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 determined that the primary reason for the frequently encountered poor survival of human scirrhous breast carcinomas in short-term (4 days) organ culture is mechanical injury to the tumor tissue during explant preparation. It was possible to minimize this injury by preparing 0.5-mm-thick slices using very sharp blades. This resulted in much improved preservation of tissue structure and function, as assessed by histology, DNA content, and enzyme synthesis and secretion. With the exception of insulin, which was always present in the culture medium, exogenous hormones, including estrogen, or serum did not further improve explant preservation. In rodent mammary tumors, growth in vivo and production of the serine protease plasminogen activator (PA) in organ culture are coordinately regulated by hormones, suggesting that PA may be a valuable indicator of tumor hormone responsiveness. We have now tested the effect of estrogen and other hormones on PA secretion in organ cultures of primary human breast carcinomas. We found that: modulation of PA by 17-beta-estradiol (10-8) M) occurred only in carcinomas which were positive for both estrogen and progesterone receptors; of 21 such tumors, 11 (52%) were responsive. Plasminogen activator was not modulated by estradiol in any of the 22 tumors which were negative for one or both receptors; hydrocortisone (10(-7) M) effectively inhibited, and 3,5,3'-L-triiodothyronine (10(-8) M) and adenylate cyclase activators effectively stimulated PA in most breast tumors, regardless of their estrogen and progesterone receptor status. Prolactin (5 micrograms/ml) had no effect when tested alone; urokinase-type PA was found to be the principal PA produced by human breast tumors. Changes in its rate of synthesis and secretion and not in the content of PA inhibitors appeared to be the prevailing mechanism of enzyme regulation by hormones. In summary, short-term organ culture coupled with the use of PA as an index of response appears to be a promising approach to the study of hormone sensitivity of primary human breast carcinomas.
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PMID:Hormonal modulation of plasminogen activator: an approach to prediction of human breast tumor responsiveness. 310 11

In a double-blind study we randomized insulin-dependent diabetics (n = 19) into a group (n = 12) given daily 250 mg Sorbinil, a potent aldose reductase inhibitor reported to ameliorate diabetic neuropathy, and another group (n = 7) given placebo for 1 year. Objective, neurophysiological variables (biothesiometry, electromyography, nyctometri) were followed throughout the study and correlated with fibrinolytic variables in blood. We found that Sorbinil did not improve any of the selected neurophysiological variables. Neither did Sorbinil induce marked changes in the fibrinolytic activities of the extrinsic, tissue-type plasminogen activator (t-PA), or in the intrinsic factor XII-dependent or factor XII-independent (urokinase-like) plasminogen activator systems. We found no effect of Sorbinil on the activity of the fast-reacting inhibitor (PA-I) of plasminogen activator. Levels of PA-I in plasma influence the amounts of t-PA precipitated in euglobulins.
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PMID:Neurophysiological variables and fibrinolysis in insulin-dependent diabetes treated with an aldose reductase inhibitor or placebo. A double-blind randomized study. 310 5

Low fibrinolytic activity, as measured by euglobulin (EFA), has been observed in obese subjects, and hypofibrinolysis may play a role in the pathogenesis of atherosclerosis and its complications. Blood fibrinolytic activity is regulated through a complex system of activators and inhibitors, especially plasminogen activator inhibitors (PA Inhibitors). In a group of 35 non-diabetic subjects with a wide range of body mass index (BMI), EFA was negatively correlated, and PA Inhibitor activity positively correlated, with BMI and plasma insulin levels. In a population of 49 non-diabetic obese women (differing from a control group of normal weight by lower EFA and higher level, of PA Inhibitor activity, plasma insulin and triglyceride), the PA Inhibitor activity was positively correlated with BMI, insulin and triglyceride. The increase in PA Inhibitor activity was associated with a high value of PA Inhibitor 1 antigen measured by an immuno-radiometric assay, indicating that the increased activity was due to a high level of circulating PA Inhibitor 1. Plasma insulin was lowered in obese non-diabetic subjects, without modification of the body weight, by a 24 hour fast or by treatment with Metformin. After 24 hours' fast, ten obese subjects had lower levels of insulin and PA Inhibitor activity and an increase in EFA. Treatment for 15 days by 1.75 g Metformin (or placebo), on a weight maintaining diet, induced, in the Metformin group, a decrease in plasma insulin, triglyceride and PA Inhibitor activity and an increase in EFA, while no change was observed in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relationships between plasma insulin triglyceride, body mass index, and plasminogen activator inhibitor 1. 311 43

Factor VIII (FVIII) and plasminogen activator activity (PAA) rise during hypoglycaemia, and this might contribute to the vascular complications of diabetes. Similar changes in haemostasis accompany raised plasma levels of vasopressin (aVP) and adrenaline. To investigate the effects of these hormones on haemostasis during hypoglycaemia and the role of plasma insulin concentrations, eight insulin-dependent diabetic patients underwent controlled hypoglycaemia for 20 min and 13 diabetic patients were investigated during hyperinsulinaemia with blood glucose maintained at 8.0 mmol/l. During hypoglycaemia, insulin levels increased to median values of 114 mU/l, a VP rose from 0.5 to 4.4 (p less than 0.005) pg/ml and adrenaline from 0.4 to 4.4 nmol/l (p less than 0.005). FVIII coagulant activity (FVIII:C) rose from 0.75 to 1.09 IU/ml (p less than 0.01) and the ristocetin co-factor (FVIIIR:Co) and von Willebrand factor antigen (vWF:Ag) showed similar responses. PAA increased from 156 to 745 units (p less than 0.005). During hyperinsulinaemia, insulin rose following infusion from 24 to 52 and 118 mU/l, maintained for an hour at each level. Despite this, plasma aVP, FVIII:C, FVIIIR:Co, vWF:Ag and PAA remained unchanged. This study indicates that the marked changes in FVIII, vWF and PAA concentrations which accompany hypoglycaemia depend on low blood glucose and not raised plasma insulin. The response in probably mediated by increases in adrenaline and aVP, which are part of the physiological response to hypoglycaemia.
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PMID:Hormonal control of haemostasis during hypoglycaemia in diabetes mellitus. 311 5

Haemostatic variables were assessed in 43 patients, 28 insulin-dependent and 15 non insulin-dependent. Maximum aggregation by low concentrations of adenosine diphosphate (ADP) or arachidonic acid and elevated plasma concentrations of TxB2, Factor VIII, vWF:Ag, RCoF and fibronectin (Fnct) indicated a hypercoagulable state. The manifestation of vasculopathy was associated with elevated concentrations of RCoF, Fnct, Hbalc, cholesterol and triglycerides, while impaired fibrinolysis was demonstrated by decreased t-PA levels and the absence of crosslinked fibrin degradation products (XL-FDP).
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PMID:Diabetes mellitus as a hypercoagulable state: its relationship with fibrin fragments and vascular damage. 311 98

The effects of insulin, somatomedin-C (Sm-C), epidermal growth factor (EGF), fibroblast growth factor (FGF), vitamin E, and retinoic acid on growth and function of immature cultured pig Sertoli cells were investigated. All these factors, except vitamin E, stimulated Sertoli cell DNA synthesis and proliferation. The mitogenic effects of insulin observed only at micromolar concentrations were similar to those induced by nanomolar concentrations of Sm-C or EGF, but significantly less than those induced by FGF. The effects of EGF and Sm-C were almost additive, whereas those of Sm-C and FGF were synergistic. After a 6-day treatment, FGF and retinoic acid induced a significant increase in the number of follicle-stimulating hormone (FSH) receptors per cell, and in FSH-induced cyclic adenosine 3',5'-monophosphate (cAMP) production. Sm-C, which alone had no effect on these two parameters, potentiated FGF action. Basal plasminogen activator activity was enhanced after the 6-day treatment with EGF plus insulin and, particularly, with FGF plus insulin. Similarly, the response of the latter group to FSH was significantly higher than in any other group of cells. FGF was also able to stimulate cell multiplication and enhanced the FSH receptor number of Sertoli cells isolated from 15- and 26-day-old rats. Thus, FGF is the most potent known mitogenic factor for cultured Sertoli cells, and it stimulates the phenotypic expression of these cells.
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PMID:In vitro regulation of pig Sertoli cell growth and function: effects of fibroblast growth factor and somatomedin-C. 311 82

Using primary culture in a chemically defined medium of somatic testicular cells from immature pig, we were able to demonstrate synthesis and secretion of Somatomedin-C/Insulin-Like Growth Factor 1 (Sm-C/IGF-1) by Sertoli cells, a process that is stimulated by Fibroblast Growth Factor (FGF). The presence of IGF type 1 receptor was demonstrated on Sertoli cells. Sm-C/IGF-1 stimulates and potentiates the effects of FGF on both cell multiplication and secretion of plasminogen activator. The presence of both IGF type 1 and insulin receptors was also documented on immature Leydig cells. Pre-incubation of immature Leydig cells for 48 hours with Sm-C/IGF-1 resulted in a dramatic dose-dependent increment of both the LH receptor number and steroidogenic response to LH as well as a clear stimulation of DNA synthesis. These data provide new important insights on the role played by Sm-C, a growth and differentiating factor, on the maturation of the male gonad endocrine function.
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PMID:Somatomedin-C/insulin-like growth factor 1: a differentiating factor of testicular function. 312 25

The fibrinolytic response to venous occlusion was assessed in 29 women with normal or complicated pregnancy, by measurements of total t-PA and free t-PA with specific ELISAs. The release of t-PA from the vessel wall was 11 +/- 9 ng/ml in non-pregnant women (mean +/- SD, n = 6) but was markedly reduced throughout pregnancy. Following venous occlusion, free t-PA increased by 12 +/- 11 ng/ml in non-pregnant women but remained below the detection limit of 2 ng/ml towards the end of pregnancy. A markedly reduced t-PA release with absence of free t-PA was also observed during late pregnancy in patients with insulin-dependent diabetes mellitus, intra-uterine growth retardation and pre-eclampsia. Plasma levels of fragment D-dimer of cross-linked fibrin were measured with a specific ELISA in 79 pregnant women. D-dimer levels were 129 +/- 36 ng/ml (mean +/- SD, n = 8) in non-pregnant women and increased to 400 +/- 170 ng/ml (n = 25) and 440 +/- 220 ng/ml (n = 22) during the second and third trimester of pregnancy respectively. Significantly higher levels than observed in uncomplicated third trimester pregnancies were found in 3 out of 6 diabetic and in 2 out of 7 pre-eclamptic women. It is concluded that the t-PA release after venous occlusion is significantly reduced during pregnancy. In addition, released t-PA is rapidly inhibited. The levels of fragment D-dimer increase during pregnancy, suggesting that, notwithstanding the marked impairment of the fibrinolytic response to venous occlusion, the fibrinolytic system remains functionally active.
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PMID:Fibrinolytic response to venous occlusion and fibrin fragment D-dimer levels in normal and complicated pregnancy. 344 23

The effects of insulin, the tumour promotor tetradecanoyl phorbol acetate (TPA), TSH and combinations of these factors on growth and DNA synthesis have been examined in the FRTL-5 cell strain and in sheep thyroid cells. In addition the regulation of the production by sheep thyroid cells of the insulin-like growth factors (IGF) by TSH and their possible autocrine roles have been investigated. We found that insulin and the IGF's stimulated DNA synthesis in both rat FRTL-5 cells and sheep cells. TPA also stimulated growth in both cell types, and its effects were additive to those of insulin. In the FRTL-5 cells, TPA was a less potent stimulator of growth than TSH, but the effects of TPA and TSH were not additive which may imply growth stimulation through a common pathway. In sheep cells TSH was not mitogenic and did not appear to activate protein kinase C, the receptor for TPA. Sheep cells, unlike FRTL-5 cells, were found to produce IGF-I and IGF-II, and their syntheses were regulated by TSH. Sheep cells were also found to produce IGF-binding proteins which may modulate the biologic effects of the IGF's. Sheep thyroid IGF binding proteins were found to copurify with urokinase-like plasminogen activator on immunoaffinity chromatography. The production of this serine protease has also been shown to be regulated by TSH.
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PMID:Role of non-TSH factors in thyroid cell growth. 347 6

Adult human skin fibroblasts were used as a model to study the effects of transforming growth factor beta (TGF beta) on the secreted plasminogen activator (PA) activity of cultured cells. TGF beta, at nanogram concentrations, enhanced the secretion of pro-PA from two fibroblast strains in a time- and dose-dependent manner. The induced enzymatic activity was inhibited by anti-urokinase antibodies and it co-migrated with purified urokinase in polyacrylamide gels. The secretion of PA activity was abolished when cycloheximide (0.1 microgram/ml) was added to the cultures. The activity was thus dependent on protein synthesis rather than just on direct activation of a plasminogen proactivator. TGF beta had only a slight mitogenic effect on the test cells. Epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and insulin were ineffective alone in inducing PA. Insulin, on the contrary, had an inhibitory effect on the TGF beta-induced PA activity. In addition to its effects on the secretion of PA, TGF beta enhanced the production of a proteinase inhibitor by these cells. The results suggest a role for TGF beta in the regulation of PA activity and pericellular proteolysis in fibroblastic cells.
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PMID:Transforming growth factor beta alters plasminogen activator activity in human skin fibroblasts. 351 51


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