The objectives of this study were to develop optimal analytic methods for detecting urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) and thiocarbamide simultaneously and to evaluate the usefulness of these metabolites to a biological exposure index (BEI) for carbon disulfide (CS2) exposure. For this experiment, synthesized TTCA and thiocarbamide were used. The synthesized TTCA was identified by infrared spectrophotometer, nuclear magnetic resonance spectrometer and thin layer chromatography. The recovery rates of both metabolites were calculated to find the optimum analytical method. The amounts of urinary TTCA and thiocarbamide were measured by using an ultraviolet detector connected to high performance liquid chromatography (HPLC) after the administration of CS2 (350, 700 mg/kg) into Sprague-Dawley rats intraperitoneally. The maximum absorbance wave lengths for TTCA and thiocarbamide were 272 and 236 nm, respectively. Ethyl acetate extraction with NaCl as a salting-out reagent was used as a simultaneous extraction method for these metabolites. HPLC conditions for these metabolites included using a NH2 column, 50 mM KH2PO4: acetonitrile (85:15) and pH 3. Excreted amounts of urinary TTCA and thiocarbamide were increased significantly following CS2 administration. TTCA, which was already adopted as a BEI for CS2 by the American Conference of Governmental Industrial Hygienists (ACGIH), seems to be a more useful BEI for CS2 exposure than thiocarbamide. However further studies are needed to increase analytical efficiency before thiocarbamide can be adopted as a BEI and to apply this analytic method for simultaneous analysis of these metabolites in workers exposed to CS2.
Animal ; Carbon Disulfide/pharmacology* ; Environmental Exposure* ; Rats ; Rats, Sprague-Dawley ; Thiazoles/urine* ; Thiourea/urine* ; Urea/urine*

The aim of the present paper was to study the role of sodium calcium exchanger (NCX) in the generation of action potentials (APs) in cardiomyocytes during early developmental stage (EDS). The precisely dated embryonic hearts of C57 mice were dissected and enzymatically dissociated to single cells. The changes of APs were recorded by whole-cell patch-clamp technique before and after administration of NCX specific blockers KB-R7943 (5 μmol/L) and SEA0400 (1 μmol/L). The results showed that, both KB-R7943 and SEA0400 had potent negative chronotropic effects on APs of pacemaker-like cells, while such effects were only observed in some ventricular-like cardiomyocytes. The negative chronotropic effect of KB-R7943 on ventricular-like cardiomyocytes was accompanied by shortening of AP duration (APD), whereas such an effect of SEA0400 was paralleled by decrease in velocity of diastolic depolarization (Vdd). From embryonic day 9.5 (E9.5) to E10.5, the negative chronotropic effects of KB-R7943 and SEA0400 on ventricular-like APs of embryonic cardiomyocytes gradually disappeared. These results suggest that, in the short-term development of early embryo, the function of NCX may experience developmental changes as evidenced by different roles of NCX in autorhythmicity and APs generation, indicating that NCX function varies with different conditions of cardiomyocytes.
Action Potentials ; Animals ; Calcium/metabolism* ; Mice ; Myocytes, Cardiac/metabolism* ; Sodium/metabolism* ; Sodium-Calcium Exchanger ; Thiourea/pharmacology*

OBJECTIVETo study the scavenging effects of Lu-Duo-Wei, thiourea, superoxide dismutase, and sodium azide on carbon disulfide-induced generation of hydroxyl radicals.

METHODSPhenanthroline-CuSO(4)-Vit C-H(2)O(2) chemiluminescence system (PHEN system) containing alcohol was established to probe the influence of various concentrations of carbon disulfide on hydroxyl radicals emission intensity and the scavenging effects of Lu-Duo-Wei and other antioxidants on carbon disulfide-induced hydroxyl radicals were observed.

RESULTSThe average emission intensity of PHEN system containing alcohol appeared lower luminescence [91.03 x 10(3) (cp6s)] and longer time (75 s) to get the peak than the system without alcohol [96.11 x 10(3) (cp6s), 55 s]. The specific scavenger of hydroxyl radical, thiourea, showed clear inhibitory effect on the system. Carbon disulfide in the range of 40 - 160 mmol/L promoted the generation of hydroxyl radical, however, this effect could be efficiently inhibited by thiourea. 160 mmol/L carbon disulfide in PHEN system without copper seemed as an activator to promote the luminescence, while in PHEN system withdrawing phenanthroline appeared some weak action of luminescence agent at low concentration. Meanwhile, Lu-Duo-Wei may efficiently scavenge hydroxyl radicals induced by carbon disulfide in PHEN system but superoxide dismutase and sodium azide had little effects on the system.

CONCLUSIONCarbon disulfide may induce PHEN system to generate hydroxyl radicals and Lu-Duo-Wei may efficiently scavenge these free radicals and play an important role in protection against oxidative injury induced by carbon disulfide.

Carbon Disulfide ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Free Radical Scavengers ; pharmacology ; Hydroxyl Radical ; antagonists & inhibitors ; chemistry ; metabolism ; Luminescent Measurements ; Phenanthrolines ; chemistry ; Superoxide Dismutase ; pharmacology ; Thiourea ; pharmacology

AIMTo get some novel potent compounds with NOS inhibitory activity, a series of new compounds of isothioureas derived from 1,2,3,4-tetrahydroisoquinoline were synthesized.

METHODS1,2, 3,4-Tetrahydroisoquinol-2-yl was introduced into the structure of isothioureas, the NOS inhibitory activity of the new compounds synthesized were measured.

RESULTS AND CONCLUSIONTwenty-two isothiourea derivatives of [alkyl(or aryl) imino] (1,2,3,4-tetrahydroisoquinol-2-yl) methyl alkyl thioethers (I) and S-alkyl-1-phenyl-3-[4-(1,2,3,4-tetrahydroisoquinol-2-yl) methane] phenyl isothioureas (II) were synthesized from thioureas by S-alkylation with alkyl halides, and their structures were identified by IR, 1H NMR, MS and elemental analysis. The preliminary biological test showed that the part of type I (1-9 and 1-13) had higher NOS inhibitory activity than that the control aminoguanidine (AG), but the type II had weak ability to inhibit NOS.

Molecular Structure ; Nitric Oxide Synthase ; antagonists & inhibitors ; metabolism ; Stereoisomerism ; Tetrahydroisoquinolines ; chemistry ; Thiourea ; analogs & derivatives ; chemical synthesis ; chemistry ; pharmacology

Animals ; Disease Models, Animal ; Liver ; parasitology ; Mice ; Mice, Inbred BALB C ; Schistosomiasis japonica ; immunology ; Thiourea ; analogs & derivatives ; pharmacology

AIMTo synthesize a series of 2-arylimino-4-thiazolidone derivatives and 2-imidazolino [2,3-b]-4-thiazolidone in order to get some novel potent compounds with nitric oxide synthases (NOS) inhibitory activity.

METHODSThe target compounds were prepared by reaction of N-chloroacetyl-1,2,3,4-tetrahydroisoquinoline or N-chloroacetylphthalimide with substituted thioureas, their NOS inhibitory activity were measured.

RESULTS AND CONCLUSIONThe 15 new compounds were synthesized and most of the reaction yields were over 65%. The structures of new compounds were identified by IR, 1H NMR, MS and elemental analyses. Bioassay indicated that, most of 15 new compounds synthesized had confirmed bioactivities inhibition against NOS.

Molecular Structure ; Nitric Oxide Synthase ; antagonists & inhibitors ; metabolism ; Structure-Activity Relationship ; Thiazoles ; chemical synthesis ; chemistry ; pharmacology ; Thiourea ; analogs & derivatives

The present study was aimed to investigate the positive inotropic mechanism of carbachol (CCh) on rat ventricular myocytes. The effects of CCh on L-type calcium current (I(Ca,L)) and Na(+)/Ca(2+) exchange current (I(Na/Ca)) were investigated in isolated rat ventricular myocytes. After loading myocytes with Fura-2/AM, electrically triggered Ca(2+) transient and cell shortening in single myocyte were measured simultaneously using ion imaging system with charge-coupled device (CCD) camera. CCh (100 mumol/L) increased I(Na/Ca) in forward mode from (1.18 +/- 0.57) pA/pF in the control group to (1.65 +/- 0.52) pA/pF (P<0.01) and that in reverse mode from (1.11 +/- 0.49) pA/pF in the control group to (1.53 +/- 0.52) pA/pF (P<0.01), respectively. CCh had no effect on I(Ca,L). The stimulatory effect of CCh on I(Na/Ca) was blocked by application of atropine, a non-selective M muscarinic receptor antagonist, and methoctramine, a selective M(2) muscarinic receptor antagonist. CCh (100 mumol/L) increased cell shortening from (3.00 +/- 0.67) mum in the control group to (3.55 +/- 1.21) mum. Ca(2+) transient was also increased from 203.8 +/- 50.0 in the control group to 234.8 +/- 64.3 in 100 mumol/L CCh group. KB-R7943, a selective inhibitor of reverse mode Na(+)/Ca(2+) exchange, did not change the baseline level of cell shortening and Ca(2+) transient, while completely abolished CCh-induced increments of both Ca(2+) transient and cell shortening. CCh increased cell shortening and Ca(2+) transient in the presence of nicardipine, indicating that the positive inotropic effect of CCh was through activation of Na(+)/Ca(2+) exchange. Calcium sensitivity was not changed by CCh. Both atropine and methoctramine abolished the positive inotropic effects of CCh, demonstrating that CCh induced positive inotropism via the M(2) muscarinic receptor. The results suggest that CCh increases cell contraction and Ca(2+) transient in rat ventricular myocytes. This positive inotropic effect of CCh is through activation of reverse mode Na(+)/Ca(2+) exchange, and M(2) receptors are involved in mediating CCh-induced contraction.
Animals ; Calcium ; Carbachol ; pharmacology ; Heart Ventricles ; Male ; Myocardial Contraction ; Myocytes, Cardiac ; drug effects ; Rats ; Receptor, Muscarinic M2 ; Receptors, Muscarinic ; drug effects ; Sodium ; Sodium-Calcium Exchanger ; Thiourea ; analogs & derivatives

OBJECTIVETo investigate the mechanisms of histamine on chronic epilepsy induced by pentylenetetrazole (PTZ).

METHODSTo induce chemical kindling, a subconvulsive dose (35mg/kg) of PTZ was ip injected every 48 h in rats. Behavior changes were observed for 30 min after every injection of PTZ.

RESULTIp injection of histidine or icv injection of clobenpropit inhibited the development of kindling induced by PTZ, presenting prolonged latency for myoclonic jerks and clonic generalized seizures and depressed seizure stages in a dose-dependent manner. H(3)receptor agonist, immepip, and histidine decarboxylase, alpha-fluoromethylhistidine reversed the ameliorating effect of clobenpropit on seizure development in a dose-dependent manner.

CONCLUSIONBrain histamine plays an important role in protection against myoclonic jerks and clonic generalized clonic seizures and its action may be via H(3)receptor.

Animals ; Brain ; physiology ; Chronic Disease ; Dose-Response Relationship, Drug ; Epilepsy ; chemically induced ; Histamine ; physiology ; Histidine ; pharmacology ; Imidazoles ; pharmacology ; Male ; Pentylenetetrazole ; pharmacology ; Piperidines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Thiourea ; analogs & derivatives ; pharmacology

Basing on the market multi-target antitumor agent sorafenib, a series of sixteen 4-[4-(2-methyl-aminoacyl-pyridyl)]oxylphenyl aryl thiourea derivatives were designed and synthesized. Their structures were identified by the spectra of 1H NMR, MS and elemental analysis. The evaluation of antitumor bioactivities in vitro was done by MTT method. It was shown that the synthesized compounds had antitumor activities and compounds 1a, 1d, 1i and 1j showed better or equal antitumor activity on sorafenib.
Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Molecular Structure ; Niacinamide ; analogs & derivatives ; chemical synthesis ; chemistry ; pharmacology ; Phenylurea Compounds ; chemical synthesis ; chemistry ; pharmacology ; Thiourea ; analogs & derivatives ; chemical synthesis ; chemistry ; pharmacology

OBJECTIVETo define the effects of Astragalus membranaceus on the atrial dynamics and ANP secretion in the perfused beating rabbit atria.

METHODThe experiments have been done in isolated perfused beating rabbit atria. ANP was measured by radioimmunoassay in the atrial perfusate in real-time base.

RESULTA. membranaceus (2.0, 2.5, 3.0 g L(-1)) could increase atria stroke volume from (694.70 +/- 0.01) microL g(-1) (P<0.05) to (1,003.00 +/- 8.80) microL g(-1) (P<0.001); (1,120.00 +/- 17.71) microL g(-1) and (1,195.00 +/- 8.21) microL g(-1) (P<0.001), respectively, and its could difference increase atrial pulse pressure from (0.82 +/- 0.01) kPa to (0.86 +/- 0.01) kPa (P<0.01); (0.96 +/- 0.01) kPa (P<0.001) and (1.02 +/- 0.01) kPa (P<0.001), respectively; A. membranaceus obviously increased rabbit atrial dynamics with dose-dependent manner. Simultaneously, A. membranaceus inhibited ANP secretion. Nifedipine (1.0 micromol L(-1)), a L-type Ca2+ channel inhibitor, and KB-R 7943 (10.0 micromol L(-1)), an inhibitor of reversed Na+ -Ca2+ exchanger, blocked the effects of A. membranaceus-induced augmentation of atrial dynamics but failed to modulation the inhibition of A. membranaceus on ANP secretion.

CONCLUSIONA. membranaceus increases the atrial dynamics via Na+ -Ca2+ exchanger and L-type Ca2+ channel and negatively modulates ANP secretion in beating rabbit atria.

Animals ; Astragalus membranaceus ; chemistry ; Atrial Natriuretic Factor ; metabolism ; secretion ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Female ; Heart Atria ; drug effects ; metabolism ; secretion ; Male ; Myocardial Contraction ; drug effects ; Nifedipine ; pharmacology ; Rabbits ; Radioimmunoassay ; Thiourea ; analogs & derivatives ; pharmacology