UNIPROT:P00750 - FACTA Search

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Query: UNIPROT:P00750 (PLA)
16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This paper describes a method for obtaining cultures of rat ventral prostate epithelial cells. The prostate is first perfused with a collagenase solution before removal from the animal; subsequent mincing and incubation in vitro produces a suspension of alveolar cell clumps. Upon incubation, these clumps attach to the surface of the culture dish and spread into discrete epithelial cell colonies, which both retain differentiated morphology, and secrete a species of plasminogen activator that is characteristic of prostatic tissue. These properties were not observed in cultures prepared from single cell suspensions of the same organ. Maintenance of epithelial colony integrity and secretory activity specifically required the continued presence of stromal cells, glucocorticoids and insulin. Androgenic steroids were much less effective than glucocorticoids in stimulating plasminogen activator secretion and in maintaining colony integrity, in spite of the well-established androgen dependence of prostatic tissue morphology in vivo and in organ culture. Furthermore, no effects of prolactin were observed, either when this hormone was tested alone or in conjunction with steroid hormones. Of 3 retinoids tested, retinal was highly cytotoxic at concentrations in the range of 1 microM, whereas retinol and retinoic acid were without detectable effect.
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PMID:The culture of hormone-dependent epithelial cells from the rat ventral prostate. 699 12

A group of 20 healthy volunteers [10 women, 10 men; median age 25 (20-33) years] were examined by means of pulsed wave Doppler echocardiography, blood sample analysis and psychological testing before and after listening to three different examples of music: a waltz by J. Strauss, a modern classic by H. W. Henze, and meditative music by R. Shankar. To assess small haemodynamic changes, mitral flow, which reflects left ventricular diastolic behaviour, was measured by Doppler ultrasound. Heart rate, arterial blood pressure and plasma concentrations of adrenocorticotropic hormone, cortisol, prolactin, adrenaline, noradrenaline, atrial natriuretic peptide (ANP) and tissue plasminogen activator (t-PA) were determined simultaneously. Transmitral flow profile is characterized by early E-wave and late atrial induced A-wave. Velocity-time integrals were measured and the atrial filling fraction was calculated. The mental state was measured by using a psychological score (Zerssen) with low values (minimum 0) for enthusiastic and high values (maximum 56) for depressive patterns. Music by J. Strauss resulted in an increase of atrial filling fraction (AFF; 29% vs 26%; P < 0.05) and ANP (63 pg.ml-1 vs 60 pg.ml-1; P < 0.05). The mental state was improved (Zerssen: 6.5 vs 11 points; P < 0.05). After the music of H. W. Henze prolactin values were lowered (7.7 ng.ml-1 vs 9.1 ng.ml-1; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immediate physiological responses of healthy volunteers to different types of music: cardiovascular, hormonal and mental changes. 782 31

We have demonstrated in this study that prolactin inhibits hCG-induced ovulation in PMSG-primed mice. At 18 h after the hormone treatment the number of ova in the oviducts was found to be 31.7 +/- 6.7 (mean +/- SE) in hCG treated group. The number was significantly decreased (19.7 +/- 4.9) when 100 micrograms of prolactin was injected simultaneously. The same effect of PRL on hCG induced ovulation could be also observed at 24 h after the hormone treatment; the values reached respectively to 32.3 +/- 10.8 and 20.3 +/- 5.4. Both in vivo and in vitro experiments further showed that the inhibition of the gonadotropin-induced ovulation by PRL is mediated through decreasing in the ovarian plasminogen activator activity.
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PMID:[Prolactin inhibits gonadotropin-induced increase in ovarian plasminogen activator activity and ovulation in mouse]. 814 75

This study was conducted to determine whether prolactin (PRL) suppresses gonadotrophin-induced ovulation and disturbs the co-ordinated gene expression of tissue type plasminogen activator (tPA) and plasminogen activator inhibitor type-1 (PAI-1) in rat ovary. Immature female rats were injected with 10 IU pregnant mare's serum gonadotrophin to stimulate follicle growth, and 48 h received different doses of prolactin followed by 7 IU human chorionic gonadotrophin (HCG). The oviducts were examined for the presence of ova, and the amounts of tPA and PAI-1 mRNA present in the ovary were measured at various times after the hormone treatment. PRL had no significant effect on ovarian weight but caused a dose-dependent decrease in ovulation number. In the control animals receiving HCG alone, 13.3 +/- 1.3 (mean +/- SEM) ova/oviduct were found; while in animals receiving HCG plus 50, 100 or 200 microg PRL, the ovulation number was dose-dependently suppressed by 53.6, 66.9 and 76% respectively at 18 h after treatment. PRL suppression of HCG-induced ovulation was time-dependent. By 24 h after treatment, the number of ova in the oviducts in HCG- and HCG plus PRL-treated groups was not significantly different. PRL also suppressed HCG-induced tPA gene expression in a dose- and time-dependent manner. At all time points examined, tPA mRNA content of whole ovaries and granulosa cells (GC) in PRL-treated groups was lower than in the HCG-treated controls. The activities of PAI-1 in ovarian extracellular fluid (OEF) and PAI-1 mRNA in the theca-interstitial cells (TI) in the PRL-treated groups were higher than in the HCG-treated controls. The highest stimulation by PRL of PAI-1 activity in OEF and of PAI-1 mRNA in TI was observed at 9 h and 6 h after HCG treatment respectively. The localization of tPA and PAI-1 antigens in the ovaries was consistent with changes in the mRNA and activity levels. These data suggest that PRL temporarily delays, but does not completely inhibit, HCG-induced ovulation, which may be caused by a suppression of PA-mediated proteolysis.
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PMID:Prolactin delays gonadotrophin-induced ovulation and down-regulates expression of plasminogen-activator system in ovary. 945 47

The present study was designed to investigate the effect of prolactin (PRL) on plasminogen activator inhibitor-I (PAI-I) and tissue type plasminogen activator (tPA) gene expression in eCG-primed granulosa cells in vitro. At 46 h after the hormone treatment, ovaries were removed, and granulosa cells were prepared for culture. Cells were incubated for various times in serum-free medium in the presence or absence of LH and PRL alone or in combination. tPA and PAI-I activities in the media were assayed by fibrin overlay and reverse fibrin autograph, respectively. Cytoplasmic RNA from granulosa cells was prepared using the NP-40 method and was assayed for PAI-I and tPA mRNA levels. We demonstrated the following. 1) PRL increased PAI-I mRNA production in cultured granulosa cells. Inclusion of LH with PRL had a synergistic effect on increasing PAI-I mRNA levels. After 48-h culture, 3-fold increases in PAI-I mRNA levels were seen with LH in combination with PRL as compared with PRL alone. The synergistic increase in PAI-I mRNA levels occurred in a dose- and time-dependent manner. 2) The increase in PAI-I mRNA synthesis by PRL alone, or by PRL in combination with LH, was well correlated with the changes in PAI-I activity and antigen levels in the conditioned media. 3) PRL in the culture also dramatically decreased LH-induced tPA mRNA and activity in a dose- and time-dependent fashion. The decrease in the tPA activity by PRL was also correlated with an increase in the amount of PA-PAI-I complexes in the cell-conditioned media. 4) In situ hybridization of tPA and PAI-I mRNAs in the cultured granulosa cells also showed that PRL was capable of enhancing PAI-I mRNA while diminishing tPA mRNA production induced by LH. This suggests that the dose- and time-dependent decrease in the gonadotropin-induced tPA activity in the culture by the presence of PRL may be due to decreasing tPA mRNA synthesis on one hand and to neutralization of the tPA activity by the increased PAI-I activity on the other.
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PMID:Prolactin regulation of tissue type plasminogen activator and plasminogen activator inhibitor type-I gene expression in eCG-primed rat granulosa cells in culture. 968 15

This study aims to investigate the mechanism by which prolactin and GH interact to maintain mammary epithelial cell function in the rat. IGF-I is an important survival factor for the mammary gland and we have demonstrated that the effects of GH and prolactin involve IGF-I. GH acts by increasing IGF-I whilst prolactin acts by inhibiting the expression of IGFBP-5 from the mammary epithelium. During mammary involution, when serum prolactin levels decline, IGFBP-5 expression is dramatically upregulated and it binds with high affinity to IGF-I preventing IGF-I interaction with the IGF-receptor and thus leading to epithelial cell apoptosis. We have identified a specific interaction of IGFBP-5 with alpha s2-casein. This milk protein has also been shown to bind plasminogen and its activator tissue-type plasminogen activator (tPA) leading to enhanced conversion of plasminogen to plasmin. Plasmin is an important initiator of re-modelling of the extracellular matrix during mammary involution. A potential interaction between the cell death and extracellular matrix remodelling is evident from the observation that IGFBP-5 binds to plasminogen activator inhibitor-I (PAI-1). We thus hypothesized that IGFBP-5 could activate cell death by sequestration of IGF-I and activate plasminogen cleavage by sequestering PAI-1. In support of this hypothesis we have shown that both prolactin and GH inhibit tPA activity and plasminogen activation in the involuting mammary gland. Our results suggest that GH and prolactin inhibit cell death and ECM remodelling via the IGF-axis and also indicate a novel role for the milk protein alpha s2-casein in this process. We have now established lines of transgenic mice expressing IGFBP-5 on the beta-lactoglobulin promoter to explore its function in greater detail.
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PMID:Insulin-like growth factor binding protein-5 (IGFBP-5) potentially regulates programmed cell death and plasminogen activation in the mammary gland. 1095 8

We have proposed that growth hormone (GH) and prolactin (PRL) interact to suppress apoptosis in the mammary gland. GH increases insulin-like growth factor-I (IGF-I) synthesis whereas PRL suppresses the production of insulin-like growth factor-binding protein-5 (IGFBP-5) in the epithelial cells, which would otherwise inhibit IGF-mediated cell survival. IGFBP-5 was present in milk from involuting glands at high concentrations (approximately 60 microg/ml) and had a high affinity (8.03 x 10(-10) M) for IGF-I, suggesting an inhibitory effect of IGFBP-5 in the mammary gland. IGFBP-5 was present in the micellar fraction of milk and binds specifically to alpha(s2)-casein. Since alpha(s2)-casein also binds plasminogen and tissue-type plasminogen activator (t-PA), resulting in the conversion of plasminogen to plasmin, and since IGFBP-5 binds to plasminogen activator inhibitor-1 (PAI-1), we investigated whether apoptosis and extracellular matrix (ECM) degradation might be coordinately controlled by GH and PRL possibly acting through IGFBP-5. Litters were removed from lactating rats to initiate involution. Plasminogen activation and t-PA activity were both increased dramatically after 48 h and GH and PRL suppressed this response. By contrast, 17beta-oestradiol, progesterone or corticosterone did not influence either process. An antiserum to IGF-I, which blocked systemic IGF-I effects, failed to inhibit the activation of plasminogen or the increase in t-PA, suggesting that paracrine effects of IGF-I may be more important. Teat-sealing, which led to the accumulation of milk without hormonal changes, also led to increases in plasminogen activation and t-PA activity, suggesting that locally produced factors (of which IGFBP-5 is one) are important in controlling ECM remodelling. We propose that GH and PRL inhibit apoptosis and ECM remodelling by a process that involves the control of IGF-I and PAI-1 availability by IGFBP-5, thus allowing these processes to be tightly coordinated.
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PMID:Hormonal control of plasmin and tissue-type plasminogen activator activity in rat milk during involution of the mammary gland. 1105 40

A Continuous Flow Electrophoresis System (CFES) was used on Space Shuttle flight STS-8 to separate specific secretory cells from suspensions of cultured primary human embryonic kidney cells and rat pituitary cells. The objectives were to isolate the subfractions of kidney cells that produce the largest amounts of urokinase (plasminogen activator), and to isolate the subfractions of rat pituitary cells that secrete growth hormone, prolactin, and other hormones. Kidney cells were separated into more than 32 fractions in each of two electrophoretic runs. Electrophoretic mobility distributions in flight experiments were spread more than the ground controls. Multiple assay methods confirmed that all cultured kidney cell fractions produced some urokinase, and five to six fractions produced significantly more urokinase than the other fractions. Several fractions also produced tissue plasminogen activator. The pituitary cells were separated into 48 fractions in each of the two electrophoretic runs, and the amounts of growth hormone (GH) and prolactin (PRL) released into the medium for each cell fraction were determined. Cell fractions were grouped into eight mobility classes and immunocytochemically assayed for the presence of GH, PRL, ACTH, LH, TSH, and FSH. The patterns of hormone distribution indicate that the specialized cells producing GH and PRL are isolatable due to the differences in electrophoretic mobilities.
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PMID:Electrophoretic separation of kidney and pituitary cells on STS-8. 1154 4

Schizophrenia may reflect a sensitization of dopaminergic (DA) function. Apomorphine (Apo), a DA receptor agonist, induces both sensitization and tolerance of DA function in rodents depending on dose intervals. We investigated sensitization and tolerance to Apo in healthy male volunteers. After a period of acclimatization to the experimental setting (Day 1) subjects were assigned randomly to two groups: Group A subjects received seven injections of placebo (physiological saline) (PLA) and Group B subjects received seven injections of Apo HCl (7 microg/kg sc) under double-blind conditions at 2 h intervals commencing at 0930 hours (Day 2) after an overnight fast. Twelve hours after the seventh injection, i.e. on Day 3, after an overnight fast all subjects received an injection of Apo. Serial samples of blood commencing at 0900 hours were drawn after the first and last injection in both groups for assay of growth hormone (GH), prolactin (PRL) and cortisol by radioimmunoassay; sleepiness was measured using the Analog Sleepiness Rating Scale and yawning recorded by video recorder. The GH response in Group B (N = 8) was (a) decreased after the eighth injection of Apo compared with the first injection of Apo (P = 0.03) and (b) decreased after the eighth injection of Apo compared with the first injection of Apo in Group A (N = 10) (P = 0.001). The number of yawns in Group B was significantly decreased after the eighth injection of Apo compared with the first injection of Apo (P = 0.042). PRL, cortisol and sleepiness were not significantly different between the first and eighth injection of Apo. Sensitization was not observed in any of the measures studied. These results are compatible with induction of acute tolerance of DA-mediated GH and yawning responses. The method used provides a safe pharmacological paradigm to examine plasticity of DA mechanisms in man. Results are discussed in the context of possible therapeutic implications for schizophrenia.
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PMID:Induction of tolerance of dopaminergic responses in man. 1850 87

We investigated content of prostaglandin (PG) E(2), a luteotropic eicosanoid, and phospholipase A(2) (PLA(2)) activity in two distinct states of rat corpora lutea of lactation (LCL). Rats subjected to forced weaning on day 0 postpartum (PP0) had a significant attenuation of progesterone synthesis and LCL weight on PP6 and/or PP3 compared with normally lactating rats. Repeated administration of prolactin (10 IU, twice daily) to weaned rats reversed impaired LCL function and structural development beyond the normal level of lactating animals. From PP3 to PP6, PGE(2) level in lactating LCL was increased while it was not altered in non-lactating LCL. In contrast, PLA(2) activity in the cytosol plus microsome fractions was decreased in lactating LCL and was up-regulated in non-lactating LCL as early as on PP3. This study provides the first evidence for differential regulation of PLA(2) activity and PGE(2) synthesis in activation and activation failure of postpartum CL in rats.
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PMID:Differential regulation of phospholipase A(2) activity and prostaglandin E(2) synthesis in activated and non-activated corpora lutea of lactation by the presence and absence of suckling stimulus in rats. 1961 58

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