The hemolytic and enzymic investigations of the crude venom from Heterometrus gravimanus scorpion have revealed the presence of both direct and indirect (phospholipase A) hemolysins. The direct hemolysins were isolated from the lyophilized crude venom extract by Sephadex G-100 gel filtration, SP-Sephadex C-25 column chromatography, gel filtration of Sepharose 4B and Sephacryl S-300. The two direct hemolysins having high molecular weights, P (A) (M.W. : nearly 200×10⁴) and P (B) (M.W. : 22×10⁴), were obtained with the activity recoveries of 8% and 39.4%, respectively. P (B) was further separated into three fractions by Sephadex G-200 gel filtration, namely F (A) (M.W. : 17×10⁴), F (B) (M.W. : 4.5×10⁴) and F (C) (M.W. : below 1×10⁴), with the significant losses of direct hemolytic activities. However, F (B) had phospholipase A activity and this activity was partially inhibited by p-bromophenacyl bromide. F (B) and F (C) were soluble, even after the treatment of dialysis and lyophilization, in the isotonic saline and distilled water, and were homogeneous in polyacrylamide gels after going through disc and vertical plate electrophoreses. Furthermore, the schlieren pattern of F (B) also showed homogeneity of the preparation. The protein parts of hemolysins were found to be acidic ones. Although ultraviolet spectra of them were somewhat varied in accordance with their protein contents in the samples, the spectra of exitation and emission were almost identical. The direct hemolysins are presumably glycoproteins, since they are positive in the sugar reactions, and the difference between P (A) and P (B) is supposed to consist in the sugar part rather than that of proteins.

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It was shown that the human erythrocyte ghost membrane had two kinds of binding site for 1-anilino-8-naphthalene sulfonate (ANS) from binding kinetics. In measuring the fluorescence lifetime of ANS in the human erythrocyte ghost membrane suspension, two kinds of fluorescence lifetime were obtained : τ₁=15 ns at low ANS concentration and τ₂=8.4 ns at high ANS concentration. Comparing the results obtained from binding kinetics with those from fluorescence lifetime, it was considered that more hydrophobic binding site with fluorescence lifetime τ₁ contained the binding site with high and low binding constant and less hydrophobic binding site with fluorescence lifetime T₂ corresponded to the binding site with low binding constant. From the results of binding kinetics of ANS to the erythrocyte membrane and the extracted membrane components (proteins and lipids), and those of the rotational relaxation time obtained from the ANS polarization in the erythrocyte membrane suspension, it was shown that the binding sites of ANS in the human erythrocyte ghost membrane were mainly composed of proteins at low ANS concentrations and lipids at high ANS concentrations.

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cis-Diamminoplatinum (II) complexes with selenoguanine, thioguanine, 6-thioxanthine, or 6-mercaptopurine were synthesized by the reaction of stoichiometric amounts of selenopurine or thiopurine with aquated cis-dichlorodimmineplatinum (II) in slightly acidic medium, and their antitumor activity was studied against L1210 cells in mice. These compounds exhibited a medium antitumor activity with very low toxicity. The antitumor activity was dependent on the nature of the purine ligand. These complexes were very stable in various aqueous solvents at 37°C for 10 d but not in the presence of mouse serum. The mechanism of the action effected by the complex is not clear. However, the slow release of an antitumor active purine from the complex, SeG-Pt (NH₃)₂, was observed.

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Effects of acute and chronic phenobarbital treatment on GABA, glutamate, aspartate, glycine and taurine contents in seven regions of the rat brain have been investigated. Rats treated chronically with phenobarbital maintained the hepatic changes known to follow short term treatment and high phenobarbital levels in the liver, brain and serum. After withdrawal, spontaneous convulsions were first observed when phenobarbital level in the serum fell to about 15 μg/ml. Chronic phenobarbital treatment resulted in the decrease of GABA content in the cerebral cortex, midbrain, hypothalamus, striatum and hippocampus. At 2 d after withdrawal, glutamate and aspartate contents were decreased and taurine content was increased with recovery of GABA content. Acute phenobarbital treatment resulted in the decrease of GABA and glutamate contents and the increase of taurine content. The changes of amino acid contents were different among seven regions of the rat brain, but phenobarbital distributed uniformly after acute and chronic treatment. These results indicate that GABA participates, at least in part, in phenobarbital action and abstinence syndrome may arise from a deficiency of GABA.

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Gas chromatographic procedure for the quantitative determination of methyl propyl sulfone (MPS), 2-hydroxypropyl methyl sulfone (2HPMS) and 3-hydroxypropyl methyl sulfone (3HPMS) in urine was developed. By using this procedure, the urinary excreion of MPS, 2HPMS and 3HPMS after oral dose of thiamine propyl disulfide (TPD) was investigated in healthy adults, in order to assess their ability of drug disposition including metabolism. Among these metabolites, 2HPMS was predominant and the other two were minor. 2HPMS was excreted most in the 24-36 h urine and the time course of excretion of this metabolite was almost the same among these subjects. In 4th day urine, a significant amount of 2HPMS was still excreted. On the contrary, the time course of excretion of MPS varied among subjects and also at different occasions in the same subjects. 3HPMS was excreted most in the 0-12 or 12-24 h urine and more rapidly excreted than 2HPMS. Twofold interindividual differences in the amount of 2HPMS in the 0-48 h urine occurred and intraindividual difference was also observed. Inter- and intraindividual differences in the amount of MPS in 0-48 h urine were much larger than that in 2HPMS. In 3HPMS, these differences were slightly lcss than in 2HPMS. Sex difference in the excretion of MPS and 2HPMS was not observed.

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The urinary excretion of 2-hydroxypropyl methyl sulfone (2HPMS) and methyl propyl sulfone (MPS) after oral administration of thiamine propyl disulfide (TPD) was examined in the patients with various liver diseases, in order to investigate the relationship between the liver function and the ability of drug disposition including metabolism. The patients were divided into six groups as follows ; acute hepatitis in convalescent stage (AHconv), acute hepatitis in active stage (AHact), chronic inactive hepatitis (CIH), chronic active hepatitis (CAH), liver cirrhosis in compensated stage (LCcom) and decompensated stage (LCdec). The results obtained from these groups were compared with those of normal subjects. For MPS, only LCdec showed either lesser or delayed excretion in the 0-48 h urine compared to normal subjects. In other liver diseases the excretion pattern of MPS was similar with that of normal subjects, and the amount excreted in the 0-48 h urine was not significantly different. In urinary excretion of 2HPMS, the amount excreted in the 0-48 h urine decreased in the order CIH > AHconv > AHact > CAH > LCcom > LCdec, and the decrease in the amount correlated roughly to the severity of liver disease. This amount in liver disease, except CIH, was significantly less than that in normal subjects. Differences between CIH and CAH, and LCcom and LCdec were also significant. Delayed excretion of 2HPMS was observed in chronic liver diseases, especially in LCdec. Excretion of 2HPMS in the 0-48 h urine was correlated with the alterations of liver functions such as serum albumin concentration, serum choline esterase activity, hepaplastin test and indocyanine green tolerance test. From the results, measurement of the amount of 2HPMS excreted in the 0-48 h urine after oral dose of TPD is suggested to be useful for evaluation of the liver function.

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The effect of anesthesia induced with pentobarbital and diethyl ether on the drug disposition were investigated in the rat. The disposition rate constants of gentamicin and tobramycin were decreased significantly during the anesthesia with pentobarbital and ether without influence on the volume of distribution. In addition, the decrease in disposition rate constant was correlated significantly with the rectal temperature of the rat. These findings suggest that the decreased disposition rate constant will be responsible for decrease in renal blood flow correlating with the rectal temperature. But, the effect of anesthesia with ether for 30 min persisted for 2 h, even after the rectal temperature recovered to the value for the unanesthetized rats. These facts indicate that factors other than blood flow or rectal temperature might also be considered for the effect of ether anesthesia. Furthermore, the disposition rate constant of sulfanilamide was also decreased under pentobarbital anesthesia, with slight increase in acetylated fraction of sulfanilamide excreted into urine in 24 h. The calculated rate constants of metabolism and excretion were both greatly decreased by the pentobarbital anesthesia. Thus, controlling the anesthetic condition during the experiments will be important to investigate the pharmacokinetics of drugs.

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Effect of food on the bioavailability of griseofulvin from its two plain tablets, a commercial microsize product and a PEG ultramicrosize (GRIS-PEG^R) one, was investigated. The drug was dissolved at a slower rate from ultramicrosize formulation than from microsize one in 18 1 of pH 7.2 buffer but at a little faster rate in 40% dimethylformamide. When administered to fasting subjects, the microsize product showed higher serum levels and peak serum level than ultramicrosize one but the extent of the bioavailability was nearly the same. A standard breakfast enhanced the rate of absorption of the drug from both the products, especially from ultramicrosize one, and those products were equivalent in the rate and extent of bioavailability after food ingestion. The peak serum level of ultramicrosize product in nonfasting was about twice higher than that in fasting subjects. The different intensities of food effect on the bioavailabilities from two dosage forms suggest that formulation factors should be considered for the evaluation of food effect.

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Bence-Jones protein (BJP) was isolated from the urine of a patient with macroglobulinemia by salting out with ammonium sulfate, followed by chromatography on DEAE-cellulose column and gel filtration. This native BJP was identified as k-type light chain by immunoelectrophoresis and the native light chain showed almost no activity of inhibiting the gastric ulceration in pylorus-ligated rats. In contrast, reduction of the disulfide bond by 2-mercaptoethanol and alkylation of the thiol by iodoacetate in this native light chain resulted in significant inhibition of the gastric ulceration. The alkylated light chain also showed a significant inhibition of gastric juice secretion in pylorus-ligated rats.

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Metabolism of styrene, racemic phenyloxirane, (R)-(+)-, and (S)-(-)-phenyloxiranes in rats has been described. The animals excreted phenylethanediol, mandelic acid, phenylglyoxylic acid, and two regioisomeric mercapturic acids in their urine after the intraperitoneal injection of the phenyloxiranes as well as styrene. The mercapturic acids were identified as N-acetyl-S-(1-phenyl-2-hydroxyethyl) cysteine (MA-1) and N-acetyl-S-(2-phenyl-2-hydroxyethyl) cysteine (MA-2). The ratios of the mercapturic acids to the other metabolites excreted in the urine were 1 to 1.8 and 1 to 1.5 for styrene and racemic phenyloxirane, respectively. A remarkable stereoselectivity was observed in the excretion of both types of the metabolites when optically active phenyloxiranes were administered. The rate of excretion of the mercapturic acids was 2.5 times higher than that of the other metabolites when the (R)-oxirane was injected, but the reverse was the case in the (S)-oxirane. The mercapturic acid, MA-1, was excreted at higher rate than the isomer, MA-2, on the administration of styrene and the phenyloxiranes. The most significant regioselectivity in the excretion of MA's was observed when styrene and (S)-phenyloxirane were administered.

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In addition to six metabolites of oxycodone which were reported previously, 7β-hydroxy-6β-oxycodol was further isolated as one of the major metabolites in rabbits. The structure of this novel metabolite was characterized by mass and nuclear magnetic resonance spectra. Such a metabolite possessing vicinal hydroxyl groups in aliphatic ring is very new in the metabolism of narcotic analgesics.

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A simple procedure for the preparation of large quantities of tritium-triglyceridelabeled very low density lipoprotein (VLDL) from rat serum is described. Triton WR-1339 (0.10 ml) was intraperitoneally injected into rats weighing 200-300 g, and 100 μCi of tritium-triolein in corn oil (1 ml) was simultaneously administered orally. VLDL was separated by ultracentrifugation from the serum administration of the above compounds for 2 d. At least 10 mg of protein of VLDL was obtained from each animal, and the radioactivity in VLDL was exclusively found in triglyceride. Isolated radioactive VLDL was injected into normal rats, and the decay of the radioactivity in serum was found to be almost identical with that of triglyceride, but different from that of cholesterol.

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