Effects of prostaglandins E1, E2, and F2alpha on the growth of leukaemia cells in culture

1976 ◽  
Vol 20 (1) ◽  
pp. 199-206
Author(s):  
T.J. Yang ◽  
J.B. Dale ◽  
R. Machanoff
Keyword(s):  
Tritiated Thymidine ◽  
Inhibitory Effect ◽  
Soft Agar ◽  
Significant Inhibition ◽  
Leucine Incorporation ◽  
Inhibitory Effects ◽  
Uridine Incorporation ◽  
Cells In Culture ◽  
Mouse Leukaemia

Prostaglandins E1, E2, and F2alpha (PGE1, PGE2, and PGF2alpha) were shown to inhibit the growth of mouse leukaemia lymphoblasts L5178Y in culture. The effects of PGE1 and PGE2 were greater than that of PGF2alpha. PGE1 and PGE2, at the concentration of 100 mug per ml showed significant inhibitory effects on the rates of incorporation of tritiated thymidine, uridine and leucine. At concentrations of 50 and 25 mug per ml, there was significant inhibition of thymidine and uridine incorporation, but not of leucine, PGF2alpha showed significant inhibition of thymidine and uridine incorporation but not leucine incorporation, in all 3 concentrations studied (100, 50, and 25 mug/ml). The ability of the cells to form colonies in soft agar was significantly inhibited by PGE1 and PGE2 at concentrations as low as 1–8 mug/ml. For F2alpha, however, a concentration as high as 56mug/ml was required to show inhibitory effect, but at 1–8 mug/ml it was found to be stimulatory.

Effect of GnRH-associated peptide on prolactin secretion from human lactotrope adenoma cells in culture

1987 ◽  
Vol 116 (1) ◽  
pp. 81-84 ◽  
Author(s):  
Miyuki Ishibashi ◽  
Tohru Yamaji ◽  
Fumimaro Takaku ◽  
Akira Teramoto ◽  
Takanori Fukushima ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Inhibitory Effect ◽  
Prolactin Secretion ◽  
Significant Inhibition ◽  
The Other ◽  
Human Pituitary ◽  
Gh Secretion ◽  
Cells In Culture ◽  
Other Hand ◽  
Transsphenoidal Adenomectomy

Abstract. The effect of GnRH-associated peptide on PRL secretion by human pituitary lactotropes in culture was studied. Pituitary adenomas obtained at selective transsphenoidal adenomectomy from a patient with prolactinoma, and two patients with mixed GH- and PRL-secreting pituitary adenomas were cultured in monolayer. When cells were incubated with dopamine (10 nmol/l), a significant inhibition in PRL secretion was observed in all the experiments, which was blocked by co-incubation with haloperidol. In mixed GH- and PRL-secreting adenoma cells, dopamine likewise decreased GH secretion. Incubation of cells with synthetic GnRH-associated peptide at concentrations up to 100 nmol/l, on the other hand, failed to affect both PRL and GH secretion. These results suggest that synthetic GnRH-associated peptide has no inhibitory effect on PRL secretion in human pituitary lactotropes.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Inhibition of ADP-Induced Responses in Human Platelets by Agents Elevating the Cyclic AMP Level: Comparison of Aggregation and Shape Change

1984 ◽  
Vol 52 (03) ◽  
pp. 333-335 ◽  
Author(s):  
Vider M Steen ◽  
Holm Holmsen
Keyword(s):  
Inhibitory Action ◽  
Human Platelet ◽  
Platelet Rich Plasma ◽  
Shape Change ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Inhibitory Effects ◽  
Early Step ◽  
Stimulus Response ◽  
Sequential Relationship

SummaryThe inhibitory effect of cAMP-elevating agents on shape change and aggregation in human platelets was studied to improve the understanding of the sequential relationship between these two responses.Human platelet-rich plasma was preincubated for 2 min at 37° C with prostaglandin E1 or adenosine, agents known to elevate the intracellular level of cAMP. Their inhibitory effects on ADP-induced shape change and aggregation were determined both separately and simultaneously. The dose-inhibition patterns for shape change and aggregation were similar for both PGE1 and adenosine. There was no distinct difference between the inhibitory action of these two inhibitors.These observations suggest that elevation of the intracellular concentration of cAMP interferes with an early step in the stimulus-response coupling that is common for aggregation and shape change.

The Inhibitory Effect of Heparin and Related Glycosaminoglycans on Neutrophil Chemotaxis

1984 ◽  
Vol 52 (02) ◽  
pp. 134-137 ◽  
Author(s):  
Yaacov Matzner ◽  
Gerard Marx ◽  
Ruth Drexler ◽  
Amiram Eldor
Keyword(s):  
Specific Binding ◽  
Anticoagulant Activity ◽  
Neutrophil Migration ◽  
Inhibitory Effect ◽  
Chemotactic Factor ◽  
Human Neutrophils ◽  
Boyden Chamber ◽  
Neutrophil Chemotaxis ◽  
Inhibitory Effects ◽  
Chemotactic Factors

SummaryClinical observations have shown that heparin has antiinflammatory activities. The effect of heparin on neutrophil chemotaxis was evaluated in vitro in the Boyden Chamber. This method enabled differentiation between the direct effects of heparin on neutrophil migration and locomotion, and its effects on chemotactic factors. Heparin inhibited both the random migration and directed locomotion of human neutrophils toward zymosan-activated serum (ZAS) and F-met-leu-phe (FMLP). Inhibition was found to be dependent on the concentrations of the heparin and of the chemotactic factors. No specific binding of heparin to the neutrophils could be demonstrated, and heparin’s inhibitory effects were eliminated by simple washing of the cells. When added directly to the chamber containing chemotactic factor, heparin inhibited the chemotactic activity of ZAS but not that of FMLP, suggesting a direct inhibitory effect against C5a, the principal chemotactic factor in ZAS.Experiments performed with low-molecular-weight heparin, N-desulfated heparin, dextran sulfate, chondroitin sulfate and dextran indicated that the inhibitory effects of heparin on neutrophil chemotaxis are not related to its anticoagulant activity, but probably depend on the degree of sulfation of the heparin molecule.

A comparative study of the antibacterial activity of Quercus robur (Ethanolic extract) and Zinc oxide nanoparticles on Salmonella (In vitro)

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Hams H. H. Alfattli ◽  
Ghufran Zuhair Jiber ◽  
Ghaidaa Gatea Abbass
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Zinc Oxide Nanoparticles ◽  
Quercus Robur ◽  
Ethanolic Extract ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Oxide Nanoparticles ◽  
Inhibition Zones

This study which designed to evaluate the inhibitory effect of Ethanolic extract of (Quercusrobur) and Zinc oxide nanoparticles on the growth of one genus of enterobacteriacae (Salmonella). In vitro. For this purpose graduate concentrates for plant extract (50, 100, 200, 400 )mg/ml which prepared and compared with Zinc oxide nanoparticles of different concentration (2, 1, 0.5, 0.25) μg/ml,and examined. The result showed that the studied medicinal plant has antibacterial activity against this bacteria which used. The result showed that the plant has good activity in decrease the growth of this bacteria. The results of the study also showed that the nano-ZnO has very effective antibacterial action against the studied bacteria which was Salmonella,nanoparticles concentrations lead to increasing in the inhibition zones of tested bacterial growth. We also study the effect of three antibiotics Lomefloxacin (LOM), Ciprofloxacin (SIP) and Rifampin (RA) and the result showed,in a comparison within the tested bacteria,Salmonella had a significant inhibition increase in Lomefloxacin ; the ciprofloxacin showed effect on tested bacteria. However,Rifampin does not show any effect on tested bacteria.

Inhibition of Yeast Growth by Tryptamine and Recovery with Tryptophan

2020 ◽  
Vol 16 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Chandrika Kadkol ◽  
Ian Macreadie
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Competitive Inhibition ◽  
Yeast Species ◽  
Inhibitory Effect ◽  
The Body ◽  
Inhibitory Effects ◽  
Trna Synthetases ◽  
Fermentative Growth ◽  
Biogenic Monoamine

Background: Tryptamine, a biogenic monoamine that is present in trace levels in the mammalian central nervous system, has probable roles as a neurotransmitter and/or a neuromodulator and may be associated with various neuropsychiatric disorders. One of the ways tryptamine may affect the body is by the competitive inhibition of the attachment of tryptophan to tryptophanyl tRNA synthetases. Methods: This study has explored the effects of tryptamine on growth of six yeast species (Saccharomyces cerevisiae, Candida glabrata, C. krusei, C. dubliniensis, C. tropicalis and C. lusitaniae) in media with glucose or ethanol as the carbon source, as well as recovery of growth inhibition by the addition of tryptophan. Results: Tryptamine was found to have an inhibitory effect on respiratory growth of all yeast species when grown with ethanol as the carbon source. Tryptamine also inhibited fermentative growth of Saccharomyces cerevisiae, C. krusei and C. tropicalis with glucose as the carbon source. In most cases the inhibitory effects were reduced by added tryptophan. Conclusion: The results obtained in this study are consistent with tryptamine competing with tryptophan to bind mitochondrial and cytoplasmic tryptophanyl tRNA synthetases in yeast: effects on mitochondrial and cytoplasmic protein synthesis can be studied as a function of growth with glucose or ethanol as a carbon source. Of the yeast species tested, there is variation in the sensitivity to tryptamine and the rescue by tryptophan. The current study suggests appropriate yeast strains and approaches for further studies.

Molecular Mechanisms of the Inhibitory Effects of Bupivacaine, Levobupivacaine, and Ropivacaine on Sarcolemmal Adenosine Triphosphate–sensitive Potassium Channels in the Cardiovascular System

2004 ◽  
Vol 101 (2) ◽  
pp. 390-398 ◽  
Author(s):  
Takashi Kawano ◽  
Shuzo Oshita ◽  
Akira Takahashi ◽  
Yasuo Tsutsumi ◽  
Yoshinobu Tomiyama ◽  
...  
Keyword(s):  
Cardiovascular System ◽  
Adenosine Triphosphate ◽  
Local Anesthetics ◽  
Molecular Mechanisms ◽  
Transmembrane Domain ◽  
Katp Channels ◽  
Inhibitory Effect ◽  
Amino Acid Residues ◽  
Sulfonylurea Receptor ◽  
Inhibitory Effects

Background Sarcolemmal adenosine triphosphate-sensitive potassium (KATP) channels in the cardiovascular system may be involved in bupivacaine-induced cardiovascular toxicity. The authors investigated the effects of local anesthetics on the activity of reconstituted KATP channels encoded by inwardly rectifying potassium channel (Kir6.0) and sulfonylurea receptor (SUR) subunits. Methods The authors used an inside-out patch clamp configuration to investigate the effects of bupivacaine, levobupivacaine, and ropivacaine on the activity of reconstituted KATP channels expressed in COS-7 cells and containing wild-type, mutant, or chimeric SURs. Results Bupivacaine inhibited the activities of cardiac KATP channels (IC50 = 52 microm) stereoselectively (levobupivacaine, IC50 = 168 microm; ropivacaine, IC50 = 249 microm). Local anesthetics also inhibited the activities of channels formed by the truncated isoform of Kir6.2 (Kir6.2 delta C36) stereoselectively. Mutations in the cytosolic end of the second transmembrane domain of Kir6.2 markedly decreased both the local anesthetics' affinity and stereoselectivity. The local anesthetics blocked cardiac KATP channels with approximately eightfold higher potency than vascular KATP channels; the potency depended on the SUR subtype. The 42 amino acid residues at the C-terminal tail of SUR2A, but not SUR1 or SUR2B, enhanced the inhibitory effect of bupivacaine on the Kir6.0 subunit. Conclusions Inhibitory effects of local anesthetics on KATP channels in the cardiovascular system are (1) stereoselective: bupivacaine was more potent than levobupivacaine and ropivacaine; and (2) tissue specific: local anesthetics blocked cardiac KATP channels more potently than vascular KATP channels, via the intracellular pore mouth of the Kir6.0 subunit and the 42 amino acids at the C-terminal tail of the SUR2A subunit, respectively.

scholarly journals Identification of 3-chymotrypsin like protease (3CLPro) inhibitors as potential anti-SARS-CoV-2 agents

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Vicky Mody ◽  
Joanna Ho ◽  
Savannah Wills ◽  
Ahmed Mawri ◽  
Latasha Lawson ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Dynamics Simulation ◽  
Simulation Studies ◽  
Inhibitory Effects ◽  
Major Threat ◽  
Main Protease ◽  
Approved Drugs ◽  
Fda Approved Drugs ◽  
Computational Molecular Modeling

AbstractEmerging outbreak of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is a major threat to public health. The morbidity is increasing due to lack of SARS-CoV-2 specific drugs. Herein, we have identified potential drugs that target the 3-chymotrypsin like protease (3CLpro), the main protease that is pivotal for the replication of SARS-CoV-2. Computational molecular modeling was used to screen 3987 FDA approved drugs, and 47 drugs were selected to study their inhibitory effects on SARS-CoV-2 specific 3CLpro enzyme in vitro. Our results indicate that boceprevir, ombitasvir, paritaprevir, tipranavir, ivermectin, and micafungin exhibited inhibitory effect towards 3CLpro enzymatic activity. The 100 ns molecular dynamics simulation studies showed that ivermectin may require homodimeric form of 3CLpro enzyme for its inhibitory activity. In summary, these molecules could be useful to develop highly specific therapeutically viable drugs to inhibit the SARS-CoV-2 replication either alone or in combination with drugs specific for other SARS-CoV-2 viral targets.

scholarly journals Study on the Inhibitory Activity of a Synthetic Defensin Derived from Barley Endosperm against Common Food Spoilage Yeast

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 165
Author(s):  
Laila N. Shwaiki ◽  
Aylin W. Sahin ◽  
Elke K. Arendt
Keyword(s):  
Apple Juice ◽  
Digestive Enzyme ◽  
Inhibitory Effect ◽  
Food Preservation ◽  
Food Spoilage ◽  
Inhibitory Effects ◽  
Barley Endosperm ◽  
Spoilage Yeast ◽  
Spoilage Yeasts ◽  
Spoilage Microorganisms

In the food industry, food spoilage is a real issue that can lead to a significant amount of waste. Although current preservation techniques are being applied to reduce the occurrence of spoilage microorganisms, the problem persists. Food spoilage yeast are part of this dilemma, with common spoilers such as Zygosaccharomyces, Kluyveromyces, Debaryomyces and Saccharomyces frequently encountered. Antimicrobial peptides derived from plants have risen in popularity due to their ability to reduce spoilage. This study examines the potential application of a synthetic defensin peptide derived from barley endosperm. Its inhibitory effect against common spoilage yeasts, its mechanisms of action (membrane permeabilisation and overproduction of reactive oxygen species), and its stability in different conditions were characterised. The safety of the peptide was evaluated through a haemolysis and cytotoxicity assay, and no adverse effects were found. Both assays were performed to understand the effect of the peptide if it were to be consumed. Its ability to be degraded by a digestive enzyme was also examined for its safety. Finally, the peptide was successfully applied to different beverages and maintained the same inhibitory effects in apple juice as was observed in the antiyeast assays, providing further support for its application in food preservation.

scholarly journals Amphetamine-Decreased Progesterone and Estradiol Release in Rat Granulosa Cells: The Regulatory Role of cAMP- and Ca2+-Mediated Signaling Pathways

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 493
Author(s):  
 Chung-Yu Chen ◽  
Chien-Rung Chen ◽  
Chiao-Nan Chen ◽  
Paulus S. Wang ◽  
Toby Mündel ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Prostaglandin F2α ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Steroidogenic Enzyme ◽  
Estradiol Secretion ◽  
Basal Release ◽  
Ca2 Channels

The purpose of this study is to evaluate the amphetamine effects on progesterone and estradiol production in rat granulosa cells and the underlying cellular regulatory mechanisms. Freshly dispersed rat granulosa cells were cultured with various test drugs in the presence of amphetamine, and the estradiol/progesterone production and the cytosolic cAMP level were measured. Additionally, the cytosolic-free Ca2+ concentrations ([Ca2+]i) were measured to examine the role of Ca2+ influx in the presence of amphetamine. Amphetamine in vitro inhibited both basal and porcine follicle-stimulating hormone-stimulated estradiol/progesterone release, and amphetamine significantly decreased steroidogenic enzyme activities. Adding 8-Bromo-cAMP did not recover the inhibitory effects of amphetamine on progesterone and estradiol release. H89 significantly decreased progesterone and estradiol basal release but failed to enhance a further amphetamine inhibitory effect. Amphetamine was capable of further suppressing the release of estradiol release under the presence of nifedipine. Pretreatment with the amphetamine for 2 h decreased the basal [Ca2+]i and prostaglandin F2α-stimulated increase of [Ca2+]i. Amphetamine inhibits progesterone and estradiol secretion in rat granulosa cells through a mechanism involving decreased PKA-downstream steroidogenic enzyme activity and L-type Ca2+ channels. Our current findings show that it is necessary to study the possibility of amphetamine perturbing reproduction in females.

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