The order of plasma levels of clioquinol and its conjugates in male rats after intraduodenal administration of 32.7 μmol/kg dose of clioquinol was clioquinol sulfate (C-Sul) > clioquinol glucuronide (C-Glu) > > clioquinol, whereas that in female rats was C-Glu > C-Sul > > clioquinol. Total (urine+bile) recovery was almost the same among male and female rats. The percentage of excretion amounts of C-Sul (urine+bile) to the total excretion amounts for 24 h in male rats after intravenous administration of clioquinol was about twice that in female rats, while the percentage of excretion amounts of C-Glu to the total excretion amounts in male rats was smaller than that in female rats. In intravenous administration of 16.4 μmol/kg dose of C-Glu, C-Sul and clioquinol other than C-Glu were found in bile and urine of male and female rats. The percentage of excretion amounts of C-Sul and C-Glu (urine+bile) to the total excretion amounts was similar among male and female rats, respectively. In intravenous administration of 16.4 μmol/kg dose of C-Sul, C-Glu and clioquinol other than C-Sul were found in bile and urine of male and female rats, and the percentage of excretion amounts of C-Sul (urine+bile) to the total excretion amounts in male rats was 1.3 fold that in female rats. From the examination of the in vitro conjugation reaction, the formation rate of C-Glu in the small intestine was approximately same among male and female rats, whereas C-Glu and C-Sul formation rates in male rats were about twice those in female rats, respectively. From the similarity of the extent of the glucuronidation in the small intestine among male and female rats, one reason for the sex difference in the excretion of the two conjugated metabolites at the intraduodenal administration of clioquinol may be due to the difference in sulfation in the liver.

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Correlation between sensitivity to two cross-linking agents, 1-(4-amino-2-methylpyridine-5-yl)-methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU) and cisplatin (DDP), and intracellular glutathione (GSH) level was investigated for two naturally drug-resistant human colon cancer cell lines in comparison with two drug-sensitive human leukemia cell lines. As a result, no appreciable correlation was observed between them. We also studied the possibility that DL-buthionine-s, R-sulfoximine (BSO), an inhibitor of GSH biosynthesis, can sensitize the cancer cells to these anticancer agents via depletion of intracellular GSH. It was found that BSO potentiated ACNU cytotoxicity against human leukemia K562 cells and DDP cytotoxicity against K562 and human colon cancer WiDr cells. It indicates that cancer cells with higher GSH level are more effectively sensitized by BSO regardless of degree of their intrinsic sensitivity to these anticancer agents. These results suggest that intracellular GSH level is not a common mechanism for natural resistance to cross-linking agents in human colon cancer cells but one of the determinants of sensitivity to these anticancer agents of GSH-rich cells.

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The effects of 2-phenylethylamine (PEA) and related compounds on the spinal monosynaptic reflex (MSR) were examined using Cl-spinalized rats. At low doses, PEA, S (+)-amphetamine, S (+)-methamphetamine and phentermine increased the amplitude of the MSR, whereas high doses of these drugs reduced it. p-Substituted PEA analogs (p-Cl-PEA, p-methoxy-PEA and (±)-p-Cl-amphetamine) only reduced the MSR. Low doses of PEA-related rigid compounds, R (+)-2-aminotetralin, (±)-N-methyl-2-aminotetralin and (±)-N, N-dimethyl-2-aminotetralin only reduced the MSR. S(-)-2-Aminotetralin did not affect the MSR. Depressions of MSR produced by PEA, S(+)-methamphetamine and R (+)-2-aminotetralin were antagonized by ketanserin and haloperidol which have 5-hydroxytryptamine (5-HT) antagonistic activity, and the MSR depression caused by S (+)-methamphetamine but not PEA and R (+)-2-aminotetralin was abolished by intracisternal 5, 6-dihy-droxytryptamine treatment or chronic spinal transection. These results suggest that PEA-related compounds cause MSR depression by direct and indirect 5-HT agonistic mechanisms, and support the proposal that the PEA moiety which exists in R (+)-2-aminotetralin is important for the direct 5-HT agonistic activity of some hallucinogens.

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Disposition of phenacetin (PHT) administered intravenously was investigated in rabbits pretreated orally and intraperitoneally with 3, 4-benzpyrene. 3, 4-Benzpyrene pretreatment intraperitoneally 24 and 48 h before the disposition experiments resulted in enhanced PHT metabolism as was shown from the decreased levels of PHT and the increased levels of acetaminophen sulfate (NAPAS) in the blood after intravenous administration of PHT. Following the oral pretreatment with 3, 4-benzpyrene 24 h before the disposition experiments, no effect was found on the metabolism of PHT compared to the control. 3, 4-Benzpyrene pretreatment orally 48 h before the disposition experiments resulted in enhanced PHT metabolism as was shown from the decreased levels of PHT and the increased levels of acetaminophen glucuronide and NAPAS in the blood. From these results, the response to oral and intraperitoneal pretreatment with 3, 4-benzpyrene appears to be profoundly different. A technique for selective enzyme induction in the intestine by the route of administration of inducer is discussed.

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A set of 16 serotype specific monoclonal antibodies (MoAbs) against Pseudomonas aeruginosa classified by Homma were obtained by the mouse hybridoma technique. This set of MoAbs was useful for classification of their serotypes especially O-antigen groups G and M. MoAb obtained from serotype 15 of Homma's classification reacted with serotype 17 of the same classification. We also obtained two MoAbs which reacted with 7 Homma's serotypes of 6 different O-antigen groups and one MoAb which recognized all 4 Homma's serotypes of O-antigen group B. These MoAbs were also useful in mice for the preventive effect against the infections of P. aeruginosa.

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The effect of a newly developed quinolone, NY-198, on the pharmacokinetics and metabolism of theophylline was investigated under steady-state conditions in six male healthy volunteers, in a crossover fashion. A sustained-release theophylline formulation (200 mg twice daily at 12 h intervals) was received as monotherapy or coadministration with NY-198 (200 mg twice daily at 12 h intervals). No significant change in the pharmacokinetic parameters of theophylline was observed during coadministration of NY-198. No significant change in urinary excretion of theophylline and its metabolites was also observed. These findings indicate that NY-198 does not influence the pharmacokinetics of theophylline and we can suggest that quinoline derivatives have less effect on theophylline disposition than 1, 8-naphthyridine derivatives among quinolones.

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A sensitive enzyme immunoassay for human epidermal growth factor (hEGF) is described. The anti-hEGF antibody was prepared by immunizing rabbits with hEGF, which was synthesized by Escherichia coli using the genetic engineering technique. The present assay system was based on the sandwiching of an antigen between anti-hEGF F (ab')₂ precoated on a 96-well polystyrene plate and β-D-galactosidase-labeled anti-hEGF Fab'. The range of measurable hEGF by this assay was 0.1-100 pg/well. Recoveries of hEGF added to serum and urine ranged between 94 and 108%. The intra-and inter-assay coefficients of variation were less than 6 and 8%, respectively. The results obtained by this assay method correlated well with those obtained by the radioimmunoassay method. By using this assay, the time course of serum hEGF levels in mice after the various administrations were also examined.

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Interaction of fractionated ³H-heparin with plasma proteins was investigated by gel filtration chromatography. The peak of the elution profile for fractionated ³H-heparin in rat plasma was observed at the higher molecular weight fraction than that for fractionated ³H-heparin in buffer without any protein, suggesting the existence of fractionated ³H-heparin binding protein (s) in plasma. Then the interaction of fractionated ³H-heparin with such plasma proteins as albumin, antithrombin III, thrombin and α-globulin was investigated. The elution profile for fractionated ³H-heparin in albumin solution, antithrombin III solution and the solution containing antithrombin III and thrombin were different from that for fractionated ³H-heparin in plasma. The elution profile for fractionated ³H-heparin in α-globulin solution, of a concentration close to that in plasma, was comparable to that of fractionated ³H-heparin in plasma, though two peaks were found. The major peak corresponded to that of fractionated ³H-heparin in plasma, and the minor peak eluted at a higher molecular weight fraction. When α-globulin concentration was decreased, the major peak shifted to the lower molecular weight fraction, and the minor peak was diminished and then disappeared. Thus it was suggested that α-globulin is dominant for plasma protein binding of fractionated ³H-heparin.

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Hydrochlorothiazide (HCT) was administered orally to healthy volunteers and intravenously to rabbits. HCT concentrations in plasma (C_p) and erythrocytes (C_e) were determined by a high-performance liquid chromatographic method. C_e was about 9-fold that of C_p 24 h after the administration to volunteers, and 8-fold 6 h after the administration to rabbits. From the results of the in vitro binding study which was done with rabbits erythrocytes, at least the presence of three kinds of binding site for HCT was expected. The first binding site was characterized by extremely high affinity and very low capacity, and was unaffected by acetazolamide, known as a carbonic anhydrase inhibitor. The second one was characterized by medium affinity and medium capacity, and disappeared under the presence of acetazolamide and may be due to the carbonic anhydrase of erythrocytes. The third one was characterized by low affinity, but its binding capacity was extremely high and apparently unsaturable in the HCT concentration range studies (0.5-100μg/ml=1.68-336μM). The binding of HCT to erythrocytes seems to be dominated by the second binding site in the therapeutic range (under 1 μg/ml of plasma).

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Employing two types of brain ischemic animal models, an attempt was made to evaluate the protective effect of naftidrofuryl as the normalizing effect on the ischemia-induced changes in the brain levels of monoamines and metabolites. 1) During 2 min ligation of both left and right common carotid arteries of mice, dopamine (DA) content alone significantly decreased among three monoamines and four metabolites measured by a high performance liquid chromatography-electrochemical detection method. Pretreatment with naftidrofuryl oxalate (45 mg/kg, i.p.) was found to prevent the DA change, but the lower dose (15 mg/kg, i.p.) of the drug or any other drug tested individually (vinpocetine hydrochloride : 2 mg/kg, Ca hopantenate : 0.1 g/kg, citicoline : 0.1 g/kg, i.p.) had no such effect. 2) Infusion of carbon microsphere (500 particles/100 μl of 20% dextran/1.5 min/rat) into the right internal carotid artery induced various degree of time-dependent changes in the behavior and also in the brain levels of monoamines and metabolites. Embolized rats which otherwise would survive for at least 6 d after infusion, were divided into the lightly-infarcted and severely-infarcted groups by grading the behavioral abnormality. Subsequent treatments with naftidrofuryl oxalate (15 mg/kg, i.p., twice daily, totally 4 times) which was begun 16 h after microsphere injection, was found to accelerate the recovery rate of brain dopamine level once decreased by the embolism though only in the lightly-infarcted group. The significance of the results obtained herein were discussed in relation to the clinical effectiveness of naftidrofuryl in human brain ischemic diseases.

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We investigated the effects of psychotropic drugs on reflex tracheal constriction in anesthetized, paralyzed, and artificially ventilated mongrel dogs. The tracheal constriction induced by the electrical stimulation of the central cut end of the right vagus nerve was abolished by sectioning both the left superior laryngeal and recurrent laryngeal nerves, and was reduced by a low dose of pentobarbital (3 mg/kg, i.v.). This indicates that the tracheal constriction is mediated by a vagal reflex. Chlorpromazine (3 mg/kg, i.v.) and imipramine (1-3 mg/kg) reduced the reflex tracheal constriction. Chlorpromazine and imipramine had no effect on the tracheal constriction induced by the efferent electrical stimulation of the recurrent laryngeal nerve. This suggests that the higher centers may affect the reflex airway constriction and that the present preparation may be useful for investigating the effect of psychotropic drugs on the reflex airway constriction during asthmatic attacks.

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