Effects of colchicine and vinblastine on in vitro gastric secretion.

1979 ◽  
Vol 236 (5) ◽  
pp. E550
Author(s):  
D K Kasbekar ◽  
G S Gordon
Keyword(s):  
Gastric Secretion ◽  
Cytochalasin B ◽  
Pepsinogen Secretion ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Kinetics Of ◽  
Dose Dependent ◽  
Kinetics Of Inhibition ◽  
Stimulation Of

The effects of colchicine and vinblastine on in vitro bullfrog gastric mucosal preparations were studied with respect to H+ and pepsinogen secretion. In the concentration range of 1--50 mM, an initial but transient colchicine-mediated stimulation of H+ secretion is followed by a dose-dependent inhibition. The transient stimulation of H+ secretion can be confirmed in resting preparations in the absence of added secretagogues. In the same concentration range, colchicine inhibits pepsinogen secretion to a greater degree than H+ secretion. Vinblastine (10(-5)--5 X 10(-4) M) was more effective than colchicine in inhibiting both H+ and pepsinogen secretion. The kinetics of inhibition of secretion by both colchicine and vinblastine were slow. Cytochalasin B had no effect on either secretion.

RNA synthesis in the Leydig cells of the mature rat: effect of oestradiol-17β

1988 ◽  
Vol 116 (3) ◽  
pp. 387-392 ◽  
Author(s):  
A. M. Ronco ◽  
A. M. Pino ◽  
L. E. Valladares
Keyword(s):  
Leydig Cells ◽  
Rna Synthesis ◽  
Human Chorionic Gonadotrophin ◽  
Testicular Cells ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
High Concentrations ◽  
Kinetics Of ◽  
Dose Dependent

ABSTRACT In view of the evidence that there may be an effect of high concentrations of oestradiol on testicular steroidogenic function, we have investigated the effect of this steroid on [3H]uridine incorporation into RNA by testicular cells. Our results have shown that oestradiol in vitro induced a marked dose-dependent inhibition of RNA synthesis by purified Leydig cells. The concentrations of oestradiol tested varied from 2 to 40 μmol/l; these concentrations also impaired net testosterone synthesis in vitro after human chorionic gonadotrophin (hCG) stimulation. Under the effect of oestradiol, the kinetics of [3H]nucleoside incorporation into RNA were impaired early and the inhibition of RNA synthesis was specific for oestrogenic compounds. It was concluded that, in Leydig cells, oestradiol, in addition to its known inhibitory action on the response of testosterone to hCG, triggers a more extensive response that also includes RNA synthesis in vitro. J. Endocr. (1988) 116, 387–392

Differences between antigenic determinants of pig and cat zona pellucida proteins

Reproduction ◽  
2000 ◽  
pp. 15-23 ◽  
Author(s):  
K Jewgenow ◽  
M Rohleder ◽  
I Wegner
Keyword(s):  
In Vitro Fertilization ◽  
Zona Pellucida ◽  
Antigenic Determinants ◽  
Vitro Fertilization ◽  
Contraceptive Vaccine ◽  
Sperm Binding ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Despite many efforts, the control of reproduction in feral cat populations is still a problem in urban regions around the world. Immunocontraception is a promising approach; thus the present study examined the suitability of the widely used pig zona pellucida proteins (pZP) for contraception in feral domestic cats. Purified zona pellucida proteins obtained from pig and cat ovaries were used to produce highly specific antisera in rabbits. Antibodies against pZP raised in rabbits or lions were not effective inhibitors of either in vitro sperm binding (cat spermatozoa to cat oocytes) or in vitro fertilization in cats, whereas antibodies against feline zona pellucida proteins (fZP) raised in rabbits showed a dose-dependent inhibition of in vitro fertilization. Immunoelectrophoresis, ELISA and immunohistology of ovaries confirmed these results, showing crossreactivity of anti-fZP sera to fZP and to a lesser extent to pZP, but no interaction of anti-pZP sera with fZP. It is concluded that cat and pig zonae pellucidae express a very small number of shared antigenic determinants, making the use of pZP vaccine in cats questionable. A contraceptive vaccine based on feline zona pellucida determinants will be a better choice for the control of reproduction in feral cats if immunogenity can be achieved.

scholarly journals In VitroActivities of Hexaazatrinaphthylenes against Leishmania spp.

2015 ◽  
Vol 59 (5) ◽  
pp. 2867-2874 ◽  
Author(s):  
Atteneri López-Arencibia ◽  
Daniel García-Velázquez ◽  
Carmen M. Martín-Navarro ◽  
Ines Sifaoui ◽  
María Reyes-Batlle ◽  
...  
Keyword(s):  
Therapeutic Agents ◽  
Content Type ◽  
Inhibition Effect ◽  
Intracellular Amastigotes ◽  
Dependent Inhibition ◽  
Leishmania Spp ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Potential Use

ABSTRACTThein vitroactivity of a novel group of compounds, hexaazatrinaphthylene derivatives, against two species ofLeishmaniais described in this study. These compounds showed a significant dose-dependent inhibition effect on the proliferation of the parasites, with 50% inhibitory concentrations (IC50s) ranging from 1.23 to 25.05 μM against the promastigote stage and 0.5 to 0.7 μM against intracellular amastigotes. Also, a cytotoxicity assay was carried out to in order to evaluate the possible toxic effects of these compounds. Moreover, different assays were performed to determine the type of cell death induced after incubation with these compounds. The obtained results highlight the potential use of hexaazatrinaphthylene derivatives againstLeishmaniaspecies, and further studies should be undertaken to establish them as novel leishmanicidal therapeutic agents.

scholarly journals In vitro interactions of PGE and cAMP with murine and human erythroid precursors

Blood ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 74-79 ◽  
Author(s):  
GB Rossi ◽  
AR Migliaccio ◽  
G Migliaccio ◽  
F Lettieri ◽  
M Di Rosa ◽  
...  
Keyword(s):  
Inhibitory Action ◽  
Colony Growth ◽  
Inhibitory Influence ◽  
Adherent Cells ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Stimulating Factor ◽  
In Vitro Interactions

Abstract Addition of prostaglandins of the E series (PGE1, PGE2) in methylcellulose cultures of murine marrow results in a dose-dependent inhibition of the cloning efficiency of both BFU-E and CFU-C. However, CFU-E growth is unaffected. The inhibitory action of PGE is progressively overcome by increasing amounts of colony-stimulating factor (CSF), and with some limitations, also of erythropoietin (Ep). Addition of PGF2 alpha' associated or not with indomethacin, does not exert any significant effect on these hemopoietic precursors. In an attempt to unvail the mechanism(s) underlying these phenomena, dibutyryl-cyclic AMP (db-cAMP), theophylline (an inhibitor of phosphodiesterase), or theophylline + PGE were plated at various concentrations. Both db-cAMP and theophylline induce an inhibitory influence on both BFU-E and CFU-C growth, which mimicks that by PGEs; additionally, theophylline potentiates the inhibitory action of PGE1. In all these studies, the CFU-E number was not significantly modified. PGE action on BFU-E proliferation is clearly species-dependent, since PGE1 addition to human marrow methylcellulose cultures induces a significant enhancement of the number of both BFU-E and CFU-E derived colonies. This action was abolished upon removal of adherent cells, thus suggesting that PGE1 evokes a release of factor(s) enhancing human erythroid colony growth by adherent cells.

scholarly journals Proteoglycan and glycosaminoglycan synthesis in embryonic mouse salivary glands: effects of beta-D-xyloside, an inhibitor of branching morphogenesis.

1983 ◽  
Vol 96 (5) ◽  
pp. 1443-1450 ◽  
Author(s):  
H A Thompson ◽  
B S Spooner
Keyword(s):  
Salivary Glands ◽  
Dermatan Sulfate ◽  
Branching Morphogenesis ◽  
Proteoglycan Synthesis ◽  
Embryonic Mouse ◽  
Glycosaminoglycan Synthesis ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Stimulation Of

The proteoglycans and glycosaminoglycans synthesized by embryonic mouse salivary glands during normal morphogenesis and in the presence of beta-xyloside, an inhibitor of branching morphogenesis, have been partially characterized. Control and rho-nitrophenyl-beta-D-xyloside-treated salivary rudiments synthesize proteoglycans that are qualitatively similar, based on mobility on Sepharose CL-4B under dissociative conditions and glycosaminoglycan composition. However, beta-xyloside inhibits total proteoglycan-associated glycosaminoglycan synthesis by 50%, and also stimulates synthesis of large amounts of free chondroitin (dermatan) sulfate. This free glycosaminoglycan accounts for the threefold stimulation of total glycosaminoglycan synthesis in beta-xyloside-treated cultures. Several observations suggest that the disruption of proteoglycan synthesis rather than the presence of large amounts of free glycosaminoglycan is responsible for the inhibition of branching morphogenesis. (a) We have been unable to inhibit branching activity by adding large amounts of chondroitin (dermatan) sulfate, extracted from beta-xyloside-treated cultures, to the medium of salivary rudiments undergoing morphogenesis. (b) In the range of 0.1-0.4 mM beta-xyloside, the dose-dependent inhibition of branching morphogenesis is directly correlated with the inhibition of proteoglycan synthesis. The stimulation of free glycosaminoglycan synthesis is independent of dose in this range, since stimulation is maximal even at the lowest concentration used, 0.1 mM. The data strongly suggest that the inhibition of branching morphogenesis is caused by the disruption of proteoglycan synthesis in beta-xyloside-treated salivary glands.

scholarly journals On the Molecular Pharmacology of Resveratrol on Oxidative Burst Inhibition in Professional Phagocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Radomír Nosáľ ◽  
Katarína Drábiková ◽  
Viera Jančinová ◽  
Tomáš Perečko ◽  
Gabriela Ambrožová ◽  
...  
Keyword(s):  
Oxidative Burst ◽  
Antioxidant Activities ◽  
Raw 264.7 Cells ◽  
Human Neutrophils ◽  
Nitrite Production ◽  
Inos Protein Expression ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Resveratrol—3,5,4′-trihydroxystilbene—possesses antioxidant activitiesin vitro. It dose-dependently inhibited the generation of peroxyl, hydroxyl, peroxides, and lipid peroxidation products in cell free systems. Oxidative burst of whole human blood stimulated with PMA, fMLP, OpZ, and A23187 was inhibited in a concentration-dependent way, indicating suppression of both receptor and nonreceptor activated chemiluminescence by resveratrol. Results from isolated human neutrophils revealed that resveratrol was active extracellularly as well as intracellularly in inhibiting the generation of reactive oxygen species. Liberation of ATP and analysis of apoptosis showed that in the concentration of 100 μM, resveratrol did not change the viability and integrity of isolated neutrophils. Western blot analysis documented that resveratrol in concentrations of 10 and 100 μM significantly decreased PMA-induced phosphorylation of PKCα/βII. Dose-dependent inhibition of nitrite production and iNOS protein expression in RAW 264.7 cells indicated possible interference of resveratrol with reactive nitrogen radical generation in professional phagocytes. The results suggest that resveratrol represents an effective naturally occurring substance with potent pharmacological effect on oxidative burst of human neutrophils and nitric oxide production by macrophages. It should be further investigated for its pharmacological activity against oxidative stress in ischaemia reperfusion, inflammation, and other pathological conditions, particularly neoplasia.

scholarly journals Influence of Human Sera on the In Vitro Activity of the Echinocandin Caspofungin (MK-0991) against Aspergillus fumigatus

2000 ◽  
Vol 44 (12) ◽  
pp. 3302-3305 ◽  
Author(s):  
Tom Chiller ◽  
Kouros Farrokhshad ◽  
Elmer Brummer ◽  
David A. Stevens
Keyword(s):  
Aspergillus Fumigatus ◽  
Human Serum ◽  
Hyphal Growth ◽  
Significant Inhibition ◽  
Dependent Inhibition ◽  
Human Sera ◽  
Dose Dependent Inhibition ◽  
Synthase Inhibitor ◽  
Dose Dependent

ABSTRACT There have been several reports that the activity of echinocandin antifungal agents is not affected or decreased in the presence of human sera. It is known that these drugs are bound >80% in animal and human sera. The activity of the echinocandin caspofungin (MK-0991), a 1,3-β-d-glucan synthase inhibitor, againstAspergillus fumigatus with and without human sera was studied. Conidia of A. fumigatus in microtest plate wells formed germlings after overnight culture in RPMI 1640. Caspofungin was then added with or without serum, and the germlings were incubated at 37°C for 24 h. Human serum (5%) in RPMI 1640 alone did not significantly inhibit the growth of A. fumigatus in vitro. Caspofungin in RPMI 1640 exhibited dose-dependent inhibition, with concentrations of 0.1 and 0.05 μg/ml inhibiting 24.9% +/− 10.4% and 11.7% +/− 3.6%, respectively (n = 10;P < 0.01). The addition of 5% human serum to caspofungin at 0.1 or 0.05 μg/ml increased the inhibition to 78.6% +/− 5.8% or 58.3% +/− 19.2%, respectively (n = 10; P < 0.01 versus controls and versus the drug without serum). Lower concentrations of serum also potentiated drug activity. The effect of human sera was further seen when using caspofungin that had lost activity (e.g., by storage) against A. fumigatus at 0.1 μg/ml. Inactive caspofungin alone demonstrated no significant inhibition of hyphal growth, whereas the addition of 5% human serum to the inactive drug showed 83% +/− 16.5% inhibition (n = 5; P < 0.01). The restoration of activity of caspofungin was seen at concentrations as low as 0.05% human serum. In contrast to prior reports, this study suggests that human serum acts synergistically with caspofungin to enhance its inhibitory activity in vitro against A. fumigatus.

scholarly journals In vitro interactions of PGE and cAMP with murine and human erythroid precursors

Blood ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 74-79 ◽  
Author(s):  
GB Rossi ◽  
AR Migliaccio ◽  
G Migliaccio ◽  
F Lettieri ◽  
M Di Rosa ◽  
...  
Keyword(s):  
Inhibitory Action ◽  
Colony Growth ◽  
Inhibitory Influence ◽  
Adherent Cells ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Stimulating Factor ◽  
In Vitro Interactions

Addition of prostaglandins of the E series (PGE1, PGE2) in methylcellulose cultures of murine marrow results in a dose-dependent inhibition of the cloning efficiency of both BFU-E and CFU-C. However, CFU-E growth is unaffected. The inhibitory action of PGE is progressively overcome by increasing amounts of colony-stimulating factor (CSF), and with some limitations, also of erythropoietin (Ep). Addition of PGF2 alpha' associated or not with indomethacin, does not exert any significant effect on these hemopoietic precursors. In an attempt to unvail the mechanism(s) underlying these phenomena, dibutyryl-cyclic AMP (db-cAMP), theophylline (an inhibitor of phosphodiesterase), or theophylline + PGE were plated at various concentrations. Both db-cAMP and theophylline induce an inhibitory influence on both BFU-E and CFU-C growth, which mimicks that by PGEs; additionally, theophylline potentiates the inhibitory action of PGE1. In all these studies, the CFU-E number was not significantly modified. PGE action on BFU-E proliferation is clearly species-dependent, since PGE1 addition to human marrow methylcellulose cultures induces a significant enhancement of the number of both BFU-E and CFU-E derived colonies. This action was abolished upon removal of adherent cells, thus suggesting that PGE1 evokes a release of factor(s) enhancing human erythroid colony growth by adherent cells.

Effect of PGE2 and alpha-adrenergic agonists on AVP-dependent cAMP levels in rabbit and rat CCT

1988 ◽  
Vol 255 (1) ◽  
pp. F43-F48 ◽  
Author(s):  
D. Chabardes ◽  
C. Brick-Ghannam ◽  
M. Montegut ◽  
S. Siaume-Perez
Keyword(s):  
Adrenergic Agonists ◽  
Camp Production ◽  
Synthesis Inhibitor ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Prostaglandin Synthesis Inhibitor ◽  
Collecting Tubules ◽  
Camp Levels ◽  
Dose Dependent

The effect of prostaglandins and alpha-adrenergic agonists on arginine vasopressin-induced adenosine 3',5'-cyclic monophosphate (cAMP) production was investigated in microdissected rat and rabbit cortical collecting tubules (CCT) incubated in vitro. In rabbit CCT, addition to all media of a prostaglandin synthesis inhibitor increased this production; exogenous prostaglandin E2 (PGE2) induced a reproducible dose-dependent inhibition of cAMP accumulation. Maximal inhibition (mean: 57.5%) was observed with 0.3 microM PGE2, and threshold inhibition was observed with concentrations ranging from 3 to 10 nM PGE2. Inhibition of cAMP levels in rabbit CCT was also obtained with 0.3 microM PGF2 alpha (mean inhibition: 44.3%) but not with alpha-adrenergic agonists studied under the same conditions. The opposite was observed in rat CCT studied in parallel: the alpha-agonists inhibited cAMP production by up to 80%, but PGE2 had no effect.

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