Structural determination of a directly mutagenic amino-nitrobiphenyl as the S9 metabolite of 2,4,2',4'-tetranitrobiphenyl in Salmonella typhimurium TA98

In order to elucidate the mechanisms of mutagenic activation of nitrobiphenyls by mammalian activation systems, 2,4,2',4'-tetranitrobiphenyl was incubated with S9 and its mutagenic metabolites were separated by SiO2 and Al2O3 column chromatography. The most mutagenic diamino-dinitrobiphenyl was isolated from the reaction mixture of 2,4,2',4'-tetranitrobiphenyl with S9 mix at 37 degrees C for 48 h, and its mutability was 4646 revertants/50 ng in Salmonella typhimurium TA98 without S9 mix. The deamination product of this most mutagenic metabolite was identical to 2,4'-dinitrobiphenyl by gas chromatography-mass spectrometry. Therefore, the structure of the metabolite was determined as 2,4'-diamino-2',4-dinitrobiphenyl by its chemical and physico-chemical properties.

Prostaglandins antagonize fibroblast proliferation stimulated by tumor necrosis factor

Tumor necrosis factor (TNF) is known to be a mitogen for human diploid FS-4 fibroblasts. We have shown in an earlier study (Hori et al. (1989) J. Cell. Physiol. 141, 275-280) that indomethacin further enhances the cell proliferation stimulated by TNF. Since indomethacin inhibits the activity of cyclooxygenase, the role of prostaglandins in TNF-stimulated cell growth was examined. Cell growth stimulated by TNF and indomethacin was inhibited by exogenously added prostaglandins (PGE2, PGF2 alpha, and PGD2), among which PGE2 caused the greatest inhibition of cell growth. Treatment of FS-4 cells with 10 ng/ml TNF resulted in the release of prostaglandins (PGE2, 6-keto-PGF1 alpha, PGA2, PGD2, and PGF2 alpha) 2 to 4 fold over that of untreated cells. The amount of all these prostaglandins increased in a time-dependent manner over 6 h after treatment. In both TNF-treated and control cells, PGE2 was released as the predominant prostaglandin. Furthermore, when PGE2 production and DNA synthesis were determined in FS-4 cells treated with increasing doses of indomethacin, these two cellular responses were inversely affected by indomethacin. These data show that prostaglandins induced by TNF antagonize growth stimulatory action of TNF.

Isoelectric focusing of isoenzymes of monkey platelet monoamine oxidase

Monkey platelet monoamine oxidase (MAO) was preferentially found as the B-form of the enzyme as observed from differences in substrate specificities, as well as liver MAO. The isoelectric points and molecular weights of platelet MAO subunits were compared with those of monkey liver using sodium dodecyl sulfate-disc polyacrylamide gel electrophoresis and isoelectric focusing-disc gel electrophoresis. The pI value of monkey liver was a single peak at 6.5, but the pI values of monkey platelets were triple peaks at 5.5, 6.5 and 7.0. The molecular weight of MAO subunits in monkey platelets was similar to that of liver, and was found to be about 60,000. These results indicate that MAO-B of monkey platelets differs from MAO-B of the liver, and that it has different electrophoretic properties.

Effects of food intake and meal size on the bioavailability of sulpiride in two dosage forms

This study examined the influences of food intake on sulpiride (100 mg) bioavailability from a commercial film-coated tablet and of the meal size (small, medium or large) on sulpiride bioavailability from an aqueous solution in three healthy male volunteers. The cumulative urinary excretions of sulpiride for 48 h (Du48) from two dosage forms following oral administration were decreased approximately 30% by food intake. Also, a good correlation was found between the bioavailability of sulpiride from the solution and size of meals with the same dietary components. These results suggest that food intake and meal size before dosing significantly affect the gastrointestinal absorption of sulpiride.

Thyroid hormone-inducible monoamine oxidase inhibitor in rat liver cytosol

An endogenous inhibitor of monoamine oxidase (MAO) was separated by gel-filtration from 105,000 g supernate of T4-treated rat liver cytosol. The inhibition by this inhibitor was concentration-dependent and more potent for A-form MAO than for B-form MAO. The mode of inhibition was competitive either with 5-hydroxytryptamine or beta-phenylethylamine. The molecular weight of this inhibitor was estimated to be 600-700 by gel filtration. The pI value was determined to be 3.0 by isoelectric focusing. This inhibitor was proved to be heat-stable and resistant to protease treatment. MAO inhibition activity was much lower in the cytosol of thyroidectomized, non-T4-treated rats than T4-treated rats, suggesting that this inhibitor is induced by thyroid hormone T4. MAO activity in rat liver might be regulated by the level of this inhibitor.

High density recording by superresolution in an optical disk memory system

High density optical disk recording using an optical superresolution technique is proposed. By setting a shading band in the center of the collimating beam, the focused spot size on the recording medium is reduced to 80% compared with that of a conventional optical recording. The readout signal degradation affected by the focused spot sidelobe on the recording medium is suppressed by spatially extracting the main lobe region from the reflected back beam using a slit on a reimaged plane. The linear recording density has been improved to 1.2 times as high as that for a conventional optical recording using a normal resolution optical head.

[Immunohistochemical study on epidermal growth factor and its receptor in human pancreatic carcinoma]

We investigated immunohistochemical expressions of the epidermal growth factor (EGF) and the epidermal growth factor receptor (EGFR) in 25 cases of pancreatic carcinoma, including 13 cases of metastatic lymph nodes. EGF and EGFR were stained mainly in the cytoplasm and on the surface of some pancreatic carcinoma cells, with positive rates of 18/25 (72%) and 9/25 (36%) respectively. In all cases EGFR was noted only when EGF was also detected. EGF and EGFR were stained frequently in differentiated types. In metastatic lymph nodes, EGF and EGFR were found in 54% and 15% respectively, and they were detected only when they were also noted in the same patient's primary lesions. EGF and EGFR were found more frequently in Stages III and IV than in Stage II. These results emphasize that EGF and EGFR may promote both the proliferation and the differentiation of human pancreatic carcinoma cells, as in other sites.

Growth inhibition of human fibroblasts by epidermal growth factor in the presence of arachidonic acid

The effect of epidermal growth factor on growth of human fibroblasts was investigated in serum-free medium supplemented with various fatty acids. When linoleic acid, arachidonic acid, or eicosapentaenoic acid was added, each inhibited epidermal growth factor-induced cell growth and showed cytotoxicity at high concentrations (greater than 10 microM). This cytotoxic effect was not observed in the presence of indomethacin, suggesting that prostaglandin production is important in mediation of the growth inhibition. Prostaglandin E2 was increased more than ten thousand times by epidermal growth factor in combination with arachidonic acid.

Leakage of thyroid hormone-inducible monoamine oxidase inhibitor from rat liver cytosol

T4-induced endogenous monoamine oxidase (MAO) inhibitor in rat liver perfusate by perfusion with sucrose buffer and lipid peroxide (LPO) and superoxide dismutase (SOD) in rat liver tissues were investigated after pretreatment with total hepatic ischemia. When the gel filtration of these rats liver perfusate were carried out using Sephadex G-25, fraction 18-20 were found to inhibit MAO activity. LPO of these rats were increased, but SOD activity was decreased. The accumulation of lipid peroxides would partly result from decreased activity of SOD as a consequence of membrane disorders. These results suggest that T4-induced MAO inhibitor in rat cytosol was released into plasma by membrane disorder.

Hematology in sika deer (Cervus nippon yesoensis Heude, 1884)

Blood samples were taken from 78 wild and 21 farmed sika deer (Cervus nippon yesoensis) using ketamine-xylazine sedation during their excited (82 deer) and resting (17 deer) states. Red cell count (RBC), hemoglobin (Hb), packed cell volume (PCV) and mean corpuscular volume (MCV) were significantly higher and mean corpuscular hemoglobin concentration (MCHC) was lower in excited deer than in resting deer. There was no significant difference in total leukocyte count (WBC) between excited and resting wild males, while a marked increase of WBC with neutrophilia was observed in excited wild females. RBC and PCV were significantly higher and MCH was lower in excited males than in excited females. In wild deer, WBC was significantly higher in females than in males, but there was no significant difference in WBC between farmed males and females. Sex differences in the hematological parameters were not observed in fawns (10 months).

Suppressive effect of bifemelane on lipid peroxidation in rat liver

The effects of Bifemelane (BF) on lipid peroxidation, the activities of hepatic drug metabolizing enzymes, and the function of cell membranes were examined in rats. In the liver ischemia-reperfusion model, BF suppressed the elevation of the lipid peroxidation level during the period of reperfusion. BF did not exhibit a radical-trapping action using a stable free radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), which was estimated by electron spin resonance (ESR). BF remarkably inhibited NADPH-dependent lipid peroxidation in vitro. BF had no effect on the contents of cytochrome P-450 and b5 and the activities of NADPH cytochrome P-450 reductase and Cu,Zn-superoxide dismutase (SOD). BF suppressed phorbol myristate acetate (PMA)-induced superoxide formation of polymorphonuclear leukocytes (PMNs), protected hypotonic hemolysis of erythrocyte and inhibited platelet aggregation induced by adenosine diphosphate (ADP) and serum phospholipase A activity. These results suggest that BF has neither radical-trapping activity nor any influence on the drug metabolizing enzymes, but BF has a membrane-stabilizing action and it attributes to the suppressive effect of lipid peroxidation.

Effect of bifemelane hydrochloride on an injury of the liver caused by ischemia-reperfusion in rats

In the liver ischemia-reperfusion model, the lipid peroxide level increased during ischemic periods, while a greater increase was observed during reflow periods. The increase in the cytochrome b5 content was observed during ischemia and reflow periods. On the contrary, the cytochrome P-450 content remained unchanged during ischemic periods, but decreased during reflow periods. Bifemelane suppressed the elevation of the lipid peroxide level, the cytochrome b5 content and the decrease in cytochrome P-450 content during the period of reperfusion.

Effect of warfarin on plasma and liver vitamin K levels and vitamin K epoxide reductase activity in relation to plasma clotting factor levels in rats

Changes in plasma and liver vitamin K1 and vitamin K1 epoxide levels, liver microsomal vitamin K epoxide reductase activity, and plasma clotting factor II and VII levels were determined in rats after a single injection of warfarin (2.5 mg/kg, s.c.). The plasma and liver vitamin K1 levels gradually decreased after warfarin injection, attaining the lowest values at 2-3 hrs and remaining low for 48 hrs. They then returned to the control levels at 72 hrs. The changes in vitamin K1 epoxide levels were opposite, with an increase being seen soon after the warfarin injection, the highest values at 3 hrs and a gradual decrease to the initial levels occurring subsequently. The combined levels of vitamin K1 plus vitamin K1 epoxide, however, remained almost constant in both plasma and liver after the warfarin injection. The liver vitamin K epoxide reductase activity decreased to its lowest level soon after the injection and then gradually increased after 12 hrs, but the activity at 72 hrs was only about 30% of the initial activity. The plasma clotting factor levels gradually decreased after the injection, bottomed at 24 hrs and then began to increase, recovering almost to the initial levels at 72 hrs. A positive correlation was found between plasma and liver levels for both vitamin K1 and vitamin K1 epoxide, and the slope of the vitamin K1 epoxide curve was steeper than that for vitamin K1 in the warfarin-treated rats. A similar positive correlation was found for both vitamin K1 and vitamin K1 epoxide after vitamin K1 injection in normal untreated rats, but the slope of the vitamin K1 epoxide curve was much shallower. These results suggest that warfarin inhibits vitamin K epoxide reductase and decreases blood clotting factor synthesis, thus increasing plasma and liver vitamin K1 epoxide levels. A vitamin K epoxide reductase activity one third of that in normal rats is sufficient to maintain normal reduction of vitamin K1 epoxide and synthesis of blood clotting factors.

Inhibition of MAO activity, 3H-imipramine binding, 3H-paroxetine binding and 3H-5-HT uptake by human cerebrospinal fluid

Addition of small amount of human cerebrospinal fluid (CSF) inhibited both types of MAO in monkey brain mitochondria. The specific binding of 3H-paroxetine decreased remarkably with increasing CSF volumes, while 3H-imipramine binding was slightly inhibited. Scatchard analysis of 3H-paroxetine binding in the presence and absence of CSF indicated that the inhibitory effect was associated with a decreased Bmax without an appreciable change in Kd. Addition of CSF induced an inhibition of uncompetitive 3H-5-HT uptake to monkey cerebral membranes. These results indicate that the materials in human CSF inhibit 3H-paroxetine binding, and modulate the uptake system for 5-HT.

Comparative studies on semicarbazide-sensitive amine oxidase in heart and plasma of rats treated with hepatotoxin allyl formate

1. After allyl formate (AF) was administered to the rats, the existence of semicarbazide-sensitive amine oxidase (SSAO) in rat identified. 2. When the heart homogenate and plasma of AF-administered rat were pretreated with 10(-3) M clorgyline and deprenyl, the Km value for benzylamine of rat heart was same as the value of plasma. 3. The existence of SSAO in plasma of AF-administered rats were identified by IEF-gel electrophoresis. The pI values of SSAO in heart and plasma were a single peak of 5.0. 4. SSAO released from the rat heart in response to AF, although the other origins of this enzyme are unknown.

Immunohistochemical localization of Na+, K+-ATPase in human normal and malignant pancreatic tissues

Localization of Na+, K+-ATPase in the human pancreas was investigated immunohistochemically using rabbit antisera against Na+, K+-ATPase of the human kidney. The reaction product existed only on the luminal surfaces of both centroacinar and ductal cells in normal pancreatic tissue, whereas in chronic pancreatitis the localization of Na+, K+-ATPase was found frequently on the luminal surfaces of both centroacinar and ductal cells, and on the basolateral surfaces of some ductal cells. However, in acinar cells, the distribution of Na+,K+-ATPase was not detected in either the normal pancreas or chronic pancreatitis. In pancreatic carcinoma tissues, Na+,K+-ATPase existed very rarely in malignant cells. These results indicate that Na+,K+-ATPase is immunohistochemically localized on the membranes of centroacinar and ductal cells of the human pancreas, and that the antigenicity of Na+,K+-ATPase in pancreatic carcinoma cells differs from that in normal cells.

The bioavailability of sulpiride taken as a film-coated tablet with sodium bicarbonate, cimetidine, natural orange juice or hydrochloric acid

The bioavailability of sulpiride taken in film-coated tablet form with sodium bicarbonate or cimetidine or with natural orange juice or diluted hydrochloric acid was studied. A commercial sulpiride film-coated tablet (100 mg/T) treated with polyvinylacetal diethylaminoacetate (AEA), which remain undissolved at pH above 4-5, was given to four healthy volunteers who had fasted overnight. The subjects were divided into two groups, those showing high and low bioavailability of sulpiride from an AEA film-coated tablet. The two high bioavailability subjects took one tablet (100 mg) with 100 ml of water (1) alone, (2) together with 1 g of sodium bicarbonate or (3) during concurrent dosing with cimetidine, 200 mg three times a day. The two low bioavailability subjects swallowed one tablet with 100 ml of (1) water, (2) natural orange juice, or (3) diluted hydrochloric acid. Urine samples were collected over a 48-h period following sulpiride administration to determine sulpiride concentrations by HPLC. The bioavailability was estimated from the cumulative amount excreted unchanged in urine over 48 h (Du48). In the high bioavailability subjects, the bioavailability of sulpiride markedly decreased with the coadministration of sodium bicarbonate or cimetidine compared to when the tablet was taken alone. In the low bioavailability subjects, the bioavailability remarkably increased with the concomitant intake of orange juice or diluted hydrochloric acid over that with only water. These results suggest that the bioavailability of sulpiride from AEA film-coated tablet is influenced by the individual's gastric acidity and by coadministered drug and drink which affect gastric acidity.

Amine oxidase released into plasma of rats treated with hepatotoxin allyl formate

Amine oxidase activity in plasma of rats were investigated after pretreatment with the perilobular hepatotoxin allyl formate (AF). Amine oxidase activities in plasma elevated after administration of AF 0.1 ml/kg i.p. to male rats with 1 microM and 100 microM benzylamine (Bz), 10 microM beta-phenylethylamine (beta-PEA) and 100 microM serotonin (5-HT) as substrates. But the complete inhibition of amine oxidase activities with 5-HT and beta-PEA were not observed by clorgyline as A-form MAO inhibitor and deprenyl as beta-form MAO inhibitor. The deamination of 1 microM Bz was not inhibited at high concentrations of these MAO inhibitors, while it was inhibited at low concentrations of phenelzine and semicarbazide. On the other hand, the deamination of 100 microM Bz was highly sensitive with these MAO inhibitors, while it was less sensitive with phenelzine and semicarbazide as compared with 1 microM Bz. Then, the Km values of amine oxidase in plasma of AF-administered rats with Bz as substrate were determined from Lineweaver-Burk double reciprocal plots. Two Km values for Bz of high and low Bz concentration in amine oxidase in plasma of AF-administered rats were obtained. However, this Km value of low Bz concentration was not obtained from liver mitochondria and microsomes of control rat and AF-administered rats. The Km value for beta-PEA of MAO in plasma of AF-administered rats was the same as the values of rat liver mitochondrial MAO. These results indicate that native mitochondrial MAO was released from the liver, and two or more distinct amine oxidases were released from other organs in response to AF.

Monoamine oxidase activity in the liver of rats given diethylnitrosamine

The effect of diethylnitrosamine (DEN), a well known experimental carcinogen, MAO-A and MAO-B activity of rat liver was investigated. The oxidations of both 5-HT (MAO-A) and beta-PEA (MAO-B) were inhibited by DEN in vitro. DEN is reversible inhibitor, after enzyme-inhibitor preincubation. MAO-B activity in rat liver was decreased by continuous administration of 50 ppm DEN for several definite periods to rats. The almost 2-fold increase in the ratio of MAO-A/MAO-B was observed in rat liver mitochondria and microsomes. When 5-HT was used as substrate, there was no significant difference of Km and Vmax values between mitochondrial preparations from livers of control and DEN fed rats. However, when the mitochondria from livers of DEN fed rats were used as enzyme preparation, Vmax decreased to about 47% of the control with beta-PEA as substrate. DEN might change the proportions of the multiple forms of MAO activity in tumor cells.

Effects of bifemelane hydrochloride on various cholinergic markers in cortical and subcortical regions of aged rats

The effects of bifemelane hydrochloride (BF) upon various cholinergic markers, muscarinic receptors, acetylcholinesterase (AChE) and choline acetyltransferase (CAT), in the aged rat brain were examined. Marked reduction of the density of muscarinic receptors (Bmax) as well as AChE and CAT activity concomitant with aging was observed. Administration of BF in daily doses of 10 mg/kg for 4 weeks to aged rats significantly decreased the apparent dissociation constant (Kd) for QNB in muscarinic receptors in the forebrain, but did not affect the value of Bmax. CAT activity also increased significantly compared with that of control aged rats, but administration of BF did not alter AChE activity. These results indicate that long-term treatment with BF enhances the affinity of muscarinic receptors for QNB as well as CAT activity and that BF may have therapeutic application in the treatment of CNS cholinergic dysfunctions.

Effect of vitamin K deficiency on urinary gamma-carboxyglutamic acid excretion in rats

Since gamma-carboxyglutamic acid (Gla) in Gla-containing proteins is stoichiometrically excreted into urine as free Gla, urinary Gla excretion is believed to reflect the rate of synthesis and degradation of vitamin K-dependent proteins and the utilization of vitamin K in body. We studied the daily changes in urinary Gla excretion and plasma vitamin K-dependent clotting factor levels in rats fed vitamin K-deficient diets followed by subcutaneous injection of vitamin K1 or after the oral administration of Warfarin. Urinary Gla excretion in normal rats fed a standard diet that contained about 500 ng of vitamin K1 per gram of diet was 2.35 +/- 0.25 mumoles/day, but the level in rats fed a markedly vitamin K-deficient diet (less than 5 ng/g) decreased to 1.40 +/- 0.14 mumoles/day. When rats were fed a moderately vitamin K-deficient diet (20-50 ng/g), plasma vitamin K-dependent clotting factor levels decreased significantly, but urinary Gla excretion did not decrease. Warfarin, a vitamin K antagonist, caused a significant decrease in urinary Gla excretion and plasma clotting factor levels. When vitamin K, (200 micrograms/kg) was injected subcutaneously in rats fed a markedly vitamin K-deficient diet, the plasma vitamin K-dependent clotting factor levels recovered quickly to normal, but urinary Gla excretion showed only a partial recovery to 1.74 +/- 0.15 mumoles/day. These results indicate that urinary Gla excretion decreases in vitamin K deficiency, but changes in urinary Gla excretion do not reflect vitamin K deficiency in rats as sensitively as changes in the prothrombin time and plasma K-dependent clotting factor levels.

[Five cases of rectal cancer showing remarkable response to suppository administration of tegafur]

Five cases of rectal cancer, one male and 4 females, were preoperatively treated with Tegafur suppositories at 1,500 mg per day, for 8 to 21 days (mean, 14 days). These tumors were 2 early cancers and 3 advanced cancers, the configuration of which were one IIa type, one IIa + IIc type and 3 Borrmann 2 types. Their size ranged from 1.3 to 4.2 cm in diameter. Curative resections were performed in all cases, and the examination of the resected specimen revealed marked effects of Tegafur as follows: 1) Reduction of tumor size, 2) disappearance of cancer wall, 3) degeneration of cancer cells and destruction of cancer glands accompanied by fibrous stroma with infiltration of lymphocytes and plasma cells, 4) formation of xanthogranulomatous tissue with foamy histiocytes, which were characteristic findings showing that cancer tissue had been present there. As a result, rectal cancer clearly showed remarkable response to suppository administration of Tegafur for only about two weeks, if the tumor cells were sensitive to the drug.