Genetic diversity of Lactobacillus delbrueckii isolated from raw milk in Hokkaido, Japan

Lactic acid bacteria (LAB) play important roles in acid production and flavor formation in fermented dairy products. Lactic acid bacteria strains with distinct characteristics confer unique features to products. Diverse LAB have been identified in raw milk and traditional fermented milk prepared from raw milk. However, little is known about LAB in raw milk in Japan. To preserve diverse LAB as potential starters or probiotics for future use, we have isolated and identified various kinds of LAB from raw milk produced in Japan. In this study, we focused on Lactobacillus delbrueckii, one of the most important species in the dairy industry. We identified L. delbrueckii subspecies isolated from raw milk in Hokkaido, Japan, by analyzing intraspecific diversity using 4 distinct methods, hsp60 cluster analysis, multilocus sequence analysis, core-genome analysis, and whole-genome analysis based on average nucleotide identity. The subspecies distribution and a new dominant subset of L. delbrueckii from raw milk in Japan were revealed. The discovery of new strains with different genotypes is important for understanding the geographic distribution and characteristics of the bacteria and further their use as a microbial resource with the potential to express unconventional flavors and functionalities. The strains identified in this study may have practical applications in the development of fermented dairy products.

Depression Promotes the Onset of Irritable Bowel Syndrome through Unique Dysbiosis in Rats

Background/Aims

Although studies using conventional animal models have shown that specific stressors cause irritable bowel syndrome (IBS), it is unclear whether depression itself causes IBS. Our aim was to establish a rat model to determine if depression itself promotes the onset of IBS and to elucidate the role of gut microbiota in brain-gut axis pathogenesis during coincident depression and IBS.

Methods

Rat models of depression were induced using our shuttle box method of learned helplessness. Visceral hypersensitivity was evaluated by colorectal distension (CRD) to diagnose IBS. Gut microbiota compositions were analyzed using high-throughput sequencing. In the subanalysis of rats without depression-like symptoms, rats with posttraumatic stress disorder (PTSD) were also examined.

Results

The threshold value of CRD in depressed rats was significantly lower than that in control rats. Microbial community analysis of cecal microbiota showed that the relative abundance of Clostridiales incertae sedis, the most prevalent microbe, was significantly lower in depressed rats than in control rats. The distribution pattern of the microbiota clearly differed between depressed rats and control rats. Neither visceral hypersensitivity nor the composition of gut microbiota was altered in rats with PTSD-like phenotypes.

Conclusions

Our rat model of depression is useful for clarifying the effect of depression on IBS and suggests that depression itself, rather than specific stressors, promotes the onset of IBS. Further, we provided evidence that various psychiatric diseases, viz., depression and PTSD, are associated with unique gut microbiota profiles, which could differentially affect the onset and progression of coincident IBS.

α1-Adrenoceptor Subtypes in the Rat Ventricular Muscle

Scatchard analyses of [3H]prazosin binding in rat ventricular muscle membranes showed biphasic curves, which identified α1High- and α1Low-affinity sites. The α1High-affinity site was completely inhibited by 1 μm phenoxybenzamine. The displacement potencies of α1-adrenergic antagonists were characterized by [3H]prazosin binding to α1High. and α1Low-affinity sites in the absence and presence of 1 μm phenoxybenzamine. The affinities of most chemicals for α1Low-affinity sites were significantly lower than those for α1High-affinity sites, but WB-4101 (2-(2,6-dimethoxy-phenoxyethyl)aminomethyl-1,4-benzodioxane), arotinolol, cinanserin, nifedipine, and p-aminoclonidine had the same affinities for both α1Low- and α1High-affinity sites. These results show that two α1-adrenoceptor subtypes, α1High- and α1Low-affinity, are present in the rat heart, and that there are physical variations in α1-adrenoceptor binding sites, based on their selectivity to antagonists.

Binding of [3H]Haloperidol to Dopamine D2 Receptors in the Rat Striatum

The present study was designed to examine the properties of [3H]haloperidol binding to dopamine D2-receptors in rat striatum membranes, displacement potencies of various chemicals and differences between the affinities of various chemicals and two new 5-hydroxytryptamine (5-HT2) receptor antagonists, MCI-9042, (±)-2-(dimethylamino)-1-[[o-(m-methoxyphenetyl)phenoxy]methyl]ethyl hydrogen succinate hydrochloride and one of its metabolites. The plots of specific binding for the striatum membranes obtained from the Scatchard analysis using [3H]haloperidol were monophasic when nonspecific binding was determined with 10 μm chlorpromazine, and the Kd and Bmax values were 7·42±1·03 Nm and 1·58±0·20 pmol (mg protein)−1 (n= 10), respectively. The displacement potencies of D2 receptor, 5- HT2 receptor, histamine H1-receptor, and adrenoceptor antagonists were characterized by [3H]haloperidol binding to D2 receptors. The pKi values of a new antiplatelet agent, MCI-9042, and its metabolite were 5·02 and 5·53, respectively, and these values were lower than those of the D2-receptor antagonists, fluphenazine, spiperone, haloperidol, prochlorperazine, chlorpromazine, thioridazine, and sulpiride. They were also lower than the pKi values of the 5-HT2-receptor antagonists, pirenperone, ketanserin, methysergide, and mianserin. We conclude that the binding site of [3H]haloperidol in the rat striatum is the D2 receptor, that MCI-9042 and its metabolite have lower affinities for D2 receptors than for 5-HT2 receptors, and that this radioreceptor assay is useful for assessing the affinities of various agents.

α1-Adrenoceptor Subtypes in Bovine Prostate

The object of this study was to examine the existence and characteristics of α1-adrenoceptor subtypes in the bovine prostate using the radioligand binding assay method. [3H]Prazosin was used as the radioligand and its binding sites in bovine prostate were classified into two subtypes. One subtype showed a high affinity (α1High, Kd: 101·1 Pm and Bmax: 11·8 fmol (mg protein)−1) and the other had a low affinity (α1Low, Kd: 3371·4 Pm and Bmax: 50·5 fmol (mg protein)−1). Although the same pKi values of clorethylclonidine, p-aminoclonidine, benoxathian and dibenamine to both α1High and α1  Low binding sites in bovine prostate tissue were observed, other α1 antagonists used in this study had different pKi values for the two α1-adrenoceptor subtypes. The existence and binding characteristics of α1-adrenoceptor subtypes in bovine prostate were clarified. It is possible that agents selective for one site may contribute to the development of better drugs for the treatment of bladder outlet obstructions of men with benign prostatic hyperplasia.

Urinary excretion of the main metabolites of methamphetamine, includingp-hydroxymethamphetamine-sulfate andp-hydroxymethamphetamine-glucuronide, in humans and rats

The urinary concentrations of the main metabolites of methamphetamine (MA), specifically p-hydroxymethamphetamine-sulfate (p-OHMA-Sul) and p-hydroxymethamphetamine-glucuronide (p-OHMA-Glu), were directly measured in MA users and rats using an optimized LC-ESI MS method. The concentrations of the two conjugates in 50 MA human users' urine ranged from 0.09 to 88.6 microM (0.02-21.7 microg ml-1) for p-OHMA-Sul and from <0.05 to 7.13 microM (<0.02-2.43 microg ml-1) for p-OHMA-Glu; the ratios of sulfate to glucuronide (S/G ratios) ranged from 2.2 to 37.1 (13.8+/-8.1). The results demonstrate that the sulfation is quantitatively more important than glucuronidation for the conjugation of p-OHMA in humans. The urinary concentration time-dependency in two MA users also revealed that the conjugates were mostly excreted in urine within 3 days post-intake. In contrast, in rat, almost all of the conjugated p-OHMA (>99%) was excreted as the glucuronide in urine. These findings confirm that a large species variation exists in the conjugation of p-OHMA between humans and rats.

Isolation, identification and excretion profile of the principal urinary metabolite of the recently banned designer drug 1-(3-trifluoromethylphenyl)piperazine (TFMPP) in rats

The metabolism of 1-(3-trifluoromethylphenyl)piperazine (TFMPP), a recently banned designer drug, in rats was studied by analysing its urinary metabolites. p-Hydroxy-TFMPP (p-OH-TFMPP) was isolated and identified as the main metabolite by using nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry and high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI MS). The time-course excretion profiles of TFMPP and p-OH-TFMPP in rats were investigated following a single intraperitoneal dosing of 5 mg kg(-1) TFMPP by using an optimized analytical procedure that combined solid-phase extraction and LC-ESI MS techniques. The cumulative amount of p-OH-TFMPP excreted within the first 48 h reached approximately 64% of the dose, of which 70% was the glucuronide conjugated form. The cumulative amount of parent TFMPP excreted was less than 0.7% of the dose. The results suggest that p-OH-TFMPP would be the most relevant metabolite to be detected for TFMPP exposure in the forensic and clinical analysis of human urine.

Metabolism of the recently encountered designer drug, methylone, in humans and rats

The urinary metabolites of methylone in humans and rats were investigated by analysing urine specimens from its abuser and after administrating to rats with gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-electrospray ionization mass spectrometry (LC-ESI MS), using authentic standards. The time-course excretion profiles of methylone and its three metabolites in rats were further investigated after a single intraperitoneal dosing of 5 mg kg-1 methylone hydrochloride. Two major metabolic pathways were revealed for both humans and rats as follows: (1) side-chain degradation by N-demethylation to the corresponding primary amine methylenedioxycathinone (MDC), partly conjugated; and (2) demethylenation followed by O-methylation of either a 3- or 4-OH group on the benzene ring to produce 4-hydroxy-3-methoxymethcathinone (HMMC) or 3-hydroxy-4-methoxymethcathinone (3-OH-4-MeO-MC), respectively, mostly conjugated. Of these metabolites, HMMC was the most abundant in humans and rats. The cumulative amount of urinary HMMC excreted within the first 48 h in rats was approximately 26% of the dose, and the amount of the parent methylone was not more than 3%. These results demonstrate that the analysis of HMMC will be indispensable for proof of the use of methylone in forensic urinalysis.

Urinary excretion of selegiline N-oxide, a new indicator for selegiline administration in man

1. The metabolism of selegiline (SG) has been studied by investigating the time-course of urinary excretion of SG and its metabolites using high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI MS) in combination with solid-phase extraction. 2. The excretion profiles of SG and its four major metabolites, selegiline-N-oxide (SGO), N-desmethylselegiline (DM-SG), methamphetamine (MA) and amphetamine (AP), were investigated in six healthy volunteers after oral administrations of SG hydrochloride in a single dose of 2.5 or 7.5mg, and a repeat twice-daily dose of 5.0 mg day(-1) (for 3 days). 3. The cumulative amount of SGO excreted within approximately the first 8-12h was comparable with MA, and the amount in the first 72 h was 2.0-7.8 times larger (2.8-13.2% of the dose) than that of DM-SG. 4. These results demonstrate that SGO can be used in place of DM-SG, which is known to be a main specific metabolite of SG, as a new indicator for the discrimination of SG use compared with MA abuse.

[Activities of thymidylate synthase and dihydropyrimidine dehydrogenase in patients with colorectal cancer]

Between 1998 and 2001, 82 colorectal cancers were resected in our hospital. The activities of TS and DPD were evaluated. TS activities in tumor tissues were significantly higher than in normal tissue, but the DPD activities had no significant difference between them. TS and DPD showed a correlation between normal and tumor tissues in stage III or IV patients. The TS value of patients with recurrence tended to be higher than that of patients with no recurrence. Especially in stage I or II patients with recurrence, who were administered 5-FU before recurrence, the TS value was significantly higher than in non-treated patients. In stage III or IV patients, it was considered that DPD prevention was important for 5-FU to effectively prevent TS. The TS value might be a new prospective risk factor for recurrence. Moreover, TS and DPD would be the index of biological malignancy.

Determination of plasma bromvalerylurea and its main metabolite by a simple high-performance liquid chromatographic method and quantitation of bromide by energy dispersive X-ray spectrometry in carbon tetrachloride-intoxicated rats

In the present study, small volumes of plasma were used for the measurement of bromvalerylurea (BVU), its metabolite, 3-methylbutyrylurea (MVU), and bromide in carbon tetrachloride (CCl4)-treated rats by HPLC-UV and energy dispersive X-ray spectrometry. A liquid-liquid extraction system was also investigated. BVU and MVU were extracted from 100 microl plasma samples in a single-step involving deproteination with 1 M hydrochloric acid using ethenzamide as internal standard. Samples were separated by HPLC in an acetonitrile-8 mM potassium dihydrogenphosphate buffer (35:65, v/v) mobile phase at a flow-rate of 0.4 ml/min on a 15 cm octadecylsilyl column at room temperature. Analytes were detected at a wavelength of 210 nm. The limits of quantitation for BVU, MVU and bromide are 0.1, 0.1 and 50 microg/ml, respectively. The intra-day accuracies over the range of concentrations were 95.8 to 121.1%, 97.2 to 119.7% and 96.2 to 105.8% for BVU, MVU and bromide, respectively. The inter-day accuracies were 97.7 to 115.1%, 98.3 to 111.6% and 98.3 to 102.9% for BVU, MVU and bromide, respectively. The absolute recoveries using tert.-butyl methyl ether are 96-98% for BVU and 95-98% for MVU. The decline in the plasma concentrations of BVU in olive oil-treated rats fitted a one-compartment model and the plasma MVU level reached a peak at around 1.5-2 h and then decreased gradually. The elimination of BVU in CCl4 (1 ml/kg)-treated rats was delayed and MVU production was less than that in the olive oil-treated group. However, there was no difference in the plasma levels of bromide between CCl4-treated rats and control rats. rights reserved.

Simultaneous determination of selegiline-N-oxide, a new indicator for selegiline administration, and other metabolites in urine by high-performance liquid chromatography-electrospray ionization mass spectrometry

In order to discriminate selegiline (SG) use from methamphetamine (MA) use, the urinary metabolites of SG users have been investigated using high-performance liquid chromatography (HPLC)-electrospray ionization mass spectrometry (HPLC-ESI-MS). Selegiline-N-oxide (SGO), a specific metabolite of SG, was for the first time detected in the urine, in addition to other metabolites MA, amphetamine (AP) and desmethylselegiline (DM-SG). A combination of a Sep-pak C18 cartridge for the solid-phase extraction, a semi-micro SCX column (1.5 mm I.D.x 150 mm) for HPLC separation and ESI-MS for detection provided a simple and sensitive procedure for the simultaneous determination of these analytes. Acetonitrile-10 mM ammonium formate buffer adjusted to pH 3.0 (70:30, v/v) at a flow-rate of 0.1 ml/min was found to be the most effective mobile phase. Linear calibration curves were obtained over the concentration range from 0.5 to 100 ng/ml for all the analytes by monitoring each protonated molecular ion in the selected ion monitoring (SIM) mode. The detection limits ranged from 0.1 to 0.5 ng/ml. Upon applying the scan mode, 10-20 ng/ml were the detection limits. Quantitative investigation utilizing this revealed that SGO was about three times more abundant (47 ng/ml, 79 ng/ml) than DM-SG in two SG users' urine samples tested here. This newly-detected, specific metabolite SGO was found to be an effective indicator for SG administration.

Column-switching high-performance liquid chromatography-electrospray ionization mass spectrometry for identification of heroin metabolites in human urine

In order to prove heroin (DAM) use, a simple, rapid and sensitive analytical method has been established by combining semi-microcolumn HPLC, a column switching technique and electrospray ionization mass spectrometry (ESI-MS). Urine samples were directly introduced to the system, and endogenous urinary constituents were removed by using on-line column switching solid-phase extraction with a strong cation-exchange (SCX) cartridge column (2.0 mm I.D. x 10 mm). Heroin and its metabolites enriched on the top of the column were then successfully analyzed with excellent separation by use of a SCX semi-microcolumn (1.5 mm I.D. x 150 mm), accompanied by ESI mass spectral detection. The proposed conditions are as follows: mobile phase, 10 mM ammonium acetate (pH 6.0)-acetonitrile (30:70, v/v) (for main separation) and 30 mM ammonium acetate (for trapping); flow-rates, 120 microl/min (for main separation) and 200 microl/min (for trapping); capillary voltage, +4.5 kV; cone voltage, 50 V. Linear calibration curves were obtained in the selected ion monitoring (SIM) mode using protonated molecular ions (m/z 370 for DAM, m/z 328 for MAM and m/z 286 for MOR) over the concentration ranges from 10 to 1000 ng/ml for morphine (MOR) and 1-100 ng/ml for DAM and 6-acetylmorphine (MAM). The detection limits were 0.1-3 ng/ml. Upon applying the scan mode, 2-30 ng/ml were the detection limits. The present HPLC-ESI-MS method was successfully applied to the determination of opiates in users' urine samples.

Discrimination of dimethylamphetamine and methamphetamine use: simultaneous determination of dimethylamphetamine-N-oxide and other metabolites in urine by high-performance liquid chromatography-electrospray ionization mass spectrometry

A simple and sensitive method by high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) has been investigated for the simultaneous determination of dimethylamphetamine (DMA), its specific yet labile main metabolite dimethylamphetamine-N-oxide (DMAO), and other metabolites, methamphetamine (MA) and amphetamine (AP), in urine. A combination of Bond Elut SCX columns for the solid-phase extraction of urine and a semi-micro SCX column for LC separations provided satisfactory results. The use of acetonitrile/5mM ammonium acetate buffer adjusted to pH 4 (65:35, v/v) as the mobile phase at a flow rate of 0.2 mL/min was found to be the most effective. The detection limits were 5 ng/mL for DMAO, 10 ng/mL for DMA and MA, and 50 ng/mL for AP in the SIM mode.

A case of serial homicide by injection of succinylcholine

The abstract of this paper was presented at the 14th Meeting of the International Association of Forensic Sciences, Tokyo in 1996. We report a bizarre criminal case of suspected serial homicide by injection of a muscle relaxant (succinylcholine). Five victims were found buried in a rural area. In two victims showing moderate decomposition (about three months after death), intense pulmonary oedema with pleural effusion was observed. Evidence of a puncture site was found in one of the victims. Succinylcholine could not be detected in the victims, but was identified in a syringe found near the corpses. The 40-mg ampule dose of succinylcholine administered intramuscularly to the victims, possibly causing prolonged apnea, was considered to be at least around the minimum lethal dose, although the combined effect of the sedation with hypnotics also used was not negligible.

Determination of ethyl glucuronide, a minor metabolite of ethanol, in human serum by liquid chromatography-electrospray ionization mass spectrometry

A rapid and sensitive determination procedure using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) has been developed for the determination of ethyl glucuronide (EtG) in human serum. Samples were precipitated with methanol, centrifuged and the supernatant was evaporated to dryness followed by reconstitution with distilled water. As mobile phase 30 mM ammonium acetate-acetonitrile (30:70, v/v) was utilized. The base peak observed at m/z 221 was the [M-H]- ion of EtG, which was detectable in satisfactory sense. The detection limit was 0.03 microg/ml in the selected ion monitoring mode. A calibration graph constructed for EtG in serum gave good linearity over the range from 0.1 to 25 microg/ml. This paper also presents the application of this LC-ESI-MS procedure to the analysis of authentic serum samples.

Determination of alkylmethylphosphonic acids, the main metabolites of organophosphorus nerve agents, in biofluids by gas chromatography-mass spectrometry and liquid-liquid-solid-phase-transfer-catalyzed pentafluorobenzylation

A simple gas chromatography-mass spectrometry (GC-MS) procedure has been developed for the main metabolites of organophosphorus nerve agents, alkylmethylphosphonic acids (AMPAs; alkyl = Et, i-Pr, and pinacolyl) in biofluids via extractive pentafluorobenzylation. The derivatization was carried out under liquid-liquid-solid-phase-transfer conditions using a polymer-bound tri-n-butylmethylphosphonium bromide as a catalyst. AMPAs in aqueous samples were semiquantitatively extracted into a small-volume organic layer as their pentafluorobenzyl derivatives at pH 4.5 (85 degrees C). Sample pretreatments for urine, serum, and saliva were each examined to minimize matrix interference. The detection limits of APMAs by electron-impact ionization GC-MS were around 50 ng/mL and 2.5-10 ng/mL in the full-scan and selected-ion monitoring modes, respectively. In order to detect trace-level AMPAs, negative-ion chemical ionization (NICI) was also employed to enhance sensitivity. The detection limits of AMPAs in biofluids were typically 60 pg/mL by GC-NICI-MS.

On-line solid-phase extraction liquid chromatography-continuous flow frit fast atom bombardment mass spectrometric and tandem mass spectrometric determination of hydrolysis products of nerve agents alkyl methylphosphonic acids by p-bromophenacyl derivatization

For proof of the presence of chemical warfare agents sarin, soman and VX, a rapid, accurate and sensitive method which allows us to determine their hydrolysis products ethyl methylphosphonic acid, isopropyl methylphosphonic acid and pinacolyl methyl phosphonic acid was explored by using continuous flow frit fast atom bombardment (FAB) LC-MS and LC-MS-MS. After derivatization of analytes with p-bromophenacyl bromide, LC-MS-MS analyses for screening were performed by a flow injection method. The three alkyl methylphosphonic acids (AMPAs) were eluted within 5 min, and the detection limits for the three AMPAs ranged from 1 to 5 ng/ml. For confirmation of the screening results, LC-MS-MS analysis with chromatographic separation was conducted by using a narrow bore column. The three AMPAs were all eluted with excellent separation within 25 min, and the detection limits ranged from 1 to 20 ng/ml. Quantitative measurement was performed by LC-MS in selected ion monitoring (SIM) mode with chromatographic separation. Linear calibration curves were obtained for the three AMPAs and the detection limits ranged from 0.5 to 3 ng/ml. The relative standard deviation for peak area ranged from 3.4 to 6.0% at 50 ng/ml for the three AMPAs.

Determination of bromvalerylurea and its metabolites in biological samples by frit-fast atom bombardment liquid chromatography-mass spectrometry

A simple, rapid, and sensitive method which allows us to simultaneously determine bromvalerylurea (BVU) and its three metabolites (3-methylbutyrylurea [MVU], alpha-(cystein-S-yl)isovalerylurea [CVU], and alpha-(N-acetylcystein-S-yl)isovalerylurea [AcCVU]) was investigated by frit-fast atom bombardment liquid chromatography-mass spectrometry (frit-FAB LC-MS). The LC-MS analysis was performed after the solid-phase extraction from tissue and urine samples with a Sep-Pak C18 cartridge. Tissue homogenates and urine were adjusted to pH 4.0 and applied to the cartridges. The retained BVU and its metabolites were eluted from the cartridge with 2 mL of acetonitrile/10 mM ammonium acetate buffer (pH 3.5, 50:50, v/v). The eluate was analyzed by LC-MS, which employs a semimicro type L-column ODS column. The proposed conditions are as follows: mobile phase A, 0.4% glycerol in acetonitrile/10 mM ammonium acetate buffer (pH 3.5) (5:95, v/v); mobile phase B, 0.4% glycerol in acetonitrile; elution mode, linear gradient, 100% A (5 min) to 100% B in 15 min; flow rate, 0.2 mL/min; split ratio, 1:40. Extraction recoveries of BVU and its metabolites were 91.90-97.79% from the spiked liver homogenate and 89.68-96.13% from the spiked urine. The detection limits ranged from 10 to 25 ng/g in selected ion monitoring mode.

Mushroom worker's lung resulting from indoor cultivation of Pleurotus osteatus

Indoor cultivation of oyster mushroom Pleurotus osteatus lead to an outbreak of extrinsic allergic alveolitis in two workers. High titer of indirect fluorescent antibody and positive precipitins against basidiospores of P. osteatus were demonstrated in sera of the patients. Mushroom workers should protect themselves from the basidiospores, being aware of their pathogenicity.

Identification of metabolites of nerve agent VX in serum collected from a victim

A human serum sample collected from a victim of the Osaka VX incident was analyzed according to our developed technique for metabolites of VX. Gas chromatography-mass spectrometry (GC-MS) in full-scan electron impact and chemical ionization modes were used, and, for more reliable confirmation, GC-MS-MS was also employed. In the serum sample, both ethyl methylphosphonic acid and 2-(diisopropylamino-ethyl)methyl sulfide were detected. These results indicated that the techniques using GC-MS and GC-MS-MS were applicable to biological samples such as serum. These results also provide the first documented, unequivocal identification of the specific metabolites of VX in victim's serum and, furthermore, clarify a part of the metabolic pathway of VX in the human body.

Detection of designer drugs in human hair by ion mobility spectrometry (IMS)

Since its inception in the early 1970s under the name plasma chromatography, ion mobility spectrometry (IMS) has undergone great changes. It is now utilized more and more in forensic science laboratories where it is used to detect explosives and environmental pollutants [1-4] as well as its use in detecting drugs of abuse [5-8]. Although IMS is known for nearly 30 years now [9], relatively few cases of the application of ion mobility spectrometry to the analysis of human hair have been reported [10-12]. The authors report a new and quick method to rapidly screen and determine MDMA ('ecstasy', 'Adam') and MDEA ('Eve') in human hair. The proposed method using trihexylamine as internal standard resulted in a rapid procedure useful in screening human hair specimens for designer drugs.

GC and GC-MS determination of fluoroacetic acid and phenoxy acid herbicides via triphasal extractive pentafluorobenzylation using a polymer-bound phase-transfer catalyst

A simple and sensitive gas chromatography and gas chromatography-mass spectrometry (GC-MS) procedure has been developed for fluoroacetic acid (FA) and phenoxy acid herbicides (PAHs) via triphasal extractive pentafluorobenzylation. The triphasal system consisted of an aqueous sample, the extraction solvent toluene containing pentafluorobenzyl bromide as the derivatization reagent, and polymer-bound tri-n-butyl-methylphosphonium bromide as a phase-transfer catalyst, FA spiked in beverages, such as orange juice and milk, was extracted as its pentafluorobenzyl (PFB) derivative under moderate conditions (i.e., at a pH value of 6.5 at 60 degrees C). The detection limits were 0.10-0.20 microgram/mL by GC with electron-capture detection (GC-ECD), and 0.42-0.50 microgram/mL by full-scan GC-MS. PAHs were also detectable in the same manner within the detection limits of 0.05-0.10 microgram/mL by GC-ECD and 0.13-0.25 microgram/mL by full-scan GC-MS. Urine and serum which both contained 2,4-dichlorophenoxyacetic acid could also be analyzed by GC-MS after the triphasal pentafluorobenzylation. The detection limit was 0.20 microgram/mL in the full-scan mode and 10 ng/mL in the selected ion monitoring mode both for the urine and serum.

[A case of pleuritis caused by strongyloides in a carrier of T-cell lymphoma virus type I (HTLV-I)]

A 73-year-old woman was admitted to our hospital complaining of dyspnea, fever and general edema. Chest roentgenogram showed bilateral pleural effusion and cardiomegaly. Cardiovascular examination demonstrated atrial tachycardia and left ventricle dysfunction, suggesting congestive heart failure. She was sero-positive for human T-cell lymphoma virus I (HTLV-I). The dyspnea and general edema improved after therapy for heart failure. Because the pleural effusion persisted after therapy, thoracentesis was performed. The pleural effusion was an exudate, and Strongyloides sterocoralis was detected by microscopy. Two courses of thiabendazole (1,500 mg/day, 3 days) were given orally. After this therapy, the pleural effusion improved markedly. This case suggests that Strongyloides stercoralis may be a causative agent of pleuritis in HTLV-I endemic areas.

[An autopsy case of carbon dioxide intoxication]

A 44-year-old male, engaged in the transportation of dry ice, was found dead on the floor of the freezer of his refrigerator car which was parked in front of the place where he was scheduled to make a delivery. Autopsy was performed to investigate the cause of death. Apart from the signs of acute death, no other significant findings were obtained, either macro or microscopically; carbon dioxide poisoning was thus strongly suspected. We created a simulation experiment by using the refrigerator car to reproduce the events of the accident. The oxygen concentration in the freezer was 21.0% as indicated by oxygen sensors, but decreased to 17.1-17.4% when the engine was stopped. This decrease in oxygen concentration supposedly results from the production of carbon dioxide by the vaporization of dry ice. Carbon dioxide concentration in the air could be calculated from the change in the oxygen concentration in the closed space of the freezer. The concentration was assessed at 17.1-18.6%. An oxygen concentration of 17.1-17.4% does not of itself cause serious hypoxia, but a carbon dioxide concentration of 17.1-18.6% probably causes serious intoxication, because this value is beyond that of intoxication levels published in references. Therefore, we concluded that the cause of death in this case was carbon dioxide intoxication.

Determination of the main hydrolysis products of organophosphorus nerve agents, methylphosphonic acids, in human serum by indirect photometric detection ion chromatography

For the verification of the use of chemical warfare agents (CWA), sarin, soman and VX, a simple rapid and accurate method which allows us to simultaneously determine their degradation products, isopropyl methylphosphonic acid (IPMPA), pinacolyl methylphosphonic acid (PMPA), ethyl methylphosphonic acid (EMPA) and methylphosphonic acid (MPA), in human serum, was explored by indirect photometric detection ion chromatography (IPD-IC) which employs an anion-exchange column. IC analysis was performed after sample preparation with an Ag+-form cation-exchange resin cartridge, and the four methylphosphonic acids could be separated well. The proposed conditions are as follows: eluent, 0.5 mM phthalic acid-0.1 mM Tris (hydroxymethyl) aminomethane-5% acetonitrile; flow-rate, 1.0 ml/min; temperature, 50 degrees C; UV detector, 266 nm. All four methylphosphonic acids were eluted within 30 min with hardly any disturbance by impurities in the serum. Linear calibration curves were obtained for MPA, EMPA and IPMPA in the concentration range from 50 ng/ml to 1 microg/ml and for PMPA from 100 ng/ml to 1 microg/ml. The relative standard deviation for the methylphosphonic acids ranged from 3.8 to 6.9% at 500 ng/ml and the detection limits were 40 ng/ml for MPA, EMPA and IPMPA and 80 ng/ml for PMPA. The method would be suitable for analysis of human serum samples.

Application of ion mobility spectrometry to the rapid screening of methamphetamine incorporated in hair

Using ion mobility spectrometry (IMS), a simple, sensitive and rapid screening for methamphetamine (MA) incorporated in user's hair has been developed. To completely unbind MA from hair matrix and to achieve its effective vaporization for the IMS detection, the hair sample was digested in 5 M NaOH (methanol-water, 4:1, v/v) solution prior to IMS measurement. MA in hair was semi-quantitatively detected by monitoring the digested hair sample employing dibenzylamine (DBA) as internal standard. The minimum amount of hair sample required was 2 mg and its digested sample was ample for four IMS measurements. The detection limit of MA in hair was 0.5 ng mg(-1). This proposed method was applicable to the semi-quantitative detection of MA in users' hair samples, and to the sectional analysis for MA in a limited amount of user's hair. The IMS results obtained were in good agreement with their GC-MS determination.

Determination of the main hydrolysis product of O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate, ethyl methylphosphonic acid, in human serum

For the unequivocal proof of the use of a nerve agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX), a rapid, accurate and sensitive method which allows us to identify its main hydrolysis product ethyl methylphosphonic acid (EMPA) in human serum was explored by GC-MS. GC-MS analysis was performed after solvent extraction with acetonitrile in acidic conditions from the serum sample, which was previously deproteinized by micro-ultrafiltration, and subsequent tert.-butyldimethylsilyl derivatization with N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) with 1% tert.-butyldimethylsilyl chloride (t-BDMSC). Linear calibration curves were obtained in the concentration range from 50 to 500 ng/ml for EMPA in the full-scan EI mode and from 5 to 50 ng/ml for EMPA in the SIM EI mode. The relative standard deviation obtained at a sample concentration of 50 ng/ml was 8.4% in the full-scan mode and 7.3% in the SIM mode. Upon applying the full-scan EI and CI mode, 40 ng/ml and 80 ng/ml were the detection limits. Using the SIM-EI mode, in which the ion at m/z 153 was chosen, the limit was 3 ng/ml.

Simultaneous determination of illicit drugs in human urine by liquid chromatography-mass spectrometry

The method for simultaneous determination and confirmation of illicit drugs (e.g., methamphetamine, amphetamine, ephedrine, methylephedrine, morphine, morphine-3-glucuronide, morphine-6-glucuronide, 6-acetylmorphine, cocaine, and benzoylecgonine) in human urine by thermospray liquid chromatography-mass spectrometry (LC-MS) was studied. The LC-MS separation was performed on a reversed phase column (L-column ODS; 150 mm x 4.6-mm i.d.) using a gradient mobile phase system of 100mM ammonium acetate for 1 min then linear ramps to 100mM ammonium acetate including 40% acetonitrile at 20 min. Extraction was conducted by solid-phase extraction using a Sep-pak C18 cartridge. The drugs were eluted with 2 mliters of 40% acetonitrile in 100 mM ammonium acetate, pH3 (adjusted with acetic acid), from the cartridge. A 50-microL volume of the eluate was injected into the LC-MS. The recoveries by this extraction were 88 to 99%. The mass spectra of methamphetamine, amphetamine, ephedrine, methylephedrine, morphine, 6-acetylmorphine, cocaine, and benzoylecgonine showed the quasi-molecular [M + H]+ ion as the base peak, whereas morphine-3-glucuronide and morphine-6-glucuronide showed [MH-glucuronide]+ ion as the base peak. The calibration graphs were linear and reproducible. Detection limits of these drugs ranged from 2 to 40 ng/mliters by selected ion monitoring (SIM) mode and from 50 to 400 ng/mliters by scan mode. The coefficients of variation for the analysis of these drugs ranged from 4.5 to 9.5% at a concentration of 0.4 micrograms/mliters (n = 10).

[Study of components in crude drugs by headspace gas chromatography. II. Components of atractylodes]

Determination of volatile components in essential oils from Atractylodis plants was studied by headspace gas chromatography. The crude drug of 0.20 g with 1.0 ml of water in a capped vial was heated at 130 degrees C for 45 min. Then 0.5 ml of vaporized components were collected by gas tightsillinge, and were applied into the injection port of GC or GC/MS. Consequently we could analyze and confirm the following components; hinesol and beta-eudesmol were found to be contained in Atractylodis Lanceae Rhizoma and atractylon in Atractylodis Rhizoma. beta-Eudesmol was analyzed by headspace gas chromatography, and the obtained calibration curve showed good linearity over the range from 2.5 micrograms to 10.0 mg. The result agreed with those obtained using numerical analyses by the steam distillation method. Atractylodis was found to have a wide variety of components depending on the available sources and on the stored conditions. This method was, therefore, more rapid and simpler determination of essential oils in crude drugs using headspace gas chromatography than those used previously. The method was useful means of the analyses of components in crude drugs such as Atractylodis plants and quality control.

Application of high-performance liquid chromatography/mass spectrometry to drug screening

High-performance liquid chromatography/mass spectrometry enabled us not only to measure bromvalerylurea rapidly, < or = 2 h following accumulation of human bone marrow, but also to improve sensitivity without interference. The method can be widely and effectively used in the fields of pharmacy and forensic sciences.

Direct high-performance liquid chromatographic and high-performance liquid chromatographic-thermospray-mass spectrometric determination of enantiomers of methamphetamine and its main metabolites amphetamine and p-hydroxymethamphetamine in human urine

For the identification of drug abuse, a simple and rapid method which allows us to distinguish enantiomers of methamphetamine (MA) and its metabolites amphetamine (AP) and p-hydroxymethamphetamine (p-OHMA) in human urine was explored by coupling direct HPLC and HPLC-thermospray-mass spectrometry (HPLC-TSP-MS) both of which employ a beta-cyclodextrin phenylcarbamate-bonded silica column. HPLC analysis was performed after the solid-phase extraction from the urine sample with Bond Elut SCX, and D- and L-enantiomers of MA, AP and p-OHMA could be separated well. The proposed conditions are as follows: eluent, acetonitrile-methanol-50 mM potassium phosphate buffer (pH 6.0) (10:30:60, v/v) flow-rate, 1.0 ml/min temperature, 25 degrees C. The linear calibration curves were obtained for D- and L- MA and AP in the concentration range from 0.2 to 20 micrograms/ml; the relative standard deviation for D- and L-AP and D- and, L-MA ranged from 1.67 to 2.35% at 2 micrograms/ml and the detection limits were 50 ng/ml for D- and L-AP and D-MA and 100 ng/ml for L-MA. For the verification of the direct HPLC identification, HPLC-TSP-MS was also carried out under the same conditions except that acetonitrile-methanol-100 mM ammonium acetate (pH 6.0) (10:30:60, v/v) was used as an eluent. Upon applying the scan mode, 10 ng/ml for D- and L-AP and D-MA and 20 ng/ml for L-MA were the detection limits. Using the selected ion monitoring mode, 0.5 ng/ml, 0.8 ng/ml and 1 ng/ml could be detected for D- and L-AP, D-MA and L-MA, respectively.

Interaction among vitamin C, vitamin E, and beta-carotene

The effects of vitamin C (ascorbic acid), vitamin E (alpha-tocopherol), and beta-carotene as antioxidants and their cooperative action against the oxidation of lipid in solution, membranes, and lipoproteins have been studied and reviewed. Ascorbic acid and alpha-tocopherol act as potent, and probably the most important, hydrophilic and lipophilic antioxidants, respectively. They function at their own site individually and furthermore act synergistically. beta-Carotene has lower reactivity toward radicals than does alpha-tocopherol and acts as a weak antioxidant in solution. It is more lipophilic than alpha-tocopherol and is assumed to be present at the interior of membranes or lipoproteins, which enables it to scavenge radicals within the lipophilic compartment more efficiently than does alpha-tocopherol. The cooperative interaction between vitamin C and vitamin E may be quite probable, that of vitamin C and beta-carotene is improbable, whereas that between vitamin E and beta-carotene may be possible.

Action of beta-carotene as an antioxidant against lipid peroxidation

The action and activity of beta-carotene as a radical-scavenging antioxidant against lipid peroxidation have been studied. beta-Carotene suppressed the free-radical-mediated oxidations of methyl linoleate in benzene solution and soybean phosphatidylcholine liposomal membranes in aqueous dispersions in a dose-dependent manner, but the antioxidant activity of beta-carotene was much smaller than that of alpha-tocopherol. beta-Carotene was 32 times less reactive toward peroxyl radical than alpha-tocopherol and approximately as reactive as 2,6-di-tert-butyl-4-methylphenol in benzene solution. Toward carbon-centered radical, beta-carotene was 11 times less reactive than alpha-tocopherol. When beta-carotene and alpha-tocopherol were present together in homogeneous solution, alpha-tocopherol was consumed predominantly and beta-carotene was spared. When they were incorporated simultaneously into the same dimyristoyl phosphatidylcholine liposomal membranes and the radicals were formed in the aqueous phase, alpha-tocopherol was consumed faster than beta-carotene, but the sparing efficacy was much smaller than in homogeneous solution. On the contrary, beta-carotene was consumed faster than alpha-tocopherol when the radicals were generated within the lipophilic compartment of the membranes, implying that beta-carotene is relatively more favorable than alpha-tocopherol for scavenging lipophilic radicals within the membranes. In contrast to an efficient synergistic inhibition by a combination of alpha-tocopherol and ascorbic acid, cooperative interaction between beta-carotene and ascorbic acid was not observed. beta-Carotene underwent autooxidation to give polymeric products and the rate of consumption of beta-carotene increased with increasing concentrations of itself and oxygen and decreased with increasing concentration of lipids. The formation of polymeric products was confirmed by gel permeation chromatography. It was concluded that beta-carotene is less potent as an antioxidant than alpha-tocopherol because beta-carotene is less reactive toward peroxyl radical than alpha-tocopherol and the stable beta-carotene radical reacts with oxygen to give beta-carotene peroxyl radical which is not stable but able to attack lipid to continue chain oxidation. The higher antioxidant activity of beta-carotene at lower oxygen pressure is attributed primarily to an unfavorable formation of beta-carotene peroxyl radical at higher oxygen pressure rather than a higher reactivity of beta-carotene toward carbon-centered radical than peroxyl radical.

Alpha-1 and beta-adrenergic receptor blocking potencies of bopindolol and its two metabolites (18-502 and 20-785) as assessed by radioligand binding assay methods

1. The pKi value of bopindolol for alpha 1High-subtypes in canine aorta, rat hearts and rat brain was 5.71, 5.52 and 6.56, respectively. In addition, the pKi values of these drugs in canine aorta, rat hearts and rat brain for the alpha 1Low-subtype was very low. 2. The phenylephrine induced-contractions of aortae of guinea pigs and rats were not inhibited by these agents. 3. Both bovine hearts and tracheal smooth muscles indicated that 18-502 had the highest pKi value to beta 1- and beta 2-adrenoceptor subtypes and the rank order of these beta-blocking potencies were 18-502 > bopindolol > 20-785.

The analysis of cocaine and its metabolites by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS)

The method for simultaneous determination of cocaine and its four metabolites (benzoylecgonine, ecgonine methyl ester, ecgonine and norcocaine) in urine by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS) was studied. The mass spectra showed the quasi-molecular ions, [M+H]+ as the base peak. LC/APCI-MS analysis was performed by focusing the characteristic ions at m/ = 186, 290, 200, 304 and 290 for ecgonine, benzoylecgonine, ecgonine methyl ester, cocaine and norcocaine, respectively. Cocaine and its four metabolites were well separated by high performance liquid chromatography (HPLC). The recoveries of cocaine and its metabolites from the spiked urine were 40.3-94.7% by solid-phase extraction with two type cartridges (Bond Elut Certify and Bond Elut SCX).

Alterations of binding characteristics of alpha 1-,beta 1-adrenoceptors and Ca2+ binding sites in the myocardium of spontaneously hypertensive rats (SHR) by chronically administered bunazosin, atenolol, ketanserin and verapamil

The effects of chronic treatment with bunazosin, atenolol, ketanserin and verapamil on the myocardium of the spontaneously hypertensive rat (SHR) were examined by the radioligand binding assay method using [3H]prazosin, [125I]iodocyanopindolol and [3H]nitrendipine binding to alpha 1- and beta 1-adrenergic receptors and Ca2+ binding sites. The norepinephrine concentration in the rat myocardium was also determined. (1) All of these drugs lowered the elevated blood pressure of the SHR. (2) Only ketanserin administration increased the Kd value of the alpha 1-adrenoceptor in the SHR. (3) Administration of atenolol and ketanserin to the SHR decreased the Bmax value of the beta 1-adrenoceptor. (4) Verapamil, bunazosin and atenolol also lowered the Bmax values of the Ca2+ binding sites of SHRs. (5) All drugs except for atenolol lowered the norepinephrine concentration in the myocardium of the SHR. These findings suggest that the SHR has an abnormality of the alpha 1- and beta 1-adrenoceptors and Ca2+ binding site of the myocardium, that the drugs had a beneficial effect on these receptors, that the drugs could also lower the high norepinephrine content in the myocardium of the SHR and that some of these drugs also affected the binding characteristics of other types of membrane receptors.

Nipradilol displays a unique pharmacological profile of affinities for the different alpha 1-adrenoceptor subtypes

The selectivity of antagonistic effects of nipradilol, its four isomers and denitronipradilol, a major metabolite of nipradilol, on alpha 1-adrenoceptor subtypes in rat heart, brain and spleen were examined by radioligand binding assay with [3H]-prazosin. Pharmacological characteristics of these compounds were determined in isolated aortae from rats and guinea pigs. The order of the pKi values for alpha 1High-affinity sites in the heart, spleen and brain was SR > nipradiolol > or = RR > or = SS-RS >> denitronipradilol, but the order of the pKi values for the alpha 1Low-affinity sites was different in the heart and brain. There were good correlations between the pKi values of these compounds for the alpha 1High-affinity sites and the pA2 values for the contractile inhibition of the phenylephrine-induced response in rat aorta. There was no correlation between the pKi values of these compounds for the alpha 1Low-affinity sites and the pA2 values. These results indicate that: 1) alpha 1High-Affinity sites are related to vasoconstriction mediated by alpha 1-adrenoceptors; 2) Nipradilol and its isomers possess low affinity to alpha 1-adrenoceptors; and 3) The nitroxy group in nipradilol is important for its alpha 1-blocking activity.

The affinity of betaxolol, a beta 1-adrenoceptor-selective blocking agent, for beta-adrenoceptors in the bovine trachea and heart

1. The specificity of betaxolol, a beta-adrenoceptor antagonist, for beta 1- and beta 2-adrenoceptors was compared with that of other beta-antagonists, atenolol, ICI-118551, butoxamine and (+/-)-propranolol, in the bovine trachea and heart by competitive interaction with [3H]-CGP12177 as a radioligand. 2. The radioligand Kd values were 0.75 +/- 0.12 and 1.60 +/- 0.11 nM in the trachea and heart, respectively, and the Bmax values were 34.00 +/- 4.41 and 21.54 +/- 2.94 fmol mg-1 protein, respectively. 3. Using ICI-118551, we determined the ratio of beta 1:beta 2-adrenoceptors in the trachea and heart to be approximately 29:71 and 56:44, respectively. 4. In the trachea, a beta 2-predominant tissue, betaxolol and atenolol were more selective for beta 1-adrenoceptor binding sites than beta 2-adrenoceptor binding sites, whereas ICI-118551 and butoxamine were more selective for beta 2-adrenoceptor binding sites. 5. The beta 1-selectivity of betaxolol was 2.2 and 2.7 fold higher than that of atenolol in the bovine trachea and heart. These findings suggest that betaxolol may be useful in the treatment of hypertension, cardiac arrhythmia and angina pectoris.

Assessment of Ca(2+)-antagonistic effect of SM-6586 and its isomers, novel 1,4-dihydropyridine derivatives, by radioligand binding assay

The Ca(2+)-antagonistic effects of the 1,4-dihydropyridine derivative (+/-)SM-6586 and its optical isomers were compared with those of its two derivatives ((+/-)SM-7297 and (+/-)SM-7548) and other Ca(2+)-antagonists using a radioligand binding assay. The Ca(2+)-antagonistic effects of the optical isomers of SM-6586 were in the order of (+) greater than (+/-) greater than (-)SM-6586 in both rat brain and heart. The pKi value of (+)SM-6586 was comparable to those of nimodipine, nicardipine, nifedipine and nitrendipine. The pA2 value for (+)SM-6586 was the highest among the SM-6586 isomers, thus suggesting that (+)SM-6586 has a potent Ca(2+)-antagonistic effect.

The analysis of quaternary ammonium compounds in human urine by direct inlet electron impact ionization mass spectrometry

An accurate and rapid screening test for nine quaternary ammonium compounds (suxamethonium chloride, pancuronium bromide, ambenonium chloride, benzethonium chloride, distigmine bromide, methylbenactyzium bromide, neostigmine bromide, propantheline bromide and pyridostigmine bromide) by direct inlet electron impact ionization mass spectrometry (DI/EI-MS) was investigated. Each compound was extracted from urine as an ion pair with KI3 into dichloromethane. The reliability of the identification of these compounds was verified by the mass chromatographic analysis of their characteristic fragment ions. The analysis of these drugs by DI/EI-MS could be performed within 5 min. The detection limits were between 20-150 ng/ml for the nine compounds. This method appears to be efficient, rapid and suitable as a screening procedure for the quaternary ammonium compounds found in urine.

Comparison of alpha 1-adrenoceptors between rat brain and spleen

Scatchard analyses of 3H-prazosin binding in rat brain membranes showed biphasic curves, which identified the presence of alpha 1High- and alpha 1Low-affinity sites. The alpha 1High-affinity site was completely inhibited by 0.1 microM phenoxybenzamine. On the other hand, 3H-prazosin binding in rat spleen membranes resulted in linear curves that were identical to the binding curve for the alpha 1High-affinity site in the brain. The displacement potencies of alpha 1-adrenergic antagonists were characterized by 3H-prazosin binding to alpha 1High-affinity sites in the rat spleen and brain and alpha 1Low-affinity sites in the brain in the presence of 0.1 microM of phenoxybenzamine. The affinities of WB-4101, phenoxybenzamine, phentolamine, chlorpromazine, labetalol and nifedipine for brain alpha 1High-affinity sites were significantly higher than those in the spleen. The affinities of most ligands for alpha 1Low-affinity sites were significantly lower than those for both alpha 1High-affinity sites in the brain and spleen, but chlorethylclonidine was significantly selective for alpha 1Low-affinity sites, and bunazosin, dibenamine and 5HT had the same affinities for the alpha 1Low- and both alpha 1High-affinity sites. These results show that two alpha 1-adrenoceptor subtypes, alpha 1High- and alpha 1Low-affinity, are present in the rat brain and that a different alpha 1High-subtype, exists in the rat spleen.

Binding characteristics of [3H]ketanserin for serotonin-2 receptor in the rabbit platelet

The present study was designed to examine 1) the properties of [3H]ketanserin binding to serotonin-2 (5HT2)-serotonergic receptors in the rabbit platelet membranes, 2) displacement affinities of various chemicals and 3) difference of the affinities between their chemicals and new agents, MCI-9042 and M-1. The plots of specific binding obtained from the Scatchard analysis using [3H]ketanserin for the platelet membranes were monophasic when the non-specific binding was determined by the use of 0.1 mM serotonin (5HT), and the Kd and Bmax values were 3.93 +/- 0.41 nM and 1.19 +/- 0.20 pmol/mg protein, respectively. The displacement potencies of chemicals which were serotonin receptor-, dopamine receptor-, histamine receptor-, and alpha-adrenoceptor-related agents were characterized by [3H]ketanserin binding to 5HT2-serotonergic receptor. The pKi values of a new antiplatelet agent, MCI-9042, and its metabolite, M-1, were 7.19 and 7.59, respectively and these values were lower than those of ketanserin and pirenperone but higher than those of methysergide, cinanserin and cyproheptadine. The affinities of ketanserin for 5HT2-receptors in the rabbit platelet were similar to those for 5HT2-receptors previously identified in the rat frontal lobe and in canine aorta, but cinancerin was selective to 5HT2-receptors in the rat frontal lobe and in canine aorta, prazosin was selective to 5HT2-receptor in the rabbit platelet, and MCI-9042 and M-1 had the same affinities to the receptors in the rat frontal lobe and in the rabbit platelet.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding characteristics of alpha 1-adrenoceptors in bovine prostate using a radioligand binding assay

Binding characteristics of alpha 1-adrenoceptors in the bovine prostate were examined using a radioligand binding assay. [3H]Bunazosin was used as a radioligand. The optimal incubation conditions for the radioligand binding assay were determined: incubation time (30 min), protein concentration (0.2 mg/tube) and temperature (30 degrees C). Scatchard plots for alpha 1-adrenoceptors in bovine prostates were linear and the Kd and Bmax values were 0.61 nM and 49.8 fmol/mg protein, respectively. The pKi value of terazosin was significantly higher than those of prazosin, bunazosin or phentolamine in the bovine prostate. Since this radioligand binding assay using [3H]bunazosin demonstrated the presence of alpha 1-adrenoceptors in bovine prostates, this method is useful for the assessment of alpha 1-blockers of new chemicals synthesized for the treatment of the benign prostatic hyperplasia.

Beta-blocking potency and selectivity of bopindolol and its two metabolites for beta 1- and beta 2-adrenergic receptors as assessed by radioligand binding assay

Using a radioligand binding assay, we assessed the affinity and selectivity of the antagonistic effects of bopindolol (4-(benzoyloxy-3-tert-butylaminopropyl)-2-methylindole hydrogen-malonate) and its two metabolites, (18-502, (4-(3-tert-butylamino-2-hydroxypropoxy)-2-methyl indole) and 20-785, (4-(3-tert-butylaminopropoxy)-2-carboxyl indole], for beta 1- and beta 2-adrenoceptors and on 5HT1B-receptors in rat brain and heart. In addition, we also determined the pA2 values of these agents for their antagonistic effects toward positive chronotropic and inotropic actions (beta 1-adrenoceptors) and for their antagonistic effects toward isolated tracheal relaxation (beta 2-adrenoceptors), using isoproterenol as an agonist. The data showed that bopindolol was more selective for beta 2-adrenoceptors than for beta 1-adrenoceptors and 5HT1B-receptors, but its two metabolites (18-502 and 20-785) did not have significant selectivity for beta 1- and beta 2-adrenoceptors, using both [3H]CGP12177 and [125I]ICYP ([125I]iodocyanopindolol) bindings. In contrast, the results from pharmacological assessment for antagonistic potencies, using atria and trachea, showed that bopindolol and its two metabolites did not have significant selectivity on beta 1- and beta 2-adrenoceptors. A major metabolite of bopindolol, 18-502, had higher pKi and pA2 values for beta-adrenoceptors and 5HT1B-receptors than those of bopindolol and 20-785. These results indicate, first, that a radioligand binding assay for the assessment of the selectivity of bopindolol and its two metabolites for beta 1- and beta 2-adrenoceptors is more effective than pharmacological experiments, and that there is a possibility that its two metabolites also contribute to the strong beta-blocking action of bopindolol.