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)

This study concerned the resolution of rat pituitary FSH utilizing chromatofocusing. Among the 11 components resolved and positively identified, ten had apparent isoelectric points (pI) between 3.1 and 5.1. Approximately 1% of pituitary FSH eluted at pH 9.4. Treatment with varying amounts of neuraminidase followed by refocusing generated FSH components of higher pI values. Treatment with other glycosidases did not alter the elution characteristics in chromatofocusing, while exclusion chromatography established an inverse relationship between apparent molecular weight and pI. Dose-response curves of various FSH components and of the reference preparation in the current radioimmunoassay system were parallel to each other. A study of their in-vitro bioactivity, utilizing granulosa cells which produce a plasminogen activator due to FSH in a dose-dependent manner, provided the following evidence: increased acidity of the components led to an increase of maximum response and an increase of the dose necessary for half-maximum response. Considering the observed alterations in the heterogeneity of FSH with changing physiological states of the animal, it is concluded that qualitative changes of the FSH molecule are perhaps involved in a modulatory role in the biopotencies of the hormone.
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PMID:Heterogeneity of rat FSH by chromatofocusing: studies on in-vitro bioactivity of pituitary FSH forms and effect of neuraminidase treatment. 392 42

Fibrinolytic activity in porcine follicular fluid and plasminogen activator production by porcine granulosa cells in response to gonadotropins is described. Fibrinolytic activity was determined using a solid phase assay in which 125I-fibrinogen was coupled to latex beads. Urokinase plus plasminogen served as the standard. Porcine follicular fluid contained protease inhibitors as evidenced by its ability to inhibit the activity of an urokinase-plasminogen standard. Removal of these inhibitors by acid precipitation revealed plasminogen-dependent and -independent fibrinolytic activity. Cultured granulosa cells produced plasminogen activator in amounts that increased over time. This pattern was most significant in cells stimulated by hCG. Cells incubated with hCG produced significantly more plasminogen activator when compared to those cells cultured in absence of gonadotropin. The enhancement was most marked during the second 48 hrs in culture (p = 0.032). FSH was found to have no stimulatory effect on plasminogen activator production by cultured porcine granulosa cells.
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PMID:Porcine granulosa cell production of plasminogen activator: disparity between the effects of hCG and pFSH. 393 84

Relaxin (Rlx) is shown in vitro to increase the release of plasminogen activator (PA) activity from granulosa cells obtained from 28-day-old rats after priming 48 h before with PMSG. Priming with PMSG was essential for the subsequent marked increase in PA by the addition of Rlx to these cells in vitro. Under the same conditions Rlx also increased the release of both total collagenase and total proteoglycanase activities but not of beta-glucuronidase activity. The total collagenase and proteoglycanase activities of control cells are made up of essentially equal amounts of their respective active and latent enzymes. Rlx stimulation increases the amounts of the respective active enzymes while the latent collagenase and proteoglycanase activities are unchanged or decreased, respectively. The enzyme beta-glucuronidase was not stimulated by Rlx and appears not to be involved in follicular proteoglycan degradation. Granulosa cells harvested from preantral follicles responded most to FSH by PA production whereas cells from antral follicles responded more to LH, reflecting the known changes in concentration of FSH and LH receptors on these cells. The release of PA is maximal by all four hormones studied (FSH, LH, prostaglandin E1, and Rlx) on granulosa cells harvested from rats 48 h after PMSG treatment and this suggests that the follicles at this time are a mixture of both preantral and antral stages. The PA response to FSH is lost by 60 h after PMSG at the same time that the response to prostaglandin E1 is maintained at the same level, whereas that to Rlx and LH, although still significantly higher than controls, were decreased. By 70 h after PMSG, postovulatory, the responses to all hormones studied were lost. Thus, the involvement of PA in ovarian connective tissue alterations appears to be greatest in the period of follicular antrum formation rather than just before ovulation. Rlx is one of a number of hormones involved in the sequence of events culminating in follicle connective tissue remodeling as shown by its action on the release of three intrafollicular enzymes.
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PMID:Relaxin increases the release of plasminogen activator, collagenase, and proteoglycanase from rat granulosa cells in vitro. 608 81

The role of FSH in the regulation of plasminogen activator production was studied in granulosa cells obtained from 23- to 25-day-old female rats. Cells cultured without FSH secreted a negligible amount of plasminogen activator. Purified ovine, rat, and human FSH produced dose-dependent increases in plasminogen activator production. This FSH effect was mimicked by analogs of cAMP, prostaglandin E2, and choleratoxin. Purified ovine LH and ovine PRL had no effect on plasminogen activator production by these immature granulosa cells. However, when these granulosa cells were treated in vitro or in vivo with FSH and then exposed to LH or PRL, the cells responded to LH in a dose-dependent manner with increased plasminogen activator production. These cells remained unresponsive to PRL. Similarly to FSH, in vitro pretreatment of the cells with choleratoxin or analogs of cAMP also induced responsiveness to LH with increased plasminogen activator production. This responsiveness to both FSH and LH with increased plasminogen activator production was also observed in granulosa cells obtained from rat preovulatory follicles. These studies demonstrate that: 1) FSH but not LH regulates plasminogen activator production by immature granulosa cells from preantral follicles; 2) Pretreatment of the undifferentiated granulosa cells with FSH, choleratoxin, or cAMP induced granulosa cell responsiveness to LH with increased plasminogen activator production; and 3) Granulosa cells obtained from preovulatory follicles respond to both FSH and LH with increased plasminogen activator secretion. These results suggest that with the LH surge at ovulation, plasminogen activator production in follicles is increased and may be important in follicular rupture.
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PMID:Gonadotropins regulate plasminogen activator production by rat granulosa cells. 629 87

The main emphasis of this paper is on the changes in function of granulosa cells as they undergo cytodifferentiation in follicles developing from the preantral to the antral stage, and on the hormones present in the milieu of gonadotrophins and steroids which are essential for these events to proceed normally. We found that FSH alone could induce aromatase activity in cultures of immature granulosa cells and that this effect could be duplicated by dibutyryl cyclic AMP. Incubation of cell sonicates under optimal conditions indicated that FSH acted on granulosa cells to increase the cellular concentration of active aromatase. Prior treatment with androgens augmented the FSH effect. Progesterone synthesis is another differentiated function which can be induced in culture by FSH alone and augmented in the presence of androgens. In assessing the enzymes involved in progesterone synthesis we found that cholesterol side-chain cleavage activity had similar hormonal requirements whereas 3 beta-hydroxysteroid dehydrogenase activity was stimulated by FSH alone. FSH also stimulates cyclic AMP binding activity in cultured granulosa cells during cytodifferentiation. These proteins represent another class of intracellular proteins, quite distinct from the steroidogenic enzymes, which increase as the granulosa cells mature. The ability of FSH to induce the appearance of LH and prolactin receptors, and stimulate the secretion of plasminogen activator and proteoglycans is reviewed. It is concluded that the appearance of steroidogenic enzymes and other intracellular proteins, cell-surface and secreted proteins as well as morphological maturation of granulosa cells require the presence of FSH. In the "turning-on" of some of these differentiated functions androgens play a permissive role. Having established events which occur during normal development of the follicle, we considered ways by which this overall process could be interrupted and fertility controlled. Here we describe the ways by which prolactin and LHRH interfere with the normal process of granulosa cell cytodifferentiation.
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PMID:Hormonal interactions in the control of granulosa cell differentiation. 631 Feb 32

We studied the effects of LHRH and a potent agonist on plasminogen activator production by granulosa cells obtained from immature rats. Both LHRH and the agonist produced a dose-related increase in plasminogen activator production. Concomitant addition of LHRH or its agonist together with FSH to the granulosa cell cultures enhanced the stimulatory effects of FSH on plasminogen activator production. These in vitro findings suggest that LHRH exerts a direct stimulatory effect on plasminogen activator secretion by rat granulosa cells which may explain the acute stimulating effects of LHRH and its agonist on ovulation in hypophysectomized rats.
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PMID:Luteinizing hormone releasing hormone stimulates plasminogen activator production by rat granulosa cells. 640 19

The release of plasminogen activator by rat granulosa cells in vitro has been shown to be dependent on the concentration of FSH, and it has thus been proposed as a good assay for this hormone. However, it has been recently claimed that relaxin was also able to trigger the release of plasminogen activator by the same cells. In order to check the specificity of the assay, we studied the behavior of a large number of hormones and we found that it was strictly specific for FSH activity.
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PMID:The release of plasminogen activator by rat granulosa cells is highly specific for FSH activity. 640 24

The abilities of LHRH and a potent LHRH agonist ([D-Ser-(But),6, des-Gly-NH210]LHRH ethylamide) inhibit FSH responses by rat granulosa cells and Sertoli cells in vitro have been compared. Granulosa cells isolated from 22- or 25-day-old diethylstilbestrol-primed rats and cultured under defined conditions for 48 h with NIH-FSH-S13 (300 ng/ml) or cholera toxin (0.1 microgram/ml) showed increased aromatase activity, as determined by the release of 3H2O from [1 beta-3H]testosterone. LHRH (10(-7) M) or th agonist (10(-8) M) added simultaneously with FSH or cholera toxin inhibited the effects on the release of 3H2O without influencing the protein content of the cell cultures. A smaller stimulation of 3H2O production occurred with (Bu)2cAMP (1.0 mM) plus 3-isobutyl-l-methylxanthine (0.1 mM), and this was partially suppressed in the presence of LHRH or the agonist. Parallel studies with Sertoli cells from 15- or 20-day-old rats demonstrated that culture under appropriate conditions with FSH, cholera toxin, or (Bu)2cAMP (0.5 mM) for 24 h caused an increase in cellular aromatase activity and enhanced secretion into the medium of plasminogen activator. However, no inhibition by LHRH (10(-7) or 10(-9) M) or the agonist (10(-6) or 10(-8) M) occurred when the peptides were added either simultaneously or 24 h before the stimulatory agent. Similarly, Sertoli cells from 11-day-old rats treated daily with LHRH agonist for 5 days in culture, showed no inhibition of aromatase activity after a 4-h stimulation with FSH or (Bu)2cAMP. FSH dose-response curves (0-300 ng/ml) for aromatase activity were shown to be similar after 5 days of culture with or without 10(-8) M LHRH agonist, indicating that the LHRH did not cause a shift in the sensitivity to FSH. The lack of inhibition was seen in Sertoli cell cultures maintained at 37 or 32 C. The enzyme digestion method used to isolated Sertoli cells was not responsible for the lack of effects of LHRH, since cell cultures prepared without the aid of proteolytic enzymes showed similar FSH stimulation of aromatase activity in the presence or absence of 10(-8) M agonist. Further, there was no evidence of degradation of the LHRH agonist when incubated with Sertoli cell cultures. From these studies, we conclude that 1) granulosa cells and Sertoli cells from immature rats differ in their responses to LHRH, and 2) the immature Sertoli cell is an unlikely target for a direct inhibiting influence of LHRH on spermatogenesis.
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PMID:Differential effects of luteinizing hormone-releasing hormone on follicle-stimulating hormone-dependent responses in rat granulosa cells and Sertoli cells in vitro. 678 Mar 24

Granulosa cells isolated from immature, DES-primed female rats were incubated in medium-199 plus 10% chicken serum with addition of FSH, or testosterone, or both. Cultures were incubated at 37 degree C for 7 days; medium samples were taken daily and analyzed for steroids and plasminogen-activator production. Only cultures containing FSH + testosterone produced significant amounts of both estradiol and progesterone after 2 days of incubation. The rate of estradiol production increased steadily up to the 4th day and then leveled off; the production of progesterone reached a maximum around the 3rd day, and then declined rapidly afterward. FSH alone was able to stimulate plasminogen activator production at the first day. Cultures with FSH + testosterone produced an additional peak of plasminogen activator activity at the 4th day. Plasminogen-activator production is thus not correlated with steroidogenesis in a simple way. We conclude that the granulosa cell require the presence of both FSH and testosterone at the beginning of incubation for normal response. Delayed addition of either hormone, or both, to the culture causes damage to the cells ability to produce normal responses to hormone treatment.
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PMID:Steroid and plasminogen activator production by cultured rat granulosa cells in response to hormone treatment. 678 52

Granulosa cells isolated from the ovaries of pregnant mare serum gonadotropin (PMSG)-treated immature rats were cultured with relaxin or FSH. Both hormones increased the secretion of plasminogen activator into the culture medium. Relaxin caused a dose-related rise in plasminogen activator but did not increase cAMP or progesterone levels in the medium of freshly harvested granulosa cells, although they were responsive to FSH. This ability of relaxin to stimulate plasminogen activator synthesis without progesterone or cAMP rises indicates that the pathways of post-receptor events leading to stimulation of plasminogen activator differ markedly from those of the gonadotropins. Relaxin is thus a fully characterized peptide hormone produced by the ovary with a well-defined action upon the granulosa cell and may have an intraovarian role in the events leading to ovulation.
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PMID:Relaxin stimulates plasminogen activator secretion by rat granulosa cells in vitro. 681 Dec 60


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