PURPOSE: To investigate the in vitro response of MC3T3-E1 osteoblastic cells to X-ray in the presence and absence of 2 deoxy-D-glucose (2-DG) and quercetin (QCT). MATERIALS AND METHODS: The MC3T3-E1 cells were cultured in an alpha-MEM supplemented with 5 mM 2-DG or 10 micrometer QCT and then the cells were incubated for 12 h prior to irradiation with 2, 4, 6, and 8 Gy using a linear accelerator (Mevaprimus, Germany) delivered at a rate of 1.5 Gy/min. At various times after the irradiation, the cells were processed for the analyses of proliferation, viability, cytotoxicity, and mineralization. RESULTS: Exposure of the cells to X-ray inhibited the tritium incorporation, 3-(4, 5-dimethylthiazol-2yl-)-2, 5- diphenyl tetrazolium bromide (MTT)-reducing activity, and alkaline phosphatase (ALP) activity, and caused cytotoxicity and apoptosis in a dose-dependent manner of the X-ray. This effect was further apparent on day 3 and 7 after the irradiation. RA+2-DG showed the decrease of DNA content, cell viability, and increase of cytotoxicity rather than RA. ALP activity increased on day 7 and subsequently its activity dropped to a lower level. 2-DG suppressed the calcium concentration, but visual difference of number of calcified nodules between RA and RA+2-DG was not noticed. RA+QCT showed the increase of DNA content, cell viability, but decrease of cytotoxicity and subG1 stage cells in the cell cycle, and increased calcified nodules in von Kossa staining rather than the RA. ALP activity showed significant increases on day 7 and subsequently its activity dropped to a lower level. CONCLUSION: The results showed that the 2-DG acted as a radiosensitizing agent and QCT acted as a radioprotective agent respectively in the irradiated MC3T3-E1 osteoblast-like cells.
Alkaline Phosphatase ; Apoptosis ; Calcium ; Cell Cycle ; Cell Survival ; Deoxyglucose* ; DNA ; Osteoblasts* ; Particle Accelerators ; Quercetin* ; Tritium

As it has been reported that the depolarization induced acetylcholine (ACh) release is modulated by activation of presynaptic A1 adenosine heteroreceptor and various lines of evidence suggest the A2 adenosine receptor is present in the hippocampus. The present study was undertaken to delineate the role of adenosine receptors on the hippocampal ACh release. Slices from the rat hippocampus were equilibrated with (3H)choline and then the release amount of the labelled product, (3H)ACh, which was evoked by electrical stimulation (rectangular pulses, 3 Hz, 2 ms, 24 mA, 5 V/cm-1, 2 min), was measured, and the influence of various adenosine receptor-related agents on the evoked tritium outflow was investigated. And also, the drug-receptor binding assay was performed in order to confirm the presence of A1 and A2 adenosine receptors in the rat hippocampus. N-ethylcarboxamidoadenosine (NECA), a potent adenosine receptor agonist with nearly equal affinity at A1 and A2 adenosine receptors, in concentrations ranging from 1apprx30 muM, decreased the electrically-evoked (3H)ACh release in a concentration-dependent manner without affecting the basal rate of release. And the effect of NECA was significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 2 micrometer), a selective A1 adenosine receptor antagonist, but was not influenced by 3,7-dimethyl-1-propargylxanthine (DMPX, 5 micrometer, a specific A2 adenosine receptor antagonist. N6-Cyclopentyladenosine (CPA), a selective A1 adenosine receptor agonist, in doses ranging from 0.1 to 10 micrometer, reduced evoked (3H)ACh release in a dose-dependent manner without the change of the basal release. And the effect of CPA was significantly inhibited by 2 micrometer DPCPX treatment. 2-P-(2-carboxyethyl)-phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS-21680C), a potent A2 adenosine receptor agonist, in concentrations ranging from 0.1 to 10 micrometer, did not alter the evoked ACh release. In the drug-receptor binding assay, the binding of (3H)2-chloro-N6-Cyclopentyladenosine ((3H)CCPA) to the- A1 adenosine receptor of rat hippocampal membranes was inhibited by CPA (Ki = 1.22 nM), NECA (Ki=10.17 nM) and DPCPX (Ki-161.86 nM), but not by CGS-21680C (Ki=2,380 nM) and DMPX (Ki-22,367 nM). However, the specific binding of (3H)CGS-21680C to the A2 adenosine receptor was not observed. These results suggest that the A1 adenosine heteroreceptor play an important role in evoked ACh release, but the presence of A2 adenosine receptor is not confirmed in this study.
Acetylcholine* ; Adenosine* ; Adenosine-5'-(N-ethylcarboxamide) ; Animals ; Electric Stimulation ; Hippocampus* ; Membranes ; Rats* ; Receptors, Purinergic P1* ; Tritium

As it has been reported that the depolarization-induced norepinephrine (NE) release is modulated by activation of presynaptic A-1-adenosine heteroreceptor and various lines of evidence indicate that A-2-adenosine receptor also presents in hippocampus, and that the adenosine effect is magnesium dependent, the present study was undertaken to delineate the role of adenosine receptors in the modulation of hippocampal NE release. Slices from the rat hippocampus were equilibrated with (3H)-NE and the release of the labelled product, (3H)-NE, was evoked by electrical stimulation (3 Hz, 5 V cm-1, 2 ms, rectangular pulses), and the influence of various agents on the evoked tritium outflow was investigated. N-6-cyclopentyladenosine (CPA), in concentrations ranging from 0.1 to 10 micrometer, decreased the (3H)-NE release in a dose-dependent manner without changing the basal rate of release, and these effects were significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 2 micrometer) treatment. When the magnesium concentration was reduced to 0.4 mM or completely removed, the evoked NE release increased along with decreased basal rate of release. In contrast, increasing the magnesium concentrations to 2.4 and 4 mM, decreased the evoked NE release. The CPA effects on evoked NE release were reduced by magnesium removal, but potentiated by 2.4 mM magnesium in the medium. 5-(N-cyclopropyl)-carboxamodiadenosine (CPCA, 1 & 10 micrometer), an A-2-agonist, decreased the evoked tritium outflow, and this effect was also abolished by DPCPX pretreatment. CGS, a powerful A-2-agonist, did not affect the evoked NE release. However, the effects of CPCA and CGS on evoked NE release were significantly increased by pretreatment of DPCPX in the magnesium-free medium. These results indicate that inhibitory effect of A-1-adenosine receptor on NE release is magnesium-dependent, and A-2-receptor may be present in the rat hippocampus.
Adenosine ; Animals ; Electric Stimulation ; Hippocampus* ; Magnesium* ; Norepinephrine* ; Rats* ; Receptors, Purinergic P1 ; Tritium

The systemic administration of low doses of dopamine(DA) agonist, such as apomorphine, LY 171555 and n-propyl norapomorphine induces penile erection and yawning in rats. Such a response is apparently mediated by the stimulation of central DA receptors of the D2 type and studies have suggested a localization of this action to the paraventricular nucleus(PVN) of the hypothalamus. We have investigated the effect of serum testosterone level on the apomorphine induced penile erection and yawning and the effect of serum testosterone level on the in vitro binding of [3H]N -n -propyl norapomorphine ( [3H]NPA) in cryostat from the paraventricular nucleus (PVN) of the hypothalamus in rats. All rats of control group demonstrated an erectile response and yawning behavior. Castrated rats did not have erections and had diminished yawning but responded normally after testosterone administration. In autoradiography, castration elicited significant reduction in the specific binding of 0.25 nM [ 3H] NPA to D2 receptor sites in paraventricular nucleus, but after testosterone replacement the specific binding increased above control level. Testosterone was necessary to the maintenance of a specific dopaminergic centrally mediated erection and it's blood level affects the binding properties of tritium NPA from paraventricular nucleus of hypothalamus. In these study we could suggest one aspect of androgen action on penile erection and the rationale of androgen replacement therapy.
Animals ; Apomorphine ; Autoradiography ; Castration ; Dopamine ; Hypothalamus ; Male ; Models, Animal* ; Paraventricular Hypothalamic Nucleus ; Penile Erection* ; Rats* ; Testosterone ; Tritium ; Yawning

The aim of this study was to investigate the role of the 5-HT receptors in acetylcholine (ACh) release from the striatum. Slices from the rat striatum and synaptosomes were incubated with [3H]-choline and the release of the labelled products was evoked by electrical (3 Hz, 2 ms, 5 V/cm, rectangular pulses, 2 min) and potassium-stimulation (25 mM), respectively, and the influence of various serotonergic drugs on the evoked tritium outflows was investigated. Serotonin decreased the electrically-evoked ACh release in striatum in a concentration-dependent manner without the change of basal release. In hippocampal and entorhinal cortical slices, serotonin did not affect the evoked and basal release of ACh, but, at large dose (30 microM) decreased the evoked ACh release in hippocampus. 2,5-Dimethoxy-4-iodoamphetamine (DOI), a specific 5-HT 2A/2C agonist, decreased evoked ACh release in the striatum. CGS-12066A (5-HT 1B agonist), m-chlorophenyl-biguanide (5-HT 3 agonist) and 5-[(dimethyl -amino)methyl]-3-(1-methyl-1H-indol-3-yl)-1,2,4-oxadiazole (5-HT 3 antagonist) did not affect the evoked and basal ACh release in all tissues. Ritanserin, a specific 5-HT 2A/2C antagonist, blocked the inhibitory effects of serotonin and DOI, whereas, ketanserin, an another type of specific 5-HT 2A/2C antagonist did not affect the inhibitory effects of serotonin and DOI. In striatal synaptosomal preparation, serotonin and DOI did not affect the K +-evoked ACh release. These findings suggest that ritanserin-sensitive 5-HT 2A/2C receptors located in the soma and/or axons of the striatal cholinergic neurons play a important role in ACh release.
Acetylcholine* ; Animals ; Axons ; Carisoprodol ; Cholinergic Neurons ; Hippocampus ; Ketanserin ; Rats* ; Receptors, Serotonin* ; Ritanserin ; Serotonin Agents ; Serotonin* ; Synaptosomes ; Tritium

The influence of thyroxine upon n the cardiac uptake of catecholamines was investigated in rabbits. A single injection of thyroxine(1.0m/kg) into rabbits did not affect the concentration of myocardial catecholamines. However, this dose of thyroxine greatly increased the cardiac uptake of catecholamine following injection of 2.0mg of norepinephrine as compared to that of untreated normal animals and it remained elevated for several hours. Similarly thyroxine also enhanced the accumulation of myocardial catecholamines following administration of dopa(60-80mg/kg) and epinephrine(1.0-1.5mg/kg).
Animal ; Catecholamines/metabolism* ; Epinephrine/metabolism ; Heart/drug effects* ; Male ; Myocardium/metabolism* ; Norepinephrine/metabolism ; Rabbits ; Thyroxine/pharmacology* ; Tritium

OBJECTIVETo study the relationship between tissue quantitative distribution and pharmacokinetics of 3H-achyranthes bidentata ecdysterone and the channel-tropism of herbal drugs in mice.

METHOD3H-achyranthes bidentata ecdysterone was used as a tracer agent and injected into mice by the caudal vein. In 36 hours, the contents of the tracer agent of samples involving 9 different tracing phases and organ or tissue were determined in order to observe the dynamic quantitative distribution and excretion and pharmacokinetics of 3H-achyranthes bidentata ecdysterone and to understand the channel-tropism of herbal drugs achyranthes bidentata.

RESULT3H-achyranthes bidentata ecdysterone of same organs in different tracing phases and the contents of 3H-achyranthes bidentata ecdysterone in same tracing phases of different organs were significantly different (P<0.01). 3H-achyranthes bidentata ecdysterone was mainly distributed, in the liver, kidney, adrenal gland, small intestine and lung. The concentration-time profiles of achyranthes bidentata ecdysterone in rats injected into mice by the caudal vein were shown to fit a two-compartment open model with half-lives of (778.65 +/- 12.36) min, the elimination of achyranthes bidentata ecdysterone from plasma was found to be in accord with linear kinetics.

CONCLUSIONThe above mentioned selective distribution of 3H-achyranthes bidentata ecdysterone basically coincides with the meridian affinity and zang fu selection of the traditional Chinese medicine drug Achyranthes bidentata. This study will provide a scientific basis for the channel-tropism of A. bidentata.

Achyranthes ; chemistry ; Animals ; Drugs, Chinese Herbal ; metabolism ; pharmacokinetics ; Ecdysterone ; metabolism ; pharmacokinetics ; Isotope Labeling ; Male ; Meridians ; Mice ; Organ Specificity ; Tissue Distribution ; Tritium ; chemistry

The authors designed to separate, purify and determine the monosaccharide composition of the polysaccharide from Cordyceps militaris, and study its effect on reverse cholesterol transport in vivo by isotope tracing assay. Polysaccharides were separate and purify by ion exchange column Q-sepharose Fast Flow and size exclusion column Sephacryl S200HR; the molecular weight and monosaccharide composition of the polysaccharides were determined by high performance gel permeation chromatography and high performance liquid chromatography coming with pre-column derivation, respectively. Finally, three purified polysaccharides CMBW1, CMBW2 and CMYW1 were obtained, their total carbohydrate contents were 87%, 89%, 95%, respectively; their protein contents were 6.5%, 1.3%, 2.8%, respectively; their molecular weights were 772.1, 20.9, 13.2 kDa, respectively; CMBW1 was composed of mannose, glucosamine, rhamnose, glucuronic acid, glucose, galactose and arabinose with a molar ratio of 7.25: 0.17: 1.29: 0.23: 6.30: 11.08: 0.79; CMBW2 was composed of mannose, glucosamine, galactose and arabinose with a molar ratio of 2.40: 0.16: 2.92: 0.24; CMYW1 was composed of mannose, glucosamine, glucuronic acid and glucose with a molar ratio of 0.59: 0.57: 0.45: 25.61. Polysaccharide at 50 mg x kg(-1) could significantly improve the transport of 3H- cholesterol to blood and excretion from feces. All of the three purified polysaccharides CMBW1, CMBW2 and CMYW1 were heteropolysaccharide; and they could improve reverse cholesterol transport in vivo, the underlying mechanisms are being studied.
Animals ; Biological Transport ; drug effects ; Cholesterol ; metabolism ; Chromatography, High Pressure Liquid ; instrumentation ; methods ; Cordyceps ; chemistry ; Mice ; Monosaccharides ; analysis ; isolation & purification ; Polysaccharides ; chemistry ; isolation & purification ; pharmacology ; Tritium

As it has been reported that the depolarization induced acetylcholine (ACh) release is modulated by activation of presynaptic A-1 adenosine heteroreceptor and various evidence suggest that indicate the A-2 adenosine receptor is present in the striatum, this study was undertaken to delineate the role of adenosine receptors on the striatal ACh release. Slices from the rat striatum were equilibrated with (3H)choline and then the release amount of the labelled product, (3H)ACh, which was evoked by electrical stimulation (rectangular pulses, 3 Hz, 2 ms, 24 mA, 5 Vcm-1, 2 min), was measured, and the influence of various agents on the evoked tritium outflow was investigated. And also, quantitative receptor autoradiography and drug-receptor binding assay were performed in order to confirm the presence and characteristics of A-1 and A-2 adenosine receptors in the rat striatum. Adenosine (10 ~ 100 micrometer) and N-6-cyclopentyladenosine (CPA, 1 ~ 100 micrometer) decreased the (3H)ACh release in a dose-dependent manner without changing the basal rate of release in the rat striatum. The reducing effects of ACh release by adenosine and CPA were abolished by 8-cyclopentyl-1,3-dipropy-lxanthine (DPCPX, 2 micrometer), a selective A-1 adenosine receptor antagonist, treatment. The effect of adenosine was potentiated markedly by 3,7-dimethyl-1-propargylxanthine (DMPX, 10 micrometer), a specific A-2 adenosine receptor antagonist. 2-P-(2-carboxyethyl)phenethylamimo-5'-N- ethylcarboxamidoadenosine hydrochloride (CGS-21680C), in concentrations ranging from 0.01 to 10 micrometer, a recently introduced potent A-2 adenosine receptor agonist, increased the(3 H)ACh release in a dose related fashion without changing the basal rate of release. These effects were completely abolished by DMPX (10 micrometer). In autoradiogaphy experiments, (3H)2-chloro-N-6-cyclopentyladenosine ((3 H)CCPA) bindings were highly localized in the hippocampus and the cerebral cortex. Additionally, lower levels of binding were found in the striatum. However, (3H)CGS-21680C bindings were highly localized in the striatal region with the greatest density of binding found in the caudate nucleus and putamen. Lower levels of binding were also found in the nucleus accumbens and olfactory tubercle. In drug-receptor binding assay, binding of (3H)CCPA to A-1 adenosine receptors of rat striatal membranes was inhibited by CPA (K-i = 1.6nM) and N-ethylcarboxamidoadenosine (NECA, K-i = 12.9 nM), but not by CGS-21680C (K-i = 2609.2 nM) and DMPX (K-i = 19,386 nM). In contrast, (3H)CGS-21680C binding to A-2 adenosine receptors was inhibited by CGS-21680C (K-i = 47.6 rim) and NECA (K-i = 44.9 nM), but not by CPA (K-i = 2099.2 nM) and DPCPX (K-i = 19,207 nM). The results presented here suggest that both types of A-1 and A-2 adenosine heteroreceptors exist and play an important role in ACh release in the rat striatal cholinergic neurons.
Acetylcholine* ; Adenosine* ; Adenosine-5'-(N-ethylcarboxamide) ; Animals ; Autoradiography ; Caudate Nucleus ; Cerebral Cortex ; Cholinergic Neurons ; Electric Stimulation ; Hippocampus ; Membranes ; Nucleus Accumbens ; Olfactory Pathways ; Putamen ; Rats* ; Receptors, Purinergic P1* ; Tritium

A single dose of 3H-norcantharidin solution was intragastrically given, blood, tissues, urine and feces were collected as scheduled, and radioactivity in these samples was determined by tritium tracing method to investigate the pharmacokinetics, tissue distribution and excretion of norcantharidin in Kunming mice. The pharmacokinetic characteristics of norcantharidin were evaluated by DAS version 2.0. The blood concentration reached to maximum 0. 5 h after intragastric administration. The radioactivity in tissues was high in small intestine, gallbladder, stomach, adrenal gland, kidney, heart and uterus 15 minutes after administration, descending with time, and high in gallbladder, adrenal gland and uterus 3 hours post dosing. The 24 h accumulative excretion ratio of urine and feces were 65.40% and 1.33% respectively. 3H-norcantharidin was easily absorbed after orally given to mice, the radioactivity was high and existed for a long-time in gallbladder, adrenal gland and uterus, and low but also existed for a long-time in large intestine, thymus and fat tissue. 3H-norcantharidin was declined quickly in small intestine, stomach, kidney and heart, and occurred rarely in brain. Norcantharidin was excreted mainly by urinary route and seldom in feces, which may be the cause of the urinary stimulation side effects observed. Because the radioactivity measured were the sum of 3H labeled norcantharidin and its metabolites, further studies on the disposition of norcantharidin in mammal animals, on the separation or identification of metabolites and, if any, on their activities, are fairly needed.
Administration, Oral ; Animals ; Antineoplastic Agents ; administration & dosage ; chemistry ; pharmacokinetics ; urine ; Bridged Bicyclo Compounds, Heterocyclic ; administration & dosage ; chemistry ; pharmacokinetics ; urine ; Feces ; chemistry ; Female ; Male ; Mice ; Molecular Structure ; Random Allocation ; Tissue Distribution ; Tritium