Inhibitory Effect Of Substances Research Articles

Assessment of the Substance Antioxidative Profile by Hyaluronan, Cu(II) and Ascorbate.

In the minireview presented here, the authors discuss the evaluation of inhibitory effect of substances in the phases of initiation and propagation of high-molar-mass hyaluronan oxidative degradation. The experimental approach should be considered as original since on using a simple experimental assay it is possible to prove both the so-called “preventive” and “chain-breaking” antioxidant activity of investigated water-soluble endo- or exogenous substances.

Method for Bacterial Growth and Ammonia Production and Effect of Inhibitory Substances in Disposable Absorbent Hygiene Products

The purpose of this study was to evaluate a pragmatic laboratory method to provide a technique for developing incontinence products better able to reduce malodor when used in the clinical setting. Bacterial growth and bacterially formed ammonia in disposable absorbent incontinence products was measured by adding synthetic urine inoculated with bacteria to test samples cut from the crotch area of the product. The inhibitory effect's of low pH (4.5 and 4.9) and 3 antimicrobial substances-chlorhexidine, polyhexamethylene biguanide (PHMB), and thymol-at 2 concentrations each, were studied. From the initial inocula of 3.3 log colony-forming units per milliliter (cfu/mL) at baseline, the bacterial growth of the references increased to 5.0 to 6.0 log cfu/mL at 6 hours for Escherichia coli, Proteus mirabilis, and Enterococcus faecalis. At 12 hours there was a further increase to 7.0 to 8.9 log cfu/mL. Adjusting the pH of the superabsorbent in the incontinence product from 6.0 to pH 4.5 and pH 4.9 significantly (P < .05) inhibited the bacterial growth rates, in most cases, both at 6 and 12 hours. The effect was most pronounced at pH 4.5. Chlorhexidine had significant (P < .05) inhibitory effect on E. coli and E. faecalis, and at 12 hours also on P. mirabilis. For PHMB and thymol the results varied. At 6 hours, the ammonia concentration in the references (pH 6.0) was 200 to 300 ppm and it was 1500 to 1600 ppm at 8 hours. At pH 4.5, no or little ammonia production was measured at 6 and 8 hours. At pH 4.9, there was a significant reduction (P < .01). Chlorhexidine and PHMB exerted a significant (P < .01 or P < .001) inhibitory effect on ammonia production at both concentrations and at 6 and 8 hours. Thymol 0.003% and 0.03% showed inhibitory effect at both 6 hours (P < .01 or P < .001) and at 8 hours (P < .05 or P < .001). The method described in this study can be used to compare the ability of various disposable absorbent products to inhibit bacterial growth and ammonia production. This technique, we describe, provides a pragmatic method for assessing the odor-inhibiting capacity of specific incontinence products.

Hydrogen Sulfide and Platelets: A Possible Role in Thrombosis.

Platelets are circulating blood elements with key roles in haemostasis and thrombosis. Platelets are activated by a range of stimuli including exposed subendothelial components. Haemostasis also depends upon the effects of inhibitory substances, including the gasotransmitter nitric oxide whose effects on platelets are well documented. Evidence is also emerging to suggest that H2S is generated enzymatically by platelets and can impact their function. Exposure of platelets to H2S from slow-release compounds inhibits aggregation and exerted anti-thrombotic effects in vivo. The mechanisms by which H2S impacts platelet function and the importance of interactions between H2S and other gasotransmitters remain unclear. H2S is therefore emerging as a potentially important regulator of platelet activation and thrombosis. Further study is required to evaluate its importance as a regulator of platelet physiology and associated pathological conditions such as myocardial infarction and stroke.

Effect of Inhibitory Substances on &lt;I&gt;Microbiospora&lt;/I&gt; Isolated from Soil under Cultivation of &lt;I&gt;Curcuma Longa&lt;/I&gt; L.

Problem statement: Soil Pollution is major problem because different types of pesticides are used to control plant pest. The residual component of pesticide diffuses into the soil. It is necessary to check whether actinomycetes degrade these components and control the soil pollution. Approach: In Ayurved system of medicine the rhizome portion of Curcuma longa L. was used as an anti-inflammatory and antiseptic. Antimicrobial substances released from these plants diffuse into the surrounding soil area of the plant. Actinomycete which grow in these area were resistant to these substances. Hence considerable attention had been given in studying the effect of inhibitory substances on actinomycetes especially Microbiospora isolated from soil under cultivation of Curcuma longa L. Results: The present study deals with effect of inhibitory substances like dettol, phenol, sodium azide, lysol and crystal violet. The results were recorded on the basis of presence or absence of growth. All five isolates of Microbiospora were found sensitive against dettol. One strain of Microbiospora was found resistant to phenol. Conclusion/Recommendations: From the study performed we conclude that Microbiospora which is resistant to phenol and other inhibitory substances can be used to degrade the residual components of pesticide which are released into the soil. It may have better option to prevent soil pollution.

An Assay for Detecting Neutralization of Rotavirus Infection by Quantitative Determination of VP6 Protein Fluorescence Intensity

Previous rotavirus infection studies used the focus reduction assay extensively to evaluate cellular responses to viral infection, but this technique has a number of limitations. In this study, we developed a simplified, accurate rotavirus infection assay to evaluate the effects of inhibitory substances on rotavirus infection in vitro by measurement of the fluorescence intensities of stained cells.

Immunomodulatory role of substance P in the wall lizard Hemidactylus flaviviridis: An in vitro study

Present in vitro investigation for the first time in ectotherms demonstrated the immunomodulatory role of substance P in the wall lizard Hemidactylus flaviviridis. Substance P inhibited the percentage phagocytosis and phagocytic index of lizard splenic phagocytes. Inhibitory effect of substance P was completely blocked by NK-1 receptor antagonist spantide I, indicating the NK-1 receptor mediated action. Further, NK-1 receptor-coupled downstream signaling cascade involved in controlling phagocytosis was explored using inhibitors of adenylate cyclase (SQ 22536) and protein kinase A (H-89). Both the inhibitors, in a concentration-related manner decreased the suppressive effect of substance P on phagocytosis. In addition, substance P treatment caused an increase in intracellular cAMP level in splenic phagocytes. Taken together, it can be suggested that substance P via NK-1 receptor-coupled AC-cAMP-PKA pathway modulated the phagocytic activity of splenic phagocytes in wall lizards.

Determination of glucose by a kinetic method on a thin-layer chromatogram using the oxidation of 3,3′,5,5′-tetramethylbenzidine with hydrogen peroxide

The oxidation of 3,3',5,5'�tetramethylbenzidine with hydrogen peroxide in aqueous solutions in the presence of iron(II, III) was studied on the surface of chromatography paper and TLC plates following the general approach to the purposeful selection of indicator reactions in kinetic methods of analysis. Among the 17 studied model analytes, the strongest inhibitory activity was detected for benzoic acid and glucose. The inhibitory effect of substances is likely due to their interaction with hydroxyl radicals forming in the indicator reaction. The most intense signal of glucose was detected on the surface of silica. Glucose was detected as a light spot against the blue background ( Rf ~ 0.5). A procedure for the semiquantitative determination of glu� cose on a thinlayer chromatogram based on the dep endence of the reflectometerregistered value of the reflectance coefficient on the logarithm of the analyte concentration is proposed. In the range 3 × 10 -5 - 0.01 M, two concentrations of glucose differing by one half order of magnitude can be distinguished. The detection limit is 1 × 10 -5 M. The procedure was applied to the determination of glucose in beverages, saliva samples, and in a fructose preparation.

Intrathecal substance P (1–7) prevents morphine-evoked spontaneous pain behavior via spinal NMDA-NO cascade

Previous research has shown that injection of high-dose of morphine into the spinal lumbar intrathecal (i.t.) space of rats elicits an excitatory behavioral syndrome indicative of severe vocalization and agitation. Substance P N-terminal fragments are known to inhibit nociceptive responses when injected i.t. into animals. In this study, we investigated the effect of i.t. substance P (1–7) on both the nociceptive response and the extracellular concentrations of glutamate and nitric oxide (NO) metabolites (nitrite/nitrate) evoked by high-dose i.t. morphine (500 nmol). The induced behavioral responses were attenuated dose-dependently by i.t. pretreatment with the substance P N-terminal fragment substance P (1–7) (100–400 pmol). The inhibitory effect of substance P (1–7) was reversed significantly by pretreatment with [ d-Pro 2, d-Phe 7]substance P (1–7) (20 and 40 nmol), a d-isomer and antagonist of substance P (1–7). In vivo microdialysis analysis showed a significant elevation of extracellular glutamate and NO metabolites in the spinal cord after i.t. injection of high-dose morphine (500 nmol). Pretreatment with substance P (1–7) (400 pmol) produced a significant reduction on the elevated concentrations of glutamate and NO metabolites evoked by i.t. morphine. The reduced levels of glutamate and NO metabolites were significantly reversed by the substance P (1–7) antagonist (40 nmol). The present results suggest that i.t. substance P (1–7) may attenuate the excitatory behavior (vocalization and agitation) of high-dose i.t. morphine by inhibiting the presynaptic release of glutamate, and reducing NO production in the dorsal spinal cord.

The inhibitory effect of Substance P on HCO3- secretion from the guinea pig microperfused pancreatic ducts

Background. We have previously shown using sealed, non-perfused, ducts that Substance P (SP) inhibits HCO3-secretion by inhibiting Cl-dependant HCO3-efflux on the luminal membrane of the duct cell (Hegyi et al. Am J Physiol Cell Physiol 285: C268-C276, 2003). However, in that study we had no direct evidence that SP affected a luminal anion exchanger. To address this issue we examined the effects of luminal H2DIDS on the inhibitory effect of SP in microperfused ducts.

Bisindolylmaleimide reverses the inhibitory effects of substance P and phorbol ester on pancreatic ductal bicarbonate secretion in the guinea pig

Bisindolylmaleimide reverses the inhibitory effects of substance P and phorbol ester on pancreatic ductal bicarbonate secretion in the guinea pig

Bicuculline blocks the inhibitory effects of substance p but not vasoactive intestinal polypeptide on gastric motor function in the nucleus raphe obscurus of the rat

Bicuculline blocks the inhibitory effects of substance p but not vasoactive intestinal polypeptide on gastric motor function in the nucleus raphe obscurus of the rat

Neurotransmitters in caudate nucleus substantia nigra and dorsal vagal nucleus involved in inhibitory effect of substance P of caudate nucleus on gastric myoelectric activity and motility

Neurotransmitters in caudate nucleus substantia nigra and dorsal vagal nucleus involved in inhibitory effect of substance P of caudate nucleus on gastric myoelectric activity and motility

Antagonism of cholinergic nerve-mediated contractions by the sensory nerve inhibitory system in rat bronchi.

The purpose of this study was to examine the potential functional significance of the sensory nerve inhibitory system in modulating contraction. Tension development in response to electrical field stimulation (EFS) and exogenous acetylcholine was monitored in segments of intrapulmonary bronchi isolated from male Sprague-Dawley rats. Contractile responses to EFS were enhanced by desensitization of sensory nerves with capsaicin, by antagonizing neurokinin NK1 receptors with RP-67580, and by inhibition of cyclooxygenase with meclofenamate. Except for RP-67580, which had a slight inhibitory effect on acetylcholine-induced contractions, these interventions were without effect on contraction to acetylcholine. Incubation of capsaicin-desensitized airway segments with substance P attenuated contractions evoked by a half-maximal frequency of EFS by approximately 92%, whereas contractions elicited by a half-maximal concentration of acetylcholine were not affected. Contractile responses elicited by a lower concentration of acetylcholine were inhibited by approximately 50% by substance P. The inhibitory effect of substance P was blocked by RP-67580, meclofenamate, and epithelial denudation. We conclude that the sensory nerve inhibitory system modulates cholinergic contractions and thus plays a role in the regulation of airway smooth muscle tone.

The inhibitory effect of substance P on gastric motor function in the nucleus raphe obscurus is mediated via nitric oxide in the dorsal vagal complex

We have previously shown that substance P (SP), microinjected into the caudal nucleus raphe obscurus (nROb) of the rat decreases intragastric pressure via a vagally mediated pathway. Recent studies from this laboratory demonstrated that nitric oxide (NO) synthase is present in the dorsal vagal complex (DVC) and NO synthase blockade in the DVC of the rat with N G-nitro- l-arginine methyl ester ( l-NAME) evokes increases in intragastric pressure. Since the nROb controls gastric vagal outflow through the DVC, we tested the hypothesis that NO in the DVC is a mediator of inhibitory effects of SP on gastric motor function in the nROb. Substance P (135 pmol) was microinjected into the nROb 3–6 min after bilateral microinjections of l-NAME (45 nmol per site) into the DVC of chloraloseanesthetized rats were started. Changes in the area of the response for intragastric pressure on microinjection of SP after l-NAME did not differ from the effect of vehicle microinjected after l-NAME and were significantly lower when compared with the effect of SP microinjected after vehicle. We conclude that SP in the nROb releases NO in the DVC to mediate the inhibitory effect on intragastric pressure.

In vitro and in vivo evidence for a tachykinin NK 1 receptor antagonist effect of vapreotide, an analgesic cyclic analog of somatostatin

Vapreotide, a long-acting somatostatin analog, possesses an analgesic effect. The purpose of this work was to determine a tachykinergic involvement. Vapreotide reduced substance P-induced biting and scratching in mice. This inhibitory effect of substance P action was confirmed by experiments performed on the bronchial apparatus of guinea-pigs known to possess tachykinin NK 1 and NK 2 receptors. (i) Vapreotide reduced the substance P-induced plasmatic exudation. (ii) It inhibited selectively the tachykinin-dependent second contractile phase induced by electrical field stimulation of isolated bronchi. (iii) It shifted to the right the concentration-effect curve of substance P-induced contraction of isolated main bronchi. The peptide displaced [ 3H]substance P (IC 50 = 3.3 ± 1.8 × 10 −7 M) from guinea-pig bronchial tachykinin NK 1 sites. The displacement of [ 125I]neurokinin A, a specific tachykinin NK 2 receptor ligand, needed higher concentrations (IC 50 = 4.5 ± 0.6 × 10 −6 M). It is concluded that vapreotide possesses an antagonist activity on guinea-pig tachykinin NK 1 receptors; the involvement in its analgesic action is discussed.

The inhibitory effect of substance P on intragastric pressure in the nucleus raphe obscurus is mediated via nitric oxide in the dorsal val complex: [formula omitted] and P.J. Hornby. Department of Pharmacology, Louisiana State University Medical Center, New Orleans, LA

The inhibitory effect of substance P on intragastric pressure in the nucleus raphe obscurus is mediated via nitric oxide in the dorsal val complex: [formula omitted] and P.J. Hornby. Department of Pharmacology, Louisiana State University Medical Center, New Orleans, LA

Inhibitory effects of salmon calcitonin on the tail-biting and scratching behavior induced by substance P and three excitatory amino acids.

We have examined the effects of salmon calcitonin (SCT), injected into the cerebral ventricle (i.c.v.), on the tail-biting and scratching behavior induced by the intrathecal injection of different types of nociceptive agents, i.e., substance P, N-methyl-D-aspartate (NMDA), kainate (KA), and quisqualate (Quis). Tail-biting and scratching behavior induced by the 4 substances was significantly inhibited by SCT (i.c.v.) in the same manner: the dose-response curves were U-shaped, and the most effective dose was 0.1 IU/mouse in all cases. SCT did not, however, completely inhibit tail-biting and scratching behavior. At its most effective dose, the percent inhibition of substance P-, NMDA-, KA- and Quis-induced behavior were 77.9%, 40.2%, 49.4%, and 52.9%, respectively. These results suggest that SCT has the inhibitory effects of substance P- and glutamate receptor agonists-induced nociceptive response in vivo.

The inhibitory effect of substance P antagonist, CP-96,345, on the late discharges of nociceptive neurons in the rat superficial spinal dorsal horn

The effects of local spinal applications of the substance P antagonist, CP-96,345, on the electrically-evoked discharges of nociceptive neurons were examined in the superficial spinal dorsal horn of adult rats anesthetized with sodium pentobarbital. Extracellular single-unit recordings were made from lumbar spinal dorsal horn neurons which were excited by noxious mechanical stimulation and had early and late discharges evoked by A- and C-fiber inputs, respectively, following transcutaneous electrical stimulation. CP-96,345 was applied directly onto the surface of the spinal cord close to the recording sites. A dose of 50 nmol of CP-96,345 drastically inhibited the late discharges of 80% of neurons, without affecting early discharges significantly. This study demonstrated the specific inhibitory effect of CP-96,345 on the late discharges of a restricted population of spinal dorsal horn neurons. These results illustrate the important role of substance P in nociceptive transmission mediated by primary afferent C-fibers in normal acute pain.

Inhibitory effects of substance P analogs on the activation of GTP-binding regulatory proteins by receptors

Inhibitory effects of substance P analogs on the activation of GTP-binding regulatory proteins by receptors

Inhibitory effects of substance P analogs on the activation of GTP-binding regulatory proteins by receptors

Inhibitory effects of substance P analogs on the activation of GTP-binding regulatory proteins by receptors