogenous PGE2 to fibroblast cultures. The prostaglandin-stimulatory, growth-suppressive activity was a product of non-T-lymphocyte, adherent cells and was present within 6 h of mononuclear cell culture. The activity was heat (56 degrees C) and trypsin sensitive, nondialyzable, and appeared in the 12,000-20,000 mol wt fractions by Sephadex G-100 chromatography. The activity in supernates of mononuclear cell cultures was removed by incubation with fibroblasts but not by similar incubation with peripheral blood mononuclear cells. Mononuclear cells release a factor(s) which modulates fibroblast proliferation by altering prostaglandin metabolism.
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PMID:Mononuclear cell modulation of connective tissue function: suppression of fibroblast growth by stimulation of endogenous prostaglandin production. 735 93

Relaxant and contractile effects of the tethered ligand domain sequences of murine PAR-1, PAR-2, PAR-3 and PAR-4, and of the proteases thrombin and trypsin were examined in mouse isolated tracheal preparations. The epithelium- and cyclo-oxygenase-dependence of these effects and the potential modulatory effects of respiratory tract viral infection were also investigated. In carbachol-contracted preparations, trypsin, thrombin, and the tethered ligand domain sequences of murine PAR-1 (SFFLRN-NH(2)), PAR-2 (SLIGRL-NH(2)) and PAR-4 (GYPGKF-NH(2)), but not PAR-3 (SFNGGP-NH(2)), induced transient, relaxant responses that were abolished by the cyclo-oxygenase inhibitor indomethacin. Repeated administration of SFFLRN-NH(2), SLIGRL-NH(2) or GYPGKF-NH(2) (30 microM) was associated with markedly diminished relaxation responses (homologous desensitization), although there was no evidence of cross-desensitization between these peptides. The tethered ligand domain sequences for PAR-1 and PAR-4 induced a rapid, transient contractile response that preceded the relaxant response. Contractions were not inhibited by indomethacin and were not induced by either thrombin or trypsin. Influenza A virus infection did not significantly affect the responses induced by either the proteases or peptides. Furthermore, epithelial disruption caused by mechanical rubbing had no significant effect on responses to these PAR activators in preparations from either virus- or sham-infected mice. In summary, the proteases trypsin and thrombin, and peptide activators of PAR-1, PAR-2 and PAR-4 induced relaxant responses of mouse isolated tracheal smooth muscle preparations, which were mediated by a prostanoid, probably PGE(2). Interestingly, PAR-mediated relaxations were not significantly diminished following acute damage to the epithelium caused by mechanical rubbing and/or the respiratory tract viral pathogen, influenza A. British Journal of Pharmacology (2000) 129, 63 - 70.
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PMID:Modulation of airway smooth muscle tone by protease activated receptor-1,-2,-3 and -4 in trachea isolated from influenza A virus-infected mice. 1069 3

The amnion, a single layer of epithelial cells (EC) overlying layers of mesenchymal cells (MC) has been identified as a source of intrauterine prostaglandins (PG). The objectives of the present study were: (1) to establish a technique for the isolation and culture of pure amnion EC and MC preparations, (2) to characterize the cellular expression of PGHS-II and PGHS activity within these separated amnion cells and (3) to characterize the pattern of glucocorticoid stimulation of these separated amnion cells. Term gestation human amnion was collected after elective caesarean section or vaginal delivery. A trypsin digestion was used to isolate EC and a mechanical digestion and collagenase dispersion was used to isolate MC. Following 48 or 96 h in culture, cells were incubated for 24 h in the presence or absence of 1 microm arachidonic acid and treated with cortisol (F: 10-1000 nm) or 1 microm dexamethasone (DEX). Cell types were identified by immunohistochemistry (IHC). Immunoreactive PGHS-II (ir-PGHS-II) and glucocorticoid receptor (ir-GR) were localized by IHC. PGHS activity was measured as PGE(2)output determined by radioimmunoassay. Mean PGE(2)production by MC at 72 h was 22-fold greater (P<0.05) and at 120 h was 32-fold greater (P<0.03) than PGE(2)output by EC. Administration of arachidonic acid stimulated a 5.0-fold increase in PGE(2)output (P<0.0002) by EC after 72 h and a 3.6-fold increase (P<0.05) after 120 h but did not alter MC PGE(2)output. Despite exogenous substrate, EC PGE(2)output remained significantly less than PGE(2)output by MC. There was no difference in PG production by EC and MC with the onset of labour. Ir-GR expression was found in both EC and MC. F and/or DEX with and without arachidonic acid (AA) stimulated PGE(2)output by EC. Only DEX and not F increased PGE(2)output by MC. These data suggest that relatively pure EC and MC preparations can be established from amnion. PG output and its regulation appears to differ within these two amnion cell types, dependent upon (1) substrate availability and (2) the regulation of PGHS activity.
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PMID:The characterization of human amnion epithelial and mesenchymal cells: the cellular expression, activity and glucocorticoid regulation of prostaglandin output. 1083 75


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