Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Selected properties of [3H]prostaglandin (PG) E1 binding to collagenase dispersed bovine luteal cells were studied and compared with those observed in luteal plasma membranes. [3H]-PGE1 specific binding to a relatively homogeneous population of luteal cells was a rapid (K1 = 4.2 X 10(5) M-1 .sec-1), reversible (K-1 = 3.9 X 10(-3) sec-1), saturable and specific process at 38 degrees C. The binding was homogeneous with an apparent dissociation constant of 2.4 nM and 1.8 X 10(5) receptors per cell. The presence of increasing amounts of unlabeled PGs inhibited [3H]PGE1 binding in a dose-dependent manner. The potency order for this inhibition of binding was: PGE 2 greater than PGE1, (15S)-15-methyl-PGE2 methyl ester greater than PGF2alpha greater than PGF1alpha greater than other PGs, PGE, PGF metabolites and PGF analogs. Other than the homogeneous nature of [3H]PGE1 binding and the greater effectiveness of PGE2 compared to PGE1 in cells, the rest of the properties of [3H]PGE1 binding to cells were in excellent agreement with those observed in plasma membranes.
 ...
PMID:Selected properties of [3H]prostaglandin E1 binding to dispersed bovine luteal cells. 20 3

Corpora lutea were recovered from mares either 4 to 5 days or 12 to 13 days after ovulation. Mixed populations of luteal cells were prepared by collagenase digestion and were incubated for 24 h in the presence or absence of prostaglandin (PG) F-2 alpha (250 ng/ml). PGF-2 alpha significantly (P = 0.03) reduced progesterone secretion by cells from late diestrous corpora lutea and tended (P = 0.06) to reduce secretion by early diestrous cells. PGF-2 alpha had no significant effect on leukotriene B-4 (LTB-4) production by cells from early diestrous corpora lutea, but significantly (P = 0.03) increased LTB-4 production by late diestrous luteal cells. It seems possible that LTB-4 could play a role as an intermediary in the action of PGF-2 alpha in luteolysis in the mare.
 ...
PMID:Effect of prostaglandin F2 alpha on release of progesterone and leukotriene B-4 by cells from corpora lutea of mares. 185 May 34

Corpora lutea were collected from Holstein heifers on Days 10 and 12 of the oestrous cycle and the cells were dispersed with collagenase. The dispersed cells were separated into preparations of highly purified (90-99%) small (less than 20 microns) and large (greater than 25 microns) luteal cells by unit gravity sedimentation and fluorescence-activated cell sorting. Net progesterone accumulation by 1 x 10(5) small cells and 1 x 10(3) large cells during 2 and 4 h incubations, respectively, were measured after additions of LH, PGF-2 alpha, and phorbol esters, alone and in combination. Progesterone synthesis was increased (P less than 0.05) by phorbol dibutyrate (PBt2) or PGF-2 alpha (P less than 0.05) in small, but not in large, luteal cells (10.1 +/- 3.0 and 18.1 +/- 5.0 ng/10(5) cells for 0 and 50 nM-PBt2, and 19.9 +/- 3.2 and 44.2 +/- 9.3 ng/10(5) cells for 0 and 1 microgram PGF-2 alpha/ml). The previously reported stimulatory effects of PKC activation and PGF-2 alpha addition to total dispersed cell preparations are therefore entirely attributable to the small, theca-derived cells. Small cells responded to low levels of LH (9.1 +/- 1.1, 69.0 +/- 5.4 and 154.7 +/- 41.4 ng/10(5) cells for 0, 1 and 5 ng LH/ml, respectively, P less than 0.05), while large cells responded only to high levels of LH (1635 +/- 318, 2662 +/- 459 and 3386 +/- 335 pg/10(3) cells for 0, 100 and 1000 ng LH/ml, respectively, P less than 0.05). PGF-2 alpha inhibited LH-, 8-Br-cAMP- and forskolin-stimulated progesterone synthesis in the large cells (3052 +/- 380, 3498 +/- 418, 3202 +/- 391 pg/10(3) cells for 1 microgram LH/ml, and 0.5 mM-8-Br-cAMP, and 1 microM-forskolin respectively and 1750 +/- 487, 2255 +/- 468, 2165 +/- 442 pg/10(3) cells for PGF-2 alpha + LH, PGF-2 alpha + 8-Br-cAMP and PGF-2 alpha + forskolin, respectively), indicating that the inhibitory effect of PGF-2 alpha on progesterone synthesis in large cells occurs at a site distal to cAMP generation. These results suggest that the large cells are the targets of the luteolytic effects of PGF-2 alpha, while the small cells are responsible for the previously reported luteotrophic effect of PGF-2 alpha in vitro.
 ...
PMID:Control of progesterone production in small and large bovine luteal cells separated by flow cytometry. 316 3

Corpora lutea from cyclic ewes were dissociated by collagenase and trypsin/EGTA treatments, and enriched fractions of small and large luteal cells were prepared on gradients of Ficoll. These fractions were incubated separately or remixed before incubation. Colchicine, cytochalasin B and the calcium channel-blocker verapamil significantly reduced progesterone production by both small and large luteal cell fractions, while isoprenaline stimulated an increase in progesterone production by large luteal cell fractions only. When fractions of small and large luteal cells were remixed, no more and no less progesterone was produced than would have been predicted from equivalent fractions incubated separately. There was therefore no evidence of synergism between small and large luteal cells in the production of progesterone. Prostaglandin F-2 alpha, which can inhibit LH-stimulated progesterone production by ovine luteal tissue in vitro, had no effect on LH-stimulated progesterone production by small luteal cell fractions, but significantly inhibited that by enriched fractions of large luteal cells. Since large luteal cell fractions were contaminated with small luteal cells, which are probably responsible for the progesterone-secretory response of these fractions to LH, it was concluded that the inhibition of LH-stimulated progesterone production by small luteal cells is dependent on the presence of large luteal cells. Oxytocin added to large and small luteal cell fractions did not affect progesterone production by either fraction. It was therefore concluded that the inhibitory action of PGF-2 alpha on LH-stimulated progesterone production may require the interaction of large and small luteal cells, but that oxytocin is not likely to be an intermediary in this interaction.
 ...
PMID:Do small and large luteal cells of the sheep interact in the production of progesterone? 386 69

Human endometrial cells were dispersed with collagenase and maintained in culture overnight. The synthesis of PGF by the dispersed cells incubated at 37 degrees C in serum-free medium was stimulated by estradiol (10(-7)M - 10(-5)M), histamine (5X10(-7)M - 5X10(-5)M), bradykinin (10(-6)M), phorbol myristate (PMA, 3X10(-8)M) and arachidonate (5X10(-6)M). Preincubation of the cells for 3 h with cortisol (5X10(-7)M - 5X10(-5)M), progesterone (10(-6)M) or mepacrine (10(-6)M - 2X10(-4)M) inhibited the response to histamine, bradykinin and PMA but not to arachidonate. Perfusion of the cultured cells in filtration chambers yielded similar results to those obtained in the incubation system but differences in the onset and duration of the responses to stimuli were found. In the perifusion system the responses to histamine and bradykinin were rapid and of short duration (peak response in less than 60 min) while the responses to PMA and arachidonate were of longer duration with a slower onset. We conclude that these observations using dispersed endometrial cells are consistent with previous work showing that histamine, bradykinin and PMA act by stimulating acylhydrolase activity, thereby liberating precursors such as arachidonic acid which are converted to prostaglandins by the cyclo-oxygenase complex.
 ...
PMID:Synthesis of prostaglandin F by cultured human endometrial cells. 643 82

Prostaglandin (PG) E and F output was studied in collagenase-dispersed amnion cells to determine the effect of extracellular Ca2+ upon PG synthesis. In the presence of 2.5 mM CaCl2, PGE and PGF output (picograms per 10(5) cells per 3 h) by cells obtained at term prior to labour following elective cesarean section (CS) was 183 +/- 39 and 127 +/- 23, respectively. This increased to 435 +/- 111 (p less than 0.025) and 241 +/- 49 (p = 0.056) from cells obtained after spontaneous labour and delivery at term (SL). Exclusion of CaCl2 from the medium (plus 0.1 mM EGTA) significantly reduced (p less than 0.025) PGE output in CS and SL cells (83 +/- 22 and 183 +/- 47, respectively) and PGF output in CS cells (70 +/- 17). PGE output in both CS and SL cells was unchanged when CaCl2 concentrations in the medium were decreased from 2.5 to 0.25 mM, but significantly attenuated (p less than 0.01) when extracellular CaCl2 was decreased from 0.25 to 0 mM. The voltage-sensitive Ca2+ channel blocker, D-600, decreased PGE output in the presence of (2.5 mM) CaCl2 to levels observed in the absence of CaCl2. Ionophore A23187 restored PGE output in the presence of D-600 and Ca2+. PGE output from CS amnion cells was stimulated by A23187 and elevated extracellular K+ (40 mM). In each case, exclusion of CaCl2 from the medium eliminated the response. These results suggest that PG output by human amnion is dependent, in part, upon the presence of extracellular Ca2+ and that Ca2+ may enter the cell via a potential-sensitive mechanism.
 ...
PMID:Prostaglandin synthesis by human amnion is dependent upon extracellular calcium. 664 Apr 32

Suspensions of luteal cells were prepared by collagenase dispersion of guinea-pig corpora lutea obtained at specific times during the oestrous cycle. Luteal cells incubated with hCG produced increased amounts of progesterone. For Days 3--13 of the oestrous cycle, the concentrations of hCG required for 50% of the maximum response were within the range, 1 x 10(-3) to 7 x 10(-3) i.u./ml, showing no marked loss of sensitivity to hCG with increasing luteal age. PGF-2 alpha (1 mumol/l), had no effect on basal production of progesterone but significantly inhibited hCG-stimulated progesterone production by luteal cells isolated on Days 7, 9, 10, 12 and 13 of the cycle. This concentration of PGF-2 alpha had no significant effect on progesterone production by luteal cells prepared earlier in the cycle (Days 3 and 5). It is concluded that (a) the luteolytic action of PGF-2 alpha in the guinea-pig is mediated, at least in part, by direct action on luteal cells, and (b) the cells from newly formed corpora lutea are resistant to the direct inhibitory action of PGF-2 alpha.
 ...
PMID:Inhibitory effect of PGF-2 alpha on hCG-stimulated progesterone production in vitro by luteal cells from guinea-pigs at different stages of the oestrous cycle. 695 31

The objective of this study was to measure and compare the concentrations of PGF 2 alpha receptors on luteal cells taken from cycling, pregnant, and pseudopregnant pigs. Corpora lutea were removed surgically from cycling, pregnant, and pseudopregnant (induced with 5 mg estradiol valerate/day i.m. beginning on Day 11) pigs on Days 12, 13, and 14 (postestrus) and were subjected to collagenase dissociation. Dissociated luteal cells (approximately 100,000 large viable cells per tube) were assayed for specific PGF 2 alpha binding by Scatchard analysis, using [3H]PGF 2 alpha and varying doses (0-5 microM) of unlabeled PGF 2 alpha. Luteal cells from all three types of pigs were shown to possess two specific PGF 2 alpha binding sites (high affinity, Kd = 9-47 nM; low affinity, Kd = 243-1359 nM). The concentrations of the high-affinity PGF 2 alpha binding site (PGF 2 alpha "receptor") on Days 12 and 13 were not significantly different (NS) between cycling (1.7 and 1.1 x 10(6) receptors per large luteal cell, respectively), pregnant (1.3 and 1.2 x 10(6)), and pseudopregnant (1.1 and 0.8 x 10(6)) pigs. However, on Day 14, luteal PGF 2 alpha receptor concentrations were significantly higher (p < 0.05) in cycling (4.2 x 10(6)) compared with pregnant (1.3 x 10(6)) and pseudopregnant (1.4 x 10(6)) pigs. We speculate that reduced luteal PGF 2 alpha receptor concentrations on Day 14 in pregnant and pseudopregnant compared with cycling pigs may lead to decreased luteal sensitivity to PGF 2 alpha in these animals, and that this mechanism may play a role in the maternal recognition of pregnancy in this species.
 ...
PMID:Prostaglandin F2 alpha receptor concentrations in corpora lutea of cycling, pregnant, and pseudopregnant pigs. 839 55

Although contractile interstitial cells (CIC) in the alveolar septum have been suggested to be involved in hypoxic pulmonary vasoconstriction (HPV), direct demonstration of cellular contraction under hypoxia has been lacking. To achieve this, we purified CIC from collagenase-dissociated bovine lung cells and examined the response of these cells to hypoxia. Prostaglandin (PG) F synthase served as a marker of CIC, and the isolated PGF synthase-positive cells were shown to preserve the ultrastructural features characteristic of CIC, most notably bundles of microfilaments. Isolated CIC seeded onto collagen gel disks became embedded and formed a lattice network with collagen fibrils. Exposure of these CIC-bearing gels to hypoxia (PO2 = 20-40 Torr) evoked a reversible reduction in gel volume, as assessed by measuring the surface area of the gel disks photographically. Thus CIC were shown to contract under hypoxia, providing the supportive evidence for the involvement of CIC in HPV.
 ...
PMID:Hypoxic contraction of contractile interstitial cells isolated from bovine lung. 876 21

Cellular interactions mediated by both contact-dependent and contact-independent mechanisms are probably important to maintain luteal function. The present studies were performed to evaluate the effects of luteotropic and luteolytic hormones, and also intracellular regulators, on contact-dependent gap junctional intercellular communication (GJIC) of bovine luteal cells from several stages of luteal development. Bovine corpora lutea (CL) from the early, mid and late luteal phases of the estrous cycle were dispersed with collagenase and incubated with no treatment, LH, PGF or LH + PGF (Experiment 1), or with no treatment, or agonists or antagonists of protein kinase C (TPA or H-7) or calcium (A23187 or EGTA; Experiment 2). After incubation, media were collected for determination of progester-one concentrations. Then the rate of GJIC was evaluated for small luteal cells in contact with small luteal cells, and large luteal cells in contact with small luteal cells by using the fluorescence recovery after photobleaching technique and laser cytometry. Luteal cells from each stage of the estrous cycle exhibited GJIC, but the rate of GJIC was least (P < 0.05) for luteal cells from the late luteal phase. LH increased (P < 0.05) GJIC between small luteal cells from the mid and late but not the early luteal phase. PGF increased (P < 0.05) GJIC between small luteal cells from the mid luteal phase and diminished (P < 0.05) LH-stimulatory effects on GJIC between small luteal cells from the late luteal phase. Throughout the estrous cycle, TPA decreased (P < 0.05) the rate of GJIC between large and small, and between small luteal cells, and A23187 decreased (P < 0.05) the rate of GJIC between large and small luteal cells. LH and LH + PGF, but not PGF alone increased (P < 0.05) progesterone secretion by luteal cells from the mid and late luteal phases. Agonists or antagonists of PKC or calcium did not affect progesterone secretion by luteal cells. These data demonstrate that both luteal cell types communicate with small luteal cells, and the rate of communication depends on the stage of luteal development. LH and PGF affect GJIC between small luteal cells during the fully differentiated (mid-luteal) and regressing (late luteal) stages of the estrous cycle. In contrast, at all stages of luteal development, activation of PKC decreases GJIC between small and between large and small luteal cells, whereas calcium ionophore decreases GJIC only between large and small luteal cells. Luteotropic and luteolytic hormones, and intracellular regulators, may be involved in regulation of cellular interactions within bovine CL which likely is an important mechanism for coordination of luteal function.
 ...
PMID:Gap junctional intercellular communication of bovine luteal cells from several stages of the estrous cycle: effects of prostaglandin F2 alpha, protein kinase C and calcium. 893 84


1 2 3 Next >>