PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “PROCAINE AND COMPOUNDS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources

Histamine receptor-independent muscle relaxation elicited by a series of histamine H2-receptor agonists on the isolated guinea pig duodenum: a study into the mechanism of action.

1. The histamine H2 receptor agonists, dimaprit, impromidine, amthamine, and several dimaprit- and impromidine-analogues were investigated for their spasmolytic activity on the guinea pig duodenum, precontracted with acetylcholine or KCl. 2. Almost all the H2 receptor agonists exerted a histamine H2 receptor-independent muscle relaxation, which was more evident on acetylcholine- than on KCl-precontracted preparations. 3. The relaxing activity of these compounds was independent of inhibitory receptors, like beta-adrenergic, GABA-ergic, serotoninergic, etc. Similarly, modifications of cyclic nucleotide metabolism and nitric oxide production did not appear to be involved. 4. The behavior of histamine H2-receptor agonists was shared only by the Na+-blocker procaine, the intracellular Ca2+-antagonist ruthenium red and, at least in terms of efficacy, by the protein kinase C inhibitor, chelerithrine. 5. This spasmolytic effect is probably due to an impairment of receptor-mediated depolarization at the plasma membrane level and/or an inhibitory activity on the protein kinase C-dependent activation of the contractile machinery. 6. Finally, our findings suggest that the histamine H2 receptor-independent muscle relaxation is a general feature shown by H2 receptor agonists endowed with different chemical structure and the putative spasmolytic "receptor" prefers a (substituted) thiazole over a (substituted) imidazole.

Animals↗

Inhibitory effects of magnolol on distal colon of guinea pig in vitro.

The influence of plant product magnolol (0-100 microM) on the contractile activity of isolated colonic muscle strips in guinea pig and related mechanism were investigated. Magnolol did not affect the base tone of colon muscle strips, but it dose-dependently inhibited 40 mM KCl-, 1 microM carbachol (CCh)- and 10 microM serotonin (5-HT)-induced contractions at concentrations higher than 10 microM. And also, magnolol inhibited the 5-HT- or CCh-induced muscle contraction in calcium-free buffer. Furthermore, magnolol inhibited the KCl-induced contraction under the condition of procaine. In addition, inhibition rate of nifedipine plus magnolol on muscle strips was lower than that of nifedipine alone. Moreover, magnolol dose-dependently decreased the velocity of pellet propulsion in the concentration range of 0.1-10 microM, and totally inhibited pellet propulsion at the concentration higher than 30 microM. Thus, it can be concluded that magnolol may 1) block receptor-operated cation channels and the voltage dependent Ca2+ channel, and 2) inhibit calcium release from the sarcolemmal membrane (SR) through blocking InsP3-sensitive and ryanodine-sensitive pathways. This explains, at least partially, that Cortex magnoliae officinalis exerts therapeutic effects on gastrointestinal disease through relaxation of GI tract smooth muscles.

Anesthetics, Local↗

Local anesthetics. Effect of pH on use-dependent block of sodium channels in frog muscle.

Sodium currents were studied under voltage clamp in the presence of neutral, amine, and quaternary local anesthetic compounds. Use-dependent block was observed as a cumulative depression of INa seen with repetitive depolarizing test pulses applied at frequencies of 2-10s-1. With quaternary QX-314, the time constant of use dependence was long, and with neutral benzocaine, very short. With lidocaine and procaine, increasing external pH (pHo) changed the time constant from long to short, but alterations of internal pH have no effect. Inactivation in Na channels was measured by the influence of prepulses on peak INa during test pulses. Single-stimulus inactivation curves were shifted more with lidocaine at high pHo than at low pHo, but inactivation curves measured during pulse trains with any of the drugs and at any pHo were strongly shifted. All measurements show that the drug-receptor reaction was slow for amine drugs at low pHo, as for quaternary drugs at any pHo, and fast for amine drugs at high pHo, as for neutral drugs at any pHo. The major effect of low pHo on amine drugs was to reduce the concentration of drugs in the fiber and to protonate drug molecules on the receptor, thus trapping them in the blocking position for a longer time. Direct effects of pH on the receptor seemed minimal.

Anesthetics, Local↗

Antagonism of calcium-induced contraction in potassium-depolarized rabbit detrusor muscle strips by dicyclomine hydrochloride and rociverine.

The musculotropic action of dicyclomine hydrochloride in bladder muscle has been attributed to its local anesthetic activity. In this study rabbit detrusor strips were depleted of calcium by incubation in Ca2+-free solution containing ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA). Contractions elicited by replacement of Ca2+ during depolarization with 80 mM K+ were only slightly affected by atropine or scopolamine but were antagonized in a noncompetitive manner by dicyclomine and rociverine (pD2' = 4.89 and 4.61, respectively). These contractions were also blocked with greater potency by nifedipine (pD2' = 8.50) and with lesser potency by lidocaine (pD2' = 2.52). Procaine was ineffective up to 1 mM. Comparison of the antagonism produced by dicyclomine and rociverine with that produced by nifedipine or lidocaine did not help to define the mechanism of the musculotropic drugs. However, as rociverine is not a local anesthetic and procaine was not effective, it appears that the "local anesthetic" property is not sufficient to explain the action of these musculotropic drugs.

Animals↗

[Search for agents with prolonged anesthetizing action (the neurolytic type of local anesthetizing action)].

Compounds that possess long-term anesthetic effect have been found among phenylethylamine derivatives substituted by O-alkyl (position 4) or O-benzyl (positions 2, 3 and 4) radicals. It was shown that these compounds compare very favourably with novocain, since their anesthetic effect exceeds 54.8 - 66.9-fold that produced by novocain. Such an effect is a consequence of neurolytic properties of the compounds synthesized.

Anesthetics, Local↗

Palytoxin induces a relatively non-selective cation permeability in frog sciatic nerve which can be inhibited by cardiac glycosides.

The effect of palytoxin (PTX) on compound resting potential and compound action potential of frog sciatic nerve was studied using the sucrose-gap technique. PTX irreversibly depolarized the compound resting potential and reduced the amplitude of the compound action potential. PTX evoked a marked depolarization when extracellular Na+ was replaced by Li+, Cs+ and the organic cations methylammonium, hydroxylammonium, and methylhydroxylammonium but not by tetramethylammonium, tetraethylammonium, choline or the divalent cations, Ca2+ and Ba2+. The maintained depolarization was not sensitive to inhibition by saxitoxin (300 nM) or procaine (10 mM). The depolarization was inhibited by ouabain or cymarin but not by the aglycon, strophanthidin. However, strophanthidin did antagonize the inhibitory action of cymarin which suggests that PTX and cardiac glycosides do not share an identical binding site but there may be some overlap. We conclude that in frog sciatic nerve, PTX interacts with the (Na+-K+) pump to induce the opening or formation of a relatively non-selective cation pore within or near the pump protein.

Acrylamides↗

Evaluation of certain veterinary drug residues in food. Fiftieth report of the joint FAO/WHO Expert Committee on Food Additives.

This report presents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of residues of certain veterinary drugs in food and to recommend maximum levels for such residues. The first part of the report considers the neurotoxicity of anthelminthics belonging to the avermectin and milbemycin classes of compounds and the evaluation policy of the Committee in establishing Maximum Residue Levels (MRLs) for veterinary drugs in food. A summary follows of the Committee's evaluations of toxicological and residue data on a variety of veterinary drugs: five anthelminthic agents (eprinomectin, febantel, fenbendazole, oxfendazole and moxidectin), seven antimicrobial agents (gentamicin, procaine benzylpenicillin, sarafloxacin, spectinomycin, chlortetracycline, oxytetracycline and tetracycline), three antiprotozoal agents (diclazuril, imidocarb and nicarbazin), one glucocorticosteroid (dexamethasone), one production aid (recombinant bovine somatotropins) and one tranquilizing agent (azaperone). Annexed to the report are a summary of the Committee's recommendations on these drugs, including Acceptable Daily Intakes and MRLs, and further toxicological studies and other information required.

Adrenal Cortex Hormones↗

Sulfhydryl oxidation induces rapid calcium release from sarcoplasmic reticulum vesicles.

Micromolar concentrations of cupric ion (Cu2+) and mercaptans such as cysteine, cysteamine, and homocysteine trigger large and rapid Ca2+ release from skeletal muscle sarcoplasmic reticulum (SR) vesicles. At the concentrations used, Cu2+ alone does not induce Ca2+ release nor does cysteine alone; both are required to induce Ca2+ release from SR. Cu2+ is known to catalyze the autooxidation of cysteine to its disulfide form cystine; Cu2+/mercaptan-induced Ca2+ release appears to be caused by Cu2+-catalyzed formation of a mixed disulfide between the exogenous mercaptan and a critical sulfhydryl on a transmembrane protein. In the oxidized state the SR is highly permeable to Ca2+. Supporting evidence for this interpretation is as follows. The order of Ca2+-releasing reactivity of the mercaptans is the same as the order in which these compounds undergo oxidation to disulfide forms in the presence of Cu2+. Ca2+ efflux induced by cysteine and Cu2+ can be reversed by the addition of the disulfide reducing agent dithiothreitol. Hypochlorous acid and plumbagin, both potential sulfhydryl oxidants, induce rapid Ca2+ efflux from SR vesicles; in addition, Cu2+, which catalyzes H2O2 oxidation of cysteine, enhances H2O2-induced release. Oxidation-induced Ca2+ release from SR can be partially reversed or blocked by ruthenium red or the local anesthetics procaine and tetracaine. The Ca2+ efflux rates are strongly Mg2+ dependent and are significantly higher in heavy SR than in light SR. These data suggest that the Ca2+ efflux thus induced is via the "Ca2+ release channel" and that the oxidation state of a critical sulfhydryl group on this protein may be the principal means by which the Ca2+ permeability of the SR is regulated in vivo.

Animals↗

Agents ameliorating or augmenting the nephrotoxicity of cisplatin and other platinum compounds: a review of some recent research.

Cisplatin (cis-diamminedichloroplatinum (II)) is an effective agent against various solid tumours. Despite its effectiveness, the dose of cisplatin that can be administered is limited by its nephrotoxicity. Hundreds of platinum compounds (e.g. carboplatin, oxaliplatin, nedaplatin and the liposomal form lipoplatin) have been tested over the last two decades in order to improve the effectiveness and to lessen the toxicity of cisplatin. Several agents have been tested to see whether they could ameliorate or augment the nephrotoxicity of platinum drugs. This review summarizes these studies and the possible mechanisms of actions of these agents. The agents that have been shown to ameliorate experimental cisplatin nephrotoxicity include antioxidants (e.g. melatonin, vitamin E, selenium, and many others), modulators of nitric oxide (e.g. zinc histidine complex), agents interfering with metabolic pathways of cisplatin (e.g. procaine HCL), diuretics (e.g. furosemide and mannitol), and cytoprotective and antiapoptotic agents (e.g. amifostine and erythropoietin). Only few of these agents have been tested in humans. Those agents that have been shown to augment cisplatin nephrotoxicity include nitric oxide synthase inhibitors, spironolactone, gemcitabine and others. Combining these agents with cisplatin should be avoided.

Animals↗

Influence of solvent properties on separation and detection performance in non-aqueous capillary electrophoresis-mass spectrometry of basic analytes.

The versatility of non-aqueous capillary electrophoresis (NACE) results mainly from the variety of physico-chemical properties of the different solvents. They provide solubility for a wide range of analytes, enable to control electrophoretic selectivity, but affect in some cases UV absorbance detection. The coupling of NACE to electrospray mass spectrometry (ESI-MS) allows to cope with the high UV cut-off of some CE relevant solvents (e.g., formamides). In this paper the pure organic solvents methanol, acetonitrile, dimethylsulfoxide, formamide, N-methylformamide and N,N-dimethylformamide are evaluated against water for the preparation of ammonium acetate electrolytes to separate the basic model substances 2-aminobenzimidazole, procaine, propranolol and quinine with NACE-MS. MS coupling is assisted with the sheath liquid water-isopropanol (1:4, v/v) with 0.1% formic acid. The goal of the paper is to assess the influence of the solvent on selectivity, separation speed, and peak efficiency for a given set of model compounds on a simple empirical basis. It should give the user an idea how the separation quality is changed when nothing but the running solvent is altered. The obtained efficiency results were discussed with respect to physico-chemical models described in literature (assuming longitudinal diffusion as the only source of band broadening), but no satisfying correlations with solvent properties could be traced. The feasibility of all six organic solvents for MS coupling was demonstrated and the influence of the separation solvent on the MS detection performance was compared. In the seven different solvents, the shortest run time was obtained with acetonitrile, the best peak resolution with the amphiprotic solvents (especially methanol) best peak efficiency with methanol and formamide, and the most sensitive ESI-MS detection with acetonitrile and methanol, but with only slight advantage to water.

Electrophoresis, Capillary↗

Central nervous system effects of local anaesthetic agents.

A review is given of an experimental study on cats where the influence of acid-base changes on central nervous system toxicity of local anaesthetic agents was studied. The conclusion of this study was that a respiratory acidosis increased the central nervous system toxicity of local anaesthetics and that the underlying metabolic conditions modified this increase. Thus a respiratory acidosis increased this toxicity more if it was based on a metabolic acidosis than on a metabolic alkalosis (Englesson, 1974; Englesson and Grevsten, 1974). An extended analysis is presented where automatic frequency analysis was performed on the e.e.g. recordings performed during the i.v. infusion of lignocaine, bupivacaine, L 134, HS 37 and its optical isomers. The preliminary results show that the electrical changes appearing in the e.e.g. from the start of the i.v. infusion until seizure activity were the same if this time interval was as short as 1 min or as long as 8 min. It also revealed remarkable individual differences between agents, for instance lignocaine displaying marked electrical changes already in the first third of this time period where bupivacaine showed no changes until shortly before seizures.

Acid-Base Equilibrium↗

Potassium hydroxide solution 10% for the fast hydrolysis of esters for analysis.

The applicability of a five-minute hydrolysis method with 10% potassium hydroxide in an alcohol-water (80-20) mixture was investigated for the quantitative determination of certain esters (aspirin, benzocaine, benzyl benzoate, methyl paraben, phenyl salicylate, procaine hydrochloride, propyl paraben, salicylanilide and 0-salicylsalicylic acid) and salicylamide. The results indicate that the method is satisfactory for all but methyl paraben and propyl paraben.

Benzocaine↗

Intradermal anaesthesia: comparison of several compounds.

OBJECTIVE: To compare the efficacy of different local anaesthetics to produce intradermal anaesthesia for venous cannulation and the discomfort associated with skin infiltration. DESIGN: Randomized, double blind study. SETTING: Induction room of a university hospital. PATIENTS: Convenience sample of 600 patients (18-65 years; ASA I-II) scheduled for elective surgery. INTERVENTIONS: Patients received one of six preparations: 0.9% saline, 1% prilocaine (Xylonest), 1% lidocaine (Xylocain), 1% mepivacaine-1 (Meaverin), 1% mepivacaine-2 (Scandicain), 1% procaine (Novocain). A skin wheal was raised on the dorsum of the hand by injecting 0.1 ml intradermally and 0.1 ml subcutaneously via a 27-g hypodermic needle. 60 seconds later an 18-g intravenous cannula was passed through that skin wheal into a vein. MEASUREMENTS: A visual analog scale (VAS) for pain (0 = no pain/10 = most pain imaginable) was used to assess pain elicited by raising the skin wheal and inserting the cannula. MAIN RESULTS: With regard to analgesic potency all five local anaesthetics were comparable (mean VAS-score 1.7-2.09) and effective when compared to 0.9% saline (mean VAS-score 4.2; P < 0.001). Infiltration pain was least with mepivacaine-1 (mean VAS-score 1.0; P < 0.001) and highest with procaine (mean VAS score 2.7; P < 0.001). CONCLUSIONS: Of the local anaesthetics tested, Mepivacaine-1 is the drug of choice for skin infiltration as its injection elicits least discomfort.

Adolescent↗

Coloured complexes of all-trans-retinal with benzocaine and other local anaesthetics.

Coloured Schiff base complexes with lambda max values of 500 nm or above were formed between the visual pigment all-trans-retinal and the local anesthetics procaine (lambda max = 533 nm), benzocaine (4-amino-benzoic acid ethyl ester, lambda max = 535 nm), 3-amino-benzoic acid ethyl ester (lambda max = 500 nm) and 2-amino-benzoic acid ethyl ester (lambda max = 509 nm) in methanol acidified with HCl. The anaesthetics lidocaine and urethane failed to form coloured compounds with lambda max values greater than 500 nm under the same conditions. The relevance of these observations to the effect of anaesthetics on the visual pigments is discussed.

Anesthetics, Local↗