Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The secretion of cortisol increases in awake dogs after small hemorrhage, with little or no change in plasma immunoreactive (IR) ACTH. To determined if IR-ACTH reflects bioactive (B) ACTH after hemorrhage, changes in B-ACTH and IR-ACTH were determined in awake dogs. Trained dogs were prepared with adrenal venous and femoral arterial and venous cannula. Experiments performed 48-96 h after surgery consisted of blood sampling from the adrenal vein and femoral artery before and after a 7.5-10 ml/kg hemorrhage done over 3 min. Cortisol was assayed by HPLC with UV detection, and adrenal secretory rates were calculated using adrenal blood flow. Arterial B-ACTH was assayed after extraction using rat adrenal cells dispersed with collagenase; corticosterone produced was assayed by HPLC-UV. Arterial IR-ACTH was assayed by RIA using antisera directed against ACTH-(1-24). Dogs in which hypotension occurred (change in mean arterial pressure, -31 +/- 3; n = 6) were compared to dogs in which mean arterial pressure did not change (change in mean arterial pressure, -6 +/- 2; n = 5). In the absence of hypotension, B-ACTH increased by 10 min after the onset of hemorrhage coincident with increased cortisol secretion, whereas IR-ACTH did not increase until 20 min. Resting IR-ACTH was greater than B-ACTH (11 +/- 1 vs. 2 +/- 1 pg/ml), but the peak response of B-ACTH was greater than that of IR-ACTH (13 +/- 4 vs. 8 +/- 3 pg/ml). In the presence of hypotension, B-ACTH increased by 4 min, and IR-ACTH and cortisol secretion increased by 8 min after the onset of hemorrhage. Resting IR-ACTH was greater than B-ACTH (27 +/- 5 vs. 6 +/- 1 pg/ml), and the peak response of B-ACTH was less than that of IR-ACTH (64 +/- 26 vs. 112 +/- 33 pg/ml). In dogs subjected to blood sampling without hemorrhage (n = 4), resting IR-ACTH was greater than B-ACTH (34 +/- 5 vs. 5 +/- 1 pg/ml), but there was no change in B-ACTH, IR-ACTH, or cortisol secretion. The results show that small hemorrhage elicits changes in B-ACTH that are dissociated in time and magnitude from changes in IR-ACTH, are coincident with changes in cortisol secretion, and are greater in dogs that fail to maintain arterial pressure. These data indicate that B-ACTH predicts more accurately the change in cortisol secretion than does IR-ACTH after small hemorrhage.
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PMID:Dissociation between changes in plasma bioactive and immunoreactive adrenocorticotropin after hemorrhage in awake dogs. 254 6

The effect of cortisol or adrenocorticotropic hormone (ACTH) on basal and gonadotropin-releasing hormone (GnRH)-induced secretion of luteinizing hormone (LH) was studied in vitro using dispersed pig pituitary cells. Pig pituitary cells were dispersed with collagenase and DNAase and then grown in McCoy's 5a medium containing 10% dextran charcoal-pretreated horse serum and 2.5% fetal calf serum for 3 days. Cells were preincubated with cortisol or ACTH before GnRH was added. When pituitary cells were incubated with 400 micrograms cortisol/ml medium for 6 h or longer, increase basal secretion of LH was observed. However, GnRH-induced LH release was reduced by cortisol. The degree of this reduction was dependent on cortisol, and a concentration of cortisol higher than 100 micrograms/ml was needed. Cortisol also inhibited the 17 beta-estradiol-induced increase in GnRH response. ACTH-(1-24), ACTH-(1-39), or porcine ACTH had no influence on GnRH-induced LH secretion. Our results show that cortisol can act directly on pig pituitary to inhibit both normal and estradiol-sensitized LH responsiveness to GnRH.
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PMID:Effect of cortisol or adrenocorticotropic hormone on luteinizing hormone secretion by pig pituitary cells in vitro. 282 56

Human recombinant interleukin-1 beta (rIL-1 beta) stimulated glycosaminoglycan (GAG) production in human synovial fibroblast cultures. A dose-dependent increase in GAG production was found, to a maximum of 500%. Increase was detected at doses as low as 1 pg/ml of rIL-1 beta, reached a maximum at 10-100 pg/ml, and was apparent 10 hours after addition of rIL-1 beta. Stimulation of GAG was always accompanied by increased accumulation of prostaglandin E (PGE) in culture media and by increased collagenase production in approximately one-half the experiments. Indomethacin (5 micrograms/ml) completely inhibited PGE stimulation by rIL-1 beta, but only partially inhibited that of GAG overproduction and had no effect on collagenase production. Hydrocortisone (2 micrograms/ml) inhibited stimulation of all 3 parameters. Stimulation of hyaluronate in synovial cultures prevailed over that of sulfated GAG, which occurred to a lesser extent. Our results support earlier suggestions that interleukin-1 is a major active mononuclear cell factor that is capable of inducing profound changes in connective tissue cell function.
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PMID:Human recombinant interleukin-1 beta stimulates glycosaminoglycan production in human synovial fibroblast cultures. 303 96

The effects of triamcinolone hexacetonide (TH) on the synthesis of collagen and noncollagen proteins were tested in mandibular condylar cartilage of newborn mice. Four-day-old ICR mice received a single i.p. injection of TH at doses ranging from 0.4 to 4.0 mg/kg body weight. Hydrocortisone, deoxycorticosterone, dexamethasone, and progesterone were administered at a dose of 4.0 mg/kg. Test animals and nontreated and vehicle-treated controls were sacrificed after 24, 48, and 72 hours and were processed for electron microscopy. Additional animals were injected with 5 microCi of 3H-proline 2 hours before sacrifice. The specimens were extracted with 5% TCA containing 1 mM proline followed by 5% TCA, acetone, and ether, homogenized and digested with purified bacterial collagenase, and the amounts of radioactivity in collagenase digestible (CDP) and noncollagen proteins (NCP) were determined. The present results revealed that triamcinolone led to a significant dose-dependent decrease in the protein content of the tissue that lasted for 3 days (12-14% at the dose of 4 mg/kg). The incorporation of 3H-proline into CDP was reduced by 39, 57, and 42% at 24, 48, and 72 hours, respectively whereas the incorporation into NCP was reduced by 20, 35, and 23%, respectively. When compared with other steroids, dexamethasone revealed a similar inhibitory effect, whereas hydrocortisone and deoxycorticosterone had no significant effect. Progesterone, on the other hand, showed a transient (24 hours) stimulatory effect on the synthesis of collagen synthesis (21%, P less than 0.05). Electron microscopy showed an atypical arrangement of collagen fibers and accumulation of large aggregates of collagen that filled the entire matrical space between cartilage cells.
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PMID:Triamcinolone impairs the synthesis of collagen and noncollagen proteins in condylar cartilage of newborn mice. 312 68

The effect of angiotensin II (ANG II) on the secretion of angiotensinogen was studied in isolated rat hepatocytes, obtained by the collagenase perfusion technique and Percoll-density gradient centrifugation, and in the isolated perfused rat liver. In isolated hepatocytes, steady state concentrations of about 1, 10 or 100 nM of ANG II during 90 min of preincubation resulted in a 5, 27 and 33% increase of angiotensinogen secreted during a subsequent 3 hour incubation period. Secretion rates during the last hour of incubation were increased by about 70% by the two higher ANG II concentrations, as compared to controls. Hydrocortisone also induced an increased secretion of angiotensinogen in hepatocytes. The effect of ANG II was prevented by saralasin, a competitive ANG II-antagonist and by actinomycin D. ANG II had no effect of the rate of albumin secretion and of total protein secretion. In the isolated perfused liver, ANG II induced a similar increase of angiotensinogen secretion, without affecting albumin and total protein secretion rates. These observations are consistent with the view that ANG II is participating in a feed back stimulation system of angiotensinogen synthesis and secretion in vivo.
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PMID:Induction of angiotensinogen synthesis and secretion by angiotensin II. 343 79

Insulinlike growth Factor I (IGF I), a growth hormone-dependent peptide or somatomedin, was studied for its effects on bone formation by examining the synthesis of DNA, collagen, and noncollagen protein in cultures of 21-d fetal rat calvaria. IGF I caused a dose-dependent stimulation of the incorporation of [3H]thymidine into DNA at concentrations of 0.1--100 nM; the effect appeared after 6 h, was maximal at 12 h, and was sustained for 96 h. IGF I also increased the bone DNA content, IGF I at 0.1--3 nM had a small stimulatory effect on the incorporation of [3H]proline into collagenase-digestible protein (CDP) whereas 30 nM IGF I caused a two- to threefold increment and had a maximal effect. A smaller effect on the labeling of noncollagen protein (NCP) was also observed. The effect of CDP and NCP appeared and was maximal after 12 h and was sustained for 96 h. IGF I increased the total collagen content of bones. The IGF I stimulatory effect on the incorporation of [3H]thymidine was seen in both the periosteum and periosteum-free calvarium, whereas that on the labeling of CDP was seen only in the central, osteoblastic-rich, non-periosteal bone. Histological sections showed a 10-fold increase in the mitotic index after Colcemid arrest in IGF I-treated bones, the mitoses were equally distributed in the periosteum and central portions of the calvarium. Insulin had a stimulatory effect on the incorporation of [3H]proline into CDP and NCP and 1 nM--1 microM similar to the effect of IGF I. In contrast, high insulin concentrations (0.1 and 1 microM) were required to increase the incorporation of [3H]thymidine, and insulin did not affect DNA content. Cortisol decreased the stimulatory effect of IGF I on DNA labeling but greatly enhanced the stimulatory effect of IGF I on the incorporation of [3H]proline into CDP. Triiodothyronine and parathyroid hormone increased the incorporation of [3H]thymidine and were additive to IGF I. Triiodothyronine did not affect the labeling of CDP, but parathyroid hormone inhibited it and opposed the effect of IGF I. These studies indicate that IGF I stimulates bone DNA, collagen, and NCP synthesis in vitro. IGF I and insulin have similar effects on bone collagen synthesis but IGF I stimulates the synthesis of DNA at physiological concentrations, and insulin does not.
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PMID:Effect of insulinlike growth factor I on DNA and protein synthesis in cultured rat calvaria. 625 49

Hydrocortisone and dexamethasone prevent the appearance of gelatinase in serum-free explant cultures of normal human skin. Hydrocortisone inhibits maximally at 10(-6) M and dexamethasone at 10(-8) M in culture medium. Glucocorticoids at these concentrations do not cause a generalized decrease in protein synthesis; thus the effect on gelatinase shows specificity. The reduction in gelatinase activity caused by dexamethasone can be overcome in the presence of dexamethasone 21-mesylate, a glucocorticoid antagonist that binds irreversibly to the cytoplasmic steroid receptor. These data suggest that the enzymes of collagen degradation, collagenase and gelatinase, may be coregulated.
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PMID:Regulation of gelatinase in human skin organ cultures by glucocorticoids. 630 1

Cartilage-derived factor (CDF), a peptide closely related to the somatomedins, was studied for its effects on bone formation by examining the synthesis of DNA, collagen, and noncollagen protein in 24-96 h cultures of 21-day fetal rat calvariae. After 24 h of treatment, CDF at concentrations of 0.3-30 micrograms/ml caused a dose-dependent stimulation of the incorporation of 3H-thymidine into DNA by 12-59%. The effect appeared and was maximal after 12 h, and was sustained for 96 h. CDF also increased the bone DNA content by 30-60%. After 24 h of treatment, CDF at 10-30 micrograms/ml had a small stimulatory effect on the incorporation of 3H-proline into collagenase-digestible protein (CDP) and noncollagen protein (NCP). The effect on the labeling of CDP and NCP was sustained for 96 h. Cortisol decreased the stimulatory effect of CDF on DNA labeling but cortisol and CDF had an additive effect on the incorporation of 3H-proline into CDP. The CDF stimulatory effect on the labeling of DNA, CDP, and NCP was seen in both the periosteum and periosteum-free calvaria. These studies indicate that CDF stimulates bone DNA, collagen, and noncollagen protein synthesis in vitro and may be a local regulator of bone growth.
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PMID:Effect of cartilage-derived factor on DNA and protein synthesis in cultured rat calvariae. 642 27

The effects of cortisol on bone formation are complex and may be modulated by the presence of periosteal cells or by factors released by the periosteal tissue. To test these possibilities, cortisol was examined for its effects on the incorporation of 3H-proline into collagenase-digestible protein (CDP) and noncollagen protein (NCP), on DNA synthesis and on alkaline phosphatase activity in intact and in the periosteum and nonperiosteal bone of dissected calvariae from 21-day-old fetal rats. After 24 h of treatment, cortisol increased the incorporation of 3H-proline into CDP in intact bones and in the nonperiosteal bone of calvariae dissected after the culture. Cortisol inhibited the incorporation of 3H-thymidine into calvarial DNA but it caused a small increase in nonperiosteal DNA content. Cortisol did not affect the incorporation of 3H-proline into CDP in calvariae dissected prior to the culture if the periosteum and nonperiosteal central bone were incubated separately; the stimulatory effect was observed only if the two tissues were cultured in the same vial and were in contact. In contrast, cortisol stimulated alkaline phosphatase activity in the central nonperiosteal bone of calvariae dissected before or after the culture. After 72-96 h of treatment, cortisol inhibited the labeling of CDP, NCP, and DNA and the DNA content in intact bones and in both periosteal and nonperiosteal central bone of calvariae dissected after the culture. In contrast, when the periosteum was removed before the incubation, these inhibitory effects were observed in the periosteum and not in the nonperiosteal bone.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of cortisol on periosteal and nonperiosteal collagen and DNA synthesis in cultured rat calvariae. 643 Apr 99

Normal rat or human serum causes a greater incorporation of 3H-proline into bone collagenase digestible protein (CDP) and noncollagen protein (NCP) than does serum from hypophysectomized animals or hypopituitary humans. In the present study, we have tested fibroblast growth factor (FGF), a peptide isolated from bovine pituitary glands that has been shown to stimulate RNA and DNA synthesis in various mesodermal cells, for its effects on cultured fetal rat calvaria. The major effect of FGF appeared to be a stimulation of periosteal fibroblastic cell proliferation. Incorporation of 3H-thymidine into DNA was increased at concentrations of 10--1000 ng/ml; the effect appeared after 12 hr, was sustained for 96 hr, and could not be ascribed to an effect on 3H-thymidine uptake. Total DNA content was increased and histologic sections showed an increase in the number of mitoses in periosteal fibroblasts after colemid arrest. These effects were accompanied by an increase in the uptake and incorporation of 3H-uridine, a decrease in the incorporation of labeled proline into CDP, and a small and variable increase in the incorporation of proline into NCP. Cortisol opposed the effects of FGF on 3H-thymidine and 3H-uridine incorporation. Insulin did not alter the effect of FGF on 3H-thymidine incorporation, but FGF decreased the stimulatory effect of insulin on the labeling of CDP. The effect of FGF on thymidine incorporation and collagen synthesis was not altered by indomethacin. The major effect of FGF in calvaria is to increase DNA synthesis and stimulate the proliferation of periosteal fibroblasts. It does not appear to be the pituitary-dependent factor in serum that stimulates 3H-proline incorporation into CDP and NCP in calvaria.
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PMID:Effect of fibroblast growth factor on cultured fetal rat calvaria. 698 32


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