Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the possible role of the hypothalamic-pituitary system in the control of the release of plasminogen activator (PA) into peripheral blood of male rats. Plasminogen activator was measured by euglobulin lysis time. Desamino-D- arginine vasopressin (dDAVP) and adrenaline injected i.v. induced an increase in plasma PA as did electrical stimulation of the median eminence (ME), but dDAVP had no effect on plasma PA in hypophysectomized rats. The PA response to ME stimulation was similar in Brattleboro rats (deficient in vasopressin) and adrenalectomized Wistar rats compared with intact Wistar rats, but was abolished by section of the pituitary stalk and was negligible in hypophysectomized rats. The 41-residue corticotropin releasing factor (CRF) had no effect on PA release. Saline extracts of anterior pituitary gland from both normal Wistar and Brattleboro rats produced a dose-dependent increase in plasma PA when injected into normal Wistar rats. The activity of pituitary tissue was abolished by boiling, but not by di-isopropyl fluorophosphate which inactivates PA itself. Thus the anterior pituitary gland of the rat contains a heat-labile factor which stimulates the release of PA from peripheral stores into the circulation. This pituitary factor is released by a hypothalamic factor that is neither vasopressin nor CRF.
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PMID:A hypothalamic-pituitary system that stimulates the release of plasminogen activator in the rat. 653 43

Activated Factor B (Bb), the central serine esterase of the alternative pathway of complement activation, exhibits restricted substrate specificity in the complement system for C3 and C5. The results presented here indicate that Bb can cleave and activate plasminogen in an experimental system containing purified plasminogen and Bb; complement cellular intermediate bearing the Bb-enzyme; or cobra venom factor-stabilized Bb-enzyme (CVF,Bb). Cleavage of plasminogen by Factor Bb generated 2 disulfide-linked polypeptides with apparent m.w. of 64,000 and 25,000 to 32,000 (SDS-PAGE). Complement cellular intermediates containing the C3b, Bb-enzyme cleave 40 to 80% of 4.5 micrograms of 125I-labeled plasminogen during 30 min of incubation at 37 degrees C; native Factor B was inactive; and anti-Factor Blg inhibited by 100% the plasminogen cleavage mediated by complement cellular intermediates bearing the Bb-enzyme. Fibrinolytic activity was detected in plasminogen activator (PA) assays when purified plasminogen and 125I-labeled fibrin tubes were incubated with Bb, CVF, Bb, or complement cellular intermediates bearing the C3b,Bb-enzyme: 10 micrograms Bb released 40 to 65% of the 125I-fibrin released by 5 micrograms urokinase in 4 hr at 37 degrees C. Plasminogen activator activity of the C3b,Bb-enzyme was found to be regulated in serum. At dilutions of NHS 1:50, the PA-activity of 1.6 micrograms Bb was 100% inhibited, and at a 1:250 dilution, 50% inhibition was observed. This report describes a novel activity for the Bb-enzyme, which constitutes the C3/C5-convertase of the alternative pathway of complement activation.
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PMID:Activated factor B (Bb) of the alternative pathway of complement activation cleaves and activates plasminogen. 691 Nov 48