Bismuth-inhibitory effects on bacteria and stimulation of fungal growth in vitro

1. Pretreatment of female rats with (−)-emetine or (±)-2,3-dehydroemetine (at 18μmol/kg body wt. for 24h) prolongs the hexobarbital-induced sleeping-time of the treated animals. 2. This effect is not observed on pretreating animals with other compounds closely related to (−)-emetine, such as (−)-isoemetine or (+)-O-methylpsychotrine. 3. Liver microsomal drug-metabolizing enzyme activity in vitro as measured by N-demethylation of aminopyrine and azo-reduction of Neoprontosil is inhibited in rats pretreated with (−)-emetine or with (±)-2,3-dehydroemetine. 4. These inhibitory effects on drug metabolism in vitro are not observed in corresponding experiments involving pretreatment of rats with (−)-isoemetine or (+)-O-methylpsychotrine. 5. Co-administration of emetine or 2,3-dehydroemetine and sodium phenobarbital or 1,1-dichloro-2-o-chlorophenyl-2-p-chlorophenylethane to rats abolishes or greatly diminishes the stimulation of drug-metabolizing enzyme activity in vitro usually obtained by the administration of phenobarbital or 1,1-dichloro-2-o-chlorophenyl-2-p-chlorophenylethane alone. 6. Further, in rats pretreated with sodium phenobarbital and subsequently injected with emetine or 2,3-dehydroemetine the pre-stimulated drug-metabolizing enzyme activity in vitro is diminished. 7. The inhibitory effects on drug-metabolizing enzyme activity after pretreatment with (−)-emetine or (±)-2,3-dehydroemetine do not appear to be related to NADPH generation.

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Excitatory and inhibitory effects of gastrin peptides on gastric motility in sheep

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1989.257.2.r388 ◽

1989 ◽

Vol 257 (2) ◽

pp. R388-R395 ◽

Cited By ~ 1

Author(s):

L. M. McLeay ◽

M. H. Wong

Keyword(s):

The Body ◽

Inhibitory Effects ◽

Cholinergic Neurones ◽

Conscious Sheep ◽

Nerve Muscle ◽

Human Gastrin ◽

Mixed Nerve ◽

Stimulation Of

In conscious sheep, tetragastrin, pentagastrin, and synthetic human gastrin I, injected either subcutaneously or intravenously in doses of 156-5,200 pmol/kg body wt, inhibited the vagally dependent cyclical motility of the reticulum and rumen, whereas in vitro pentagastrin (10(-12) to 10(-6) M) had no demonstrable inhibitory or excitatory effects on intrinsically active or quiescent muscle of the reticulum, rumen, and omasal leaves. In vitro pentagastrin (10(-18) to 10(-4) M) stimulated quiescent and intrinsically active longitudinal and circular muscles of the body of the omasum and the body and antrum of the abomasum and potentiated contractile responses of antral muscle to electrical stimulation of intramural cholinergic nerves. Responses in the presence of hexamethonium, atropine, and tetrodotoxin indicated that the excitatory effects on mixed nerve-muscle preparations of omasal and abomasal tissue were mediated both through stimulation of cholinergic neurones and by direct actions on the muscle. In vitro the ovine stomach shows marked regional differences in both its response and sensitivity to gastrin peptides, and their inhibitory effects on reticuloruminal motility in vivo appear to be other than direct.

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Prebiotic effects of inulin and oligofructose

British Journal Of Nutrition ◽

10.1079/bjn/2002537 ◽

2002 ◽

Vol 87 (S2) ◽

pp. S193-S197 ◽

Cited By ~ 179

Author(s):

S. Kolida ◽

K. Tuohy ◽

G. R. Gibson

Keyword(s):

Food Product ◽

Inhibitory Effects ◽

Food Ingredients ◽

Acute Infections ◽

Health Promoting ◽

Human Large Intestine ◽

Gut Pathogens ◽

Stimulation Of

Prebiotics are non-digestible food ingredients that target certain components within the microbiota of the human large intestine. Efficient prebiotics need to have a specific fermentation therein and thereby have the ability to alter the faecal microflora composition towards a more ‘beneficial’ community structure. This should occur by the stimulation of benign or potentially health promoting genera but not the harmful groups. Because of their positive attributes bifidobacteria and lactobacilli are the most frequent target organisms. Both inulin and oligofructose have been demonstrated to be effective prebiotics. This has been shown through both in vitro and in vivo assessments in different laboratories. Because of their recognised prebiotic properties, principally the selective stimulation of colonic bifidobacteria, both inulin and oligofructose are increasingly used in new food product developments. Examples include drinks, yoghurts, biscuits and table spreads. Because of the recognised inhibitory effects that bifidobacteria can exert against gut pathogens, one of the most important aspects of prebiotic ingestion is fortification of the gut flora to resist acute infections.

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Inhibitory effects of progestogens on the estrogen stimulation of melanocytes in vitro

Contraception ◽

10.1016/j.contraception.2009.03.005 ◽

2009 ◽

Vol 80 (3) ◽

pp. 292-298 ◽

Cited By ~ 21

Author(s):

Christine Wiedemann ◽

Ursula Nägele ◽

Georg Schramm ◽

Carola Berking

Keyword(s):

Inhibitory Effects ◽

Estrogen Stimulation ◽

Stimulation Of

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Failure of 16,16-dimethyl PGE2 to prevent inhibitory effect of ethanol on sodium transport in canine gastric mucosa

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1985.248.3.g299 ◽

1985 ◽

Vol 248 (3) ◽

pp. G299-G306

Author(s):

T. A. Miller ◽

J. M. Henagan ◽

Y. J. Kuo ◽

L. L. Shanbour

Keyword(s):

Gastric Mucosa ◽

Sodium Transport ◽

Short Circuit ◽

Short Circuit Current ◽

Inhibitory Effect ◽

Gastric Epithelium ◽

Bathing Solution ◽

Inhibitory Effects ◽

Stimulation Of

By use of an in vitro canine gastric mucosal preparation, we evaluated the effects of ethanol (2, 4, 6, and 8%, vol/vol) and indomethacin (2.2 X 10(-4)M), with and without 16,16-dimethyl PGE2 pretreatment, on net sodium transport (JNanet) (mucosal to serosal) across gastric epithelium. Although administration of 2 or 4% ethanol to the mucosal bathing solution had no appreciable inhibitory effects on sodium transport, 6 and 8% ethanol and indomethacin significantly inhibited JNanet when compared with untreated control mucosa. This effect was accompanied by inhibition of transmucosal potential difference (PD) and short-circuit current (Isc). In other mucosae exposed to dimethyl PGE2 (8 X 10(-6) M) in the serosal bathing solution, significant increases in JNanet, PD, and Isc were noted when compared with control mucosa. Addition of 6 or 8% ethanol to the mucosal solution of dimethyl PGE2-pretreated tissue resulted in significant decreases in PD, Isc, and JNanet below control values that were not significantly different from mucosa exposed to 6 and 8% ethanol without PG pretreatment. When indomethacin was added to the mucosal solution following dimethyl PGE2 pretreatment, only slight decreases in PD and Isc below control levels were observed, and the inhibitory effects on JNanet induced by indomethacin without such treatment were abolished. These findings suggest that stimulation of JNanet by prostaglandin may play a role in its ability to prevent indomethacin damage to gastric epithelium but does not appear to be of importance in mediating protection against ethanol damage.

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Subthalamic Stimulation-Induced Synaptic Responses in Substantia Nigra Pars Compacta Dopaminergic Neurons In Vitro

Journal of Neurophysiology ◽

10.1152/jn.1999.82.2.925 ◽

1999 ◽

Vol 82 (2) ◽

pp. 925-933 ◽

Cited By ~ 74

Author(s):

Yuji Iribe ◽

Kevin Moore ◽

Kevin C. H. Pang ◽

James M. Tepper

Keyword(s):

Substantia Nigra ◽

Glutamate Receptor ◽

Dopaminergic Neurons ◽

Reversal Potential ◽

Substantia Nigra Pars Compacta ◽

Inhibitory Effects ◽

Synaptic Potentials ◽

Stimulation Of ◽

Synaptic Responses

The subthalamic nucleus (STN) is one of the principal sources of excitatory glutamatergic input to dopaminergic neurons of the substantia nigra, yet stimulation of the STN produces both excitatory and inhibitory effects on nigral dopaminergic neurons recorded extracellularly in vivo. The present experiments were designed to determine the sources of the excitatory and inhibitory effects. Synaptic potentials were recorded intracellularly from substantia nigra pars compacta dopaminergic neurons in parasagittal slices in response to stimulation of the STN. Synaptic potentials were analyzed for onset latency, amplitude, duration, and reversal potential in the presence and absence of GABA and glutamate receptor antagonists. STN-evoked depolarizing synaptic responses in dopaminergic neurons reversed at approximately −31 mV, intermediate between the expected reversal potential for an excitatory and an inhibitory postsynaptic potential (EPSP and IPSP). Blockade of GABAA receptors with bicuculline caused a positive shift in the reversal potential to near 0 mV, suggesting that STN stimulation evoked a near simultaneous EPSP and IPSP. Both synaptic responses were blocked by application of the glutamate receptor antagonist, 6-cyano-7-nitroquinoxalene-2,3-dione. The confounding influence of inhibitory fibers of passage from globus pallidus and/or striatum by STN stimulation was eliminated by unilaterally transecting striatonigral and pallidonigral fibers 3 days before recording. The reversal potential of STN-evoked synaptic responses in dopaminergic neurons in slices from transected animals was approximately −30 mV. Bath application of bicuculline shifted the reversal potential to ∼5 mV as it did in intact animals, suggesting that the source of the IPSP was within substantia nigra. These data indicate that electrical stimulation of the STN elicits a mixed EPSP-IPSP in nigral dopaminergic neurons due to the coactivation of an excitatory monosynaptic and an inhibitory polysynaptic connection between the STN and the dopaminergic neurons of substantia nigra pars compacta. The EPSP arises from a direct monosynaptic excitatory glutamatergic input from the STN. The IPSP arises polysynaptically, most likely through STN-evoked excitation of GABAergic neurons in substantia nigra pars reticulata, which produces feed-forward GABAA-mediated inhibition of dopaminergic neurons through inhibitory intranigral axon collaterals.

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Inhibitory Effects of Stilbenes on the Growth of Three Soybean Pathogens in Culture

Phytopathology ◽

10.1094/phyto-10-13-0287-r ◽

2014 ◽

Vol 104 (8) ◽

pp. 843-850 ◽

Cited By ~ 7

Author(s):

Anatoliy V. Lygin ◽

Curtis B. Hill ◽

Michelle Pawlowski ◽

Olga V. Zernova ◽

Jack M. Widholm ◽

...

Keyword(s):

Fungal Pathogens ◽

Area Under The Curve ◽

Fungal Growth ◽

Macrophomina Phaseolina ◽

Oxidation Products ◽

Initial Growth ◽

Inhibitory Effects ◽

Potato Dextrose Broth ◽

The Difference

The effects of resveratrol and pterostilbene on in vitro growth of three soybean pathogens were tested to determine whether these stilbenic compounds could potentially be targets to increase innate resistance in transgenic soybean plants. Growth of Macrophomina phaseolina, Rhizoctonia solani, and Sclerotinia sclerotiorum was measured on solid and in liquid media amended with resveratrol and pterostilbene (concentration in the media of resveratrol at 100 μg/ml and pterostilbene at 25 μg/ml). All three fungi were very sensitive to pterostilbene in potato dextrose agar (PDA), which reduced colony area of each of the three pathogens to less than half of the control 3 days after incubation. The three fungal pathogens were less sensitive to resveratrol compared with pterostilbene; however, area under the curve (AUC) calculated from colony areas measured over 3 days was significantly (P < 0.05) less than the control for S. sclerotiorum and R. solani on PDA with resveratrol or pterostilbene. AUC for M. phaseolina on PDA with pterostilbene was significantly (P < 0.05) lower than the control whereas, on PDA with resveratrol, AUC for M. phaseolina was lower than the control but the difference was nonsignificant (P > 0.05). AUC for all three fungi was significantly lower (P < 0.05) on PDA with pterostilbene than with resveratrol. In potato dextrose broth (PDB) shake cultures, AUC for all three fungi was significantly (P < 0.01) lower in pterostilbene than in the control. AUC for R. solani and S. sclerotiorum was significantly lower (P < 0.01) in resveratrol than the control, whereas AUC for M. phaseolina in resveratrol was lower, but not significantly (P > 0.05) different from the control. AUC in pterostilbene was highly significantly (P < 0.01) lower than in resveratrol for M. phaseolina and significantly (P < 0.05) lower for R. solani but the difference for S. sclerotiorum was nonsignificant (P > 0.05). There was a trend for lower mass accumulation of all three fungi in either pterostilbene or resveratrol compared with the control during the course of the experiment; however, S. sclerotiorum appeared to recover from the effects of pterostilbene between days 2 and 4. Results of biochemical analyses of the PDB over time indicated that the three fungi degraded resveratrol, with nearly 75% reduction in concentration in M. phaseolina, 80% in S. sclerotiorum, and 60% in R. solani PDB cultures by day 4 of fungal growth. M. phaseolina and S. sclerotiorum were able to resume growth after early inhibition by resveratrol after its concentration was reduced in the cultures through degradation, whereas R. solani was less efficient in resveratrol degradation and was not able to overcome its inhibitory effects on growth. The capacity to degrade pterostilbene was lowest in M. phaseolina compared with S. sclerotiorum and R. solani and the recovery of M. phaseolina cultures after initial growth inhibition by pterostilbene was minimal. The potential products of resveratrol and pterostilbene degradation by fungi were identified to be dimers and various oxidation products.

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Effects of insulin-like growth factor-II on growth hormone release from human somatotrophinoma cells in vitro

Journal of Endocrinology ◽

10.1677/joe.0.1290447 ◽

1991 ◽

Vol 129 (3) ◽

pp. 447-451 ◽

Cited By ~ 2

Author(s):

P. E. Harris ◽

M. Daniels ◽

R. A. James ◽

S. J. Turner ◽

J. Dewar ◽

...

Keyword(s):

Growth Factor ◽

Hormone Release ◽

Insulin Like Growth Factor ◽

Inhibitory Effects ◽

Variable Effect ◽

Gh Secretion ◽

Factor Ii ◽

Igf I ◽

Stimulation Of

ABSTRACT Insulin-like growth factor-I (IGF-I) and IGF-II receptors have previously been demonstrated on membranes prepared from human somatotrophinomas. IGF-I has been shown to have a variable effect on GH secretion by these tumours in vitro. The effects of purified IGF-II on GH secretion have not been described. We have studied the direct actions of human recombinant IGF-II on GH release from eight somatotrophinomas cultured in vitro. Somatotrophinoma cells were cultured as monolayers at a density of 105 cells/0·5 ml. Treatment with IGF-II for 4 and 24 h resulted in discrete inhibitory effects on GH release from two tumours (tumour 5:4 h, IGF-II 0·5 nmol/l; tumour 2; 24 h, IGF-II 1 nmol/l). Treatment with IGF-II for 24 h resulted in significant inhibitory effects on GH release from one tumour over a range of concentrations tested (IGF-II 0·5–10 nmol/l). Addition of human GH-releasing factor (hGRF)(1–44) (20 nmol/l) for 4 and 24 h resulted in stimulation of GH release by five tumours. Two tumours demonstrated significant inhibitory effects of IGF-II on GRF-stimulated GH release (tumour 2: 24 h, IGF-II 1–5 nmol/l; tumour 3; 4 h, IGF-II 5 nmol/l; 24 h, IGF-II 0·5–50 nmol/l). These data emphasize the heterogeneity of somatotrophinomas in terms of their response to modulators of GH secretion. IGF-II does not appear to have a modulatory role on GH release by most somatotrophinomas. Journal of Endocrinology (1991) 129, 447–451

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Influence of Two Garlic-Derived Compounds, Propyl Propane Thiosulfonate (PTS) and Propyl Propane Thiosulfinate (PTSO), on Growth and Mycotoxin Production by Fusarium Species In Vitro and in Stored Cereals

Toxins ◽

10.3390/toxins11090495 ◽

2019 ◽

Vol 11 (9) ◽

pp. 495 ◽

Cited By ~ 4

Author(s):

Kalliopi Mylona ◽

Esther Garcia-Cela ◽

Michael Sulyok ◽

Angel Medina ◽

Naresh Magan

Keyword(s):

Water Activity ◽

Fusarium Species ◽

Fungal Growth ◽

Inhibitory Effect ◽

Effective Control ◽

Mycotoxin Production ◽

Potential Use ◽

Stimulation Of

Two garlic-derived compounds, Propyl Propane Thiosulfonate (PTS) and Propyl Propane Thiosulfinate (PTSO), were examined for their efficacy against mycotoxigenic Fusarium species (F. graminearum, F. langsethiae, F. verticillioides). The objectives were to assess the inhibitory effect of these compounds on growth and mycotoxin production in vitro, and in situ in artificially inoculated wheat, oats and maize with one isolate of each respectively, at different water activity (aw) conditions when stored for up to 20 days at 25 °C. In vitro, 200 ppm of either PTS or PTSO reduced fungal growth by 50–100% and mycotoxin production by >90% depending on species, mycotoxin and aw conditions on milled wheat, oats and maize respectively. PTS was generally more effective than PTSO. Deoxynivalenol (DON) and zearalenone (ZEN) were decreased by 50% with 80 ppm PTSO. One-hundred ppm of PTS reduced DON and ZEN production in wheat stored at 0.93 aw for 20 days, although contamination was still above the legislative limits. Contrasting effects on T-2/HT-2 toxin contamination of oats was found depending on aw, with PTS stimulating production under marginal conditions (0.93 aw), but at 0.95 aw effective control was achieved with 100 ppm. Treatment of stored maize inoculated with F. verticilliodies resulted in a stimulation of total fumonsins in most treatments. The potential use of such compounds for mycotoxin control in stored commodities is discussed.

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ANTIBODY PRODUCTION IN VITRO

Journal of Experimental Medicine ◽

10.1084/jem.127.4.661 ◽

1968 ◽

Vol 127 (4) ◽

pp. 661-674 ◽

Cited By ~ 5

Author(s):

Gilmour Harris

Keyword(s):

Antibody Production ◽

Small Proportion ◽

Specific Activity ◽

Specific Antigen ◽

High Specific Activity ◽

Inhibitory Effects ◽

Spleen Cells ◽

Dividing Cells ◽

Stimulation Of

The effect of high specific activity thymidme-3H on proliferation and antibody production, using the hemolytic plaque-forming technique, by spleen cell suspensions in vitro from rabbits killed after a boost of SRC's has been studied. High specific activity thymidine-3H inhibited the proliferative ay well as the antibody response to antigen, and it was conduded that this was the result of the incorporation of radioactive 3H into the nuclei of dividing cells which were synthesizing antibody in these cultures. The stimulation of the rate of DNA synthesis by specific antigen could be correlated with the ability of antigen to maintain antibody production, as measured by the specific hemolytic plaque-forming technique, above levels found in control cultures, incubated without antigen. Radioautographic studies of PFC's in vitro showed that the majority of the cells arose from the DNA-synthesizing population of cells in these cultures, confirming the conclusions from the results of the inhibitory effects of high specific-activity thymidine-3H on PFC's. It was found that these PFC's, labeling with thymidine-14C, formed only a small proportion of all the cells labeled in this way in these cultures. The postulation was made that antigen, in vitro, provided a stimulation for cell proliferation in the responsive population of rabbit spleen cells, but that only a small proportion of this population could be induced by antigen to synthesize antibody.

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