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)

Adenylate cyclase activity in particulate fractions from a transplantable rat osteogenic sarcoma was stimulated in a dose-dependent manner by prostaglandins E1 and E2 (PGE1 and PGE2) and parathyroid hormone (PTH). Prostaglandin F2alpha was active at a high concentration (3 x 10(-4) mol/l). Pretreatment of membranes with collagenase plus hyaluronidase reduced the magnitude of the PTH effect but did not affect the size of the PGE1 effect. Guanosine 5'-triphosphate and its synthetic analogue 5'-guanylylimidodiphosphate (Gpp(NH)p) activated adenylate cyclase in particulate preparations from the osteogenic sarcoma. The latter agent produced much larger effects, although the concentrations required for half-maximal enzyme activation were the same for both agonists (approximately 2 x 10(-6) mol/l). The effects of PTH and Gpp(NH)p were supra-additive at some concentrations of hormone. The effects of PGE1 and Gpp(NH)p were supra-additive at all hormone concentrations tested. Pre-incubation of membrane particles for 6 min with PTH produced an enzyme activation which was not reversed by dilution through washing; pre-incubation with PGE1 did not produce this effect. The response of membrane adenylate cyclase to Gpp(NH)p (10(-4) mol/l) was 75% greater in preparations pre-incubated with PTH than in membranes pre-incubated in buffer alone or in buffer containing PGE1. The basal rate of cyclic AMP production in the adenylate cyclase assay system decreased over a 35 min incubation period. This decrease was prevented by addition of PTH or PGE1. Addition of NaF or Gpp(NH)p produced a steady increase in the rate of production of cyclic AMP with time. Membrane preparations did not reduce the biological activity of PTH and did not degrade 125I-labelled PTH. The results demonstrate that the PTH- and PGE-responsive adenylate cyclases of the osteogenic sarcoma have distinctly different properties and that particulate preparations of the tumour do not metabolize PTH.
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PMID:Membranes from a transplantable osteogenic sarcoma responsive to parathyroid hormone and prostaglandins: regulation of adenylate cyclase and of hormone metabolism. 27 36

The acute antigonadotrophic action of prostaglandin F2 alpha (PGF2 alpha) was examined in dispersed luteal cell preparations from immature superluteinized rat ovaries. Cell suspensions prepared by collagenase digestion and purification over a Percoll density gradient were incubated for 1 h in Eagle's minimum essential medium in the presence and/or absence of LH, PGF2 alpha, N6,O2'-dibutyryladenosine 3',5'-cyclic monophosphate (dbcAMP) and forskolin. Medium was assayed for total progesterone and adenosine 3',5'-cyclic monophosphate (cAMP). Luteal cell preparations showed typical steroidogenic (progesterone) responses to LH, mimicked by both dbcAMP and forskolin. Whilst the threshold LH dose to increase cAMP synthesis was greater than that for progesterone (100 micrograms/l compared with 1 microgram/l), 24 mumol forskolin/l was the threshold dose for both cAMP and progesterone responses. Furthermore, combined doses of LH and forskolin synergistically raised cAMP yet produced less than additive increases in progesterone. Similarly, combinations of dbcAMP plus forskolin produced less than additive progesterone increases. These data suggest that forskolin may not act as a simple mimic of LH. Prostaglandin F2 alpha dose-dependently inhibited forskolin-induced cAMP and progesterone synthesis and also inhibited progesterone synthesis induced by dbcAMP. These data suggest that the antigonadotrophic effect of PGF2 alpha has more than one locus of action, i.e. it both inhibits an adenylate cyclase event associated with cAMP generation and blunts the cellular response to cAMP. The present uncertainty over the exact locus of forskolin's action within the adenylate cyclase complex limits further delineation of the inhibitory action of PGF2 alpha on LH-responsive adenylate cyclase.
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PMID:Prostaglandin F2 alpha-induced functional luteolysis: interactions of LH, prostaglandin F2 alpha and forskolin in cyclic AMP and progesterone synthesis in isolated rat luteal cells. 302 26

Transport of alprostadil (prostaglandin E1) and dinoprost (prostaglandin F2 alpha) was studied in enzymatically dispersed normal and streptozocin-treated rat hepatocytes prepared by collagenase perfusion. Cell suspensions incubated at 37 degrees were sampled at time intervals for a period of 5 min and the supernatant analyzed for prostaglandins after centrifugation. The data analysis employed a theory and a model for solute transfer at the cell membrane-water interphase. Biophysical parameters such as the effective partition and the apparent permeability constants were used to define the transport mechanism. The apparent permeability coefficient of alprostadil and dinoprost transfer through normal hepatocytes was calculated to be 5 X 10(-3) and 3 X 10(-3) cm/sec with a mean partition coefficient of 1345 and 764 for both solutes, respectively. The permeability coefficient of alprostadil and dinoprost transfer through diabetic hepatocytes were 3 X 10(-3) and 2 X 10(-3) cm/sec with partition coefficient of 572 and 206, respectively. The results showed differences in prostaglandin transport between normal and diabetic hepatocytes, resulting from morphological and lipid alteration in the cytoplasmic membrane.
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PMID:Transport of prostaglandins through normal and diabetic rat hepatocytes. 657 77

A patch-clamp study of Ca2+ currents and spectrofluorometric detection of the intracellular Ca2+ concentration [Ca2+]i was performed on porcine myometrial cells that had been isolated by collagenase. Isolated myometrial cells were the typical long cylinder shape. The main length and diameter of myometrial cells were 505 +/- 20 and 11 +/- 0.5 microns (n = 40), respectively, in the prepartum period and 265 +/- 22 and 7 +/- 0.4 microns (n = 40), respectively, in the luteal phase. Immunocytochemistry with an antibody against desmin stained 90% of the cells positively, and about 95% of the cells excluded Trypan blue dye. The basal [Ca2+]i of myometrial cells in the luteal phase and the prepartum period was 119 +/- 12 (n = 30) and 154 +/- 31 nmol l-1 (n = 48), respectively. In prepartum myometrial cells, oxytocin (10(-7) mol l-1) and carbachol (10(-4) mol l-1) increased [Ca2+]i in a biphasic pattern, with a sharp peak followed by a plateau. In cells in the luteal phase, adrenaline (10(-7) mol l-1) plus propranolol (10(-6) mol l-1) produced a biphasic increase in [Ca2+]i. However, in the absence of propranolol, the increase in [Ca2+]i by adrenaline was small. Prostaglandin F2 alpha (10(-6) mol l-1) induced a monophasic increase in the [Ca2+]i in cells in the luteal phase. By depolarizing the cells from -30 to +50 mV from a holding potential of -50 mV, Ca2+ currents were evoked with a threshold at -20 mV, reaching a maximum between 10 and 30 mV.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of freshly dispersed porcine myometrial cells: evidence for voltage-dependent Ca2+ channels and regulatory receptors. 779 25

To investigate expression of monocyte chemoattractant protein-1 (MCP-1) in the ovine corpus luteum, a partial cDNA was produced by reverse transcription-polymerase chain reaction. This cDNA was 89% identical to that reported for bovine MCP-1 mRNA. In experiment 1, steady-state concentrations of mRNA encoding MCP-1 were measured in pools of luteal tissue collected on Days 3, 6, 9, 12, and 15 of the estrous cycle (estrus = O; n = 4/day). There were no differences in mRNA concentrations for MCP-1 among any of the days studied (p = 0.43). In experiment 2, midluteal-phase corpora lutea were collected from ewes at 0 (untreated), 2, 4, 8, and 16 h after administration of a luteolytic dose of prostaglandin F2alpha (PGF2alpha; n = 4/time point). Concentrations of MCP-1 mRNA were undetectable in untreated controls, were detectable at 2 h post-treatment, had increased 4 and 8 h after administration of PGF2alpha when compared to those at 2 h (p < 0.05), and were decreased 16 h after administration of PGF2alpha when compared to those at 4 h (p < 0.05). In situ hybridization for MCP-1 mRNA combined with immunocytochemical labeling of tissue inhibitor of metalloproteinase-1 (TIMP-1) in large luteal cells was used to determine whether the steroidogenic cells that have PGF2alpha receptors express MCP-1 mRNA in response to PGF2alpha. Messenger RNA encoding MCP-1 and TIMP-1 were not colocalized, indicating that MCP-1 was not expressed by large steroidogenic luteal cells during luteolysis.
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PMID:Messenger ribonucleic acid encoding monocyte chemoattractant protein-1 is expressed by the ovine corpus luteum in response to prostaglandin F2alpha. 947 38