Hepatoprotective effects of KF-14363 were investigated in the following experimental models. KF-14363 inhibited the increase in serum glutamate pyruvate transaminase (GPT) dose-dependently, and a significant inhibition was noted at a dose of 30 mg/kg or more. KF-14363 significantly inhibited the D-galactosamine (D-gal)-induced increase in serum transaminase by oral administration at 250 mg/kg × 1 and 250 mg/kg × 2 doses. The D-gal-induced decrease in total protein levels was inhibited at doses of 100 mg/kg × 2 and 250 mg/kg × 2. KF-14363 (100 mg/kg or more) significantly inhibited the increase in liver triglyceride levels induced by DL-ethionine (250 mg/kg × 3). KF-14363 (300 mg/kg) significantly inhibited the D-gal plus lipo-polysaccharide-induced increase in GPT. At 100 mg/kg or less, however, an inhibiting tendency was noted, which was not significant as the values varied widely. KF-14363 (100 mg/kg) significantly inhibited Propionibacterium acnes plus lipopolysaccharide-induced mortality at 7 and 8 hr, and it showed an inhibitory tendency at 24 hr. These results demonstrate that KF-14363 is a compound that has a protective effect against the damage induced in various experimental liver injury models with different mechanisms.

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The effects of KF-14363 on active oxygen production and membrane stabilization were studied. KF-14363 did not affect hypotonic hemolysis (10% and 70%) and did not inhibit lipid peroxide production induced by t-butyl hydroperoxide at concentrations of less than 100 μM. KF-14363 significantly inhibited active oxygen production in peritoneal exudate cells (PEEL) stimulated with arachidonic acid, A23187 and carbon tetrachloride (CC14) at concentrations over 10 μM, 100 μM and 1 μM, respectively. It tended to inhibit formyl-methionyl-leucyl-phenylalanine-stimulated production of active oxygen in PEEC at concentrations over 10 μM, but there was no significant difference owing to large dispersion. Superoxide dismutase (SOD, 10⁴ U/ml) significantly inhibited CCl₄-stimulated production of active oxygen in PEEC. KF-14363 inhibited the radical production from CCl₄ in the presence of a 9000 ×g supernatant fraction of the rat liver which was administered with enzyme induction compounds (S9 mix). SOD (10⁴ U/ml) was not effective in this system. In conclusion, KF-14363 inhibited active oxygen production in PEEC induced by various stimulants and also the radical formation from CCl₄ in the presence of S9 mix solution.

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The present investigation deals with determining the efficacy of a high protein diet (HPD) in combating toxicity in albino rats of some organophosphorus compounds (OPCs) that follow dissimilar metabolic patterns in a living system. As assessed by an increase or decrease in the levels of some biochemical and nutritional parameters, the high protein diet containing 59% protein seems to have a beneficial effect in alleviating toxicity of low but prolonged doses of OPCs over the standard diet (SD) containing 19% protein. OPCs undergoing direct detoxication in a living system like diisopropyl phosphoro-fluoridate (DFP) appear to be more susceptible to HPD than those undergoing biotoxication like EPN (O-ethyl O-p-nitrophenyl phenyl-phosphonothioate) and malathion (S-(1, 2-dicarbethoxyethyl) O, O-dimethyldithio-phosphate).

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We investigated the cardiovascular effects of 2-octynyladenosine (YT-146), an adenosine A₂ agonist, in various mammalian preparations in comparison with adenosine and 2-chloroadenosine. YT-146, when intravenously administered, caused a dose-dependent decrease of blood pressure in anesthetized normotensive rats (with ED₃₀ values of 0.4 μg/kg), and YT-146 was 250 times more potent than adenosine. Whereas adenosine and 2-chloroadenosine decreased heart rate at approximately equihypotensive doses, YT-146 had no negative chronotropic effects at hypotensive doses. Orally given YT-146 (0.1-1 mg/kg) produced a potent and long-lasting anti-hypertensive effect in spontaneously hypertensive rats. YT-146 was 15.9 and 12.5 times more potent than adenosine in producing relaxation of isolated porcine coronary arteries and in increasing dog coronary blood flow, respectively. Although YT-146 was equipotent to adenosine in causing a negative inotropic effect in isolated guinea pig atria, it was less potent than adenosine in producing atrioventricular conduction block in guinea pigs. On the other hand, 2-chloroadenosine was 9.1, 1.8 and 2.4 times more potent than adenosine in lowering blood pressure, relaxing isolated porcine coronary arteries and increasing dog coronary blood flow, respectively. 2-Chloroadenosine was the most potent in producing cardiodepression, i.e., negative inotropy and atrioventricular conduction block in guinea pigs. From these results, we concluded that YT-146 is a potent coronary vasodilator and also a potent, orally active and long-acting hypotensive agent having less cardiac depressant activity.

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Ouabain- and furosemide-insensitive and ATP-dependent Cl^- uptake was demonstrated in rat renal membrane vesicles. Such a Cl^- uptake activity was prominent in cortical plasma membrane fractions with high activities of Cl^--ATPase and Na⁺, K⁺-ATPase. The membrane vesicles accumulated Cl^- in an osmotically reactive manner with the following sequence of nucleotide specificity: ATP > ITP > UTP > GTP > CTP., β, γ-Methylene ATP, ADP and AMP had no effect. ATP-dependent Cl^- uptake was markedly inhibited by a Cl^--ATPase inhibitor, ethacrynic acid (0.3 mM), but not affected by an H⁺-ATPase inhibitor, N, N'-dicyclohexylcarbodiimide (0.1 mM). These findings suggest that an ethacrynic acid-sensitive and ATP-driven Cl^- pump is present in the rat renal cortex.

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Tracheal relaxing effects and β₂-selectivity of TA-2005 were investigated by functional experiments and radioligand binding assay in guinea pigs in comparison with those of other β-agonists, isoproterenol, procaterol, formoterol and salbutamol. The relaxing activity of TA-2005 on histamine-induced contraction in the isolated trachea was most potent among the five agonists, and it was blocked by a β₂-selective antagonist (ICI 118, 551) but not by a β₁-selective antagonist (bisoprolol). The potency of the relaxing effect was in the order of TA-2005 (pD₂ = 9.79) > for moterol > procaterol > isoproterenol > salbutamol. The positive chronotropic effect of TA-2005 was similar to that of isoproterenol; and it was more potent than those of formoterol, procaterol and salbutamol in the isolated atria. The selectivity for tracheal muscle to atria of these agonists were in the order of procaterol ≥ formoterol > TA-2005 > salbutamol >> isoproterenol. A radioligand binding experiment using guinea pig lung and cardiac ventricle as β₂- and β₁-adrenoceptor sources, respectively, has also demonstrated that TA-2005 possesses extremely high affinity (IC₅₀ = 1.04 nM) and selectivity (38-fold) to β₂-adrenoceptors. By addition of GTP, the competition curve of [¹²⁵I]iodocyanopindolol shifted rightward, indicating the agonist property. These results confirmed that TA-2005 is a highly β₂-selective agonist that exerts a potent tracheal relaxing effect.

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Treatment of peritoneal macrophages with geraniin, isolated from Geranium funbergii, markedly induced the phagocytosis of living yeasts. Marked increases in phagocytosis and acid phosphatase activity in macrophage lysates were observed 24 hr after the beginning of geraniin treatment. As observed by electron microscopy, macrophages that had been treated for 24 hr with geraniin had a markedly thickened surface layer which was positive to ruthenium red, compared to the control cells. In addition, geraniin treatment of macrophages appeared to induce remarkably large mitochondria, more coated pits and prominent lysosomal granules. In conclusion, the stimulation of phagocytosis and acid phosphatase activity of macrophages by geraniin treatment may involve alterations of the plasma membrane and cytoplasmic reorganization.

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The 5-hydroxytryptamine (5-HT)₃ receptor binding assay using [³H]quipazine was examined. It was impossible to obtain specific [³H]quipazine binding with the membrane fractions from rat cortex prepared by the usual procedure. When the membranes were pretreated with detergent Triton X-100, the ratio of specific [³H]quipazine binding markedly increased, depending upon the concentration of Triton X-100 in the range of 0.01-0.1% (w/v). At a concentration of more than 0.05%, the specific binding reached a maximum of 55 to 60% of the total binding. The specific [³H]quipazine binding to the Triton X-100-treated membranes was reversible and was potently inhibited by several 5-HT₃ antagonists, while 5-HT₁, 5-HT₂ receptor antagonists and other receptor-specific ligands had no effect on the binding. Scatchard analysis indicated a single class of binding sites with a K_d of 0.62 nM and B_max of 97 fmol/mg protein. Thus, the Triton X-100-treated membranes retained the characteristics of 5-HT₃ binding sites, making it possible to use [³H]quipazine for a 5-HT₃ receptor binding assay with a high ratio of specific binding.

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Gastric mucosal blood flow (GMBF) was measured in the ex vivo stomachs of anesthetized rats simultaneously with mean arterial blood pressure (MBP), luminal pH and transmucosal potential difference (PD) in an attempt to characterize these responses induced by capsaicin. The stomach was mounted on a Lucite chamber, perfused with saline at the flow rate of 1 ml/min, and GMBF was measured by Laser flowmetry. Under these conditions, the pH, PD and GMBF were 3.5 to 4.0, -30 to -35 mV and 8-12 ml/min/100 g, respectively. Mucosal application of capsaicin (0.03-1 mg/ml for 10 min) increased GMBF in a concentration-dependent manner, without any change in PD, pH and MBP. The increased GMBF response caused by capsaicin was abolished by chemical deafferentation following systemic capsaicin injections (total dose: 100 mg/kg), significantly attenuated by pretreatment with indomethacin (5 mg/kg, s.c.) or ruthenium red (300 μg/kg, i.v.), but was not affected by spantide (100 μg/kg, i.v.), atropine (300 μg/kg, i.p.) or disodium cromoglycate (30 mg/kg, i.p.). In addition, when the mucosa was exposed to capsaicin repeatedly, this response showed a marked tachyphylaxis at a high concentration (6 mg/ml). These results suggest that intragastric capsaicin increased GMBF selectively through capsaicin-sensitive sensory neurons, and this action may involve endogenous prostaglandins.

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The antitumor effects of droloxifene (DROL, (E)-α-[p-[2-(dimethyl-amino)ethoxy]-phenyl]-α-ethyl-3-stilbenol), a new antiestrogen drug, on 7, 12-dimethyl-benz(a)anthracene (DMBA)-induced estrogen-dependent mammary tumors in rats were studied and compared with those of tamoxifen (TAM). Mammary tumors appeared from about 2 months after p.o. administration of DMBA to female rats, and all of them were estrogen receptor (ER) and progesterone receptor positive. DROL and TAM (p.o.) inhibited the growth of the tumors. Both drugs inhibited the binding of ¹²⁵I-estradiol-17β to ER in the cytosol of the tumor in vitro, and the effect of DROL was much stronger than that of TAM. When ³H-estradiol-17β (³H-E₂) was given s.c. to rats with the mammary tumors, ³H-E₂ accumulated in the tumors, uteri and vaginae in which the ER levels are known to be high, but was low in the heart, in which the ER levels are normally low. DROL and TAM decreased the levels of ³H-E₂ in the tumors, uteri and vaginae, but had no effect in the hearts. When DROL or TAM was given p.o. to rats daily for 7 consecutive days after administration of DMBA, they inhibited the induction of mammary tumors by DMBA. From these results, DROL inhibits the growth and the initiation of DMBA-induced mammary tumors by inhibiting the binding of estrogen to its receptor.

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Involvement of complement and platelet-activating factor (PAF) in zymosan-induced rat pleurisy was examined. Only a very low level of complement remained in the exudate at 1-5 hr after zymosan injection, indicating that complement activation had occurred during this period in the pleural cavity. When rats were injected with cobra venom factor (CVF) 24 hr prior to the zymosan injection to deplete complement, the exudate volumes at 0.5 and 5 hr after zymosan injection were significantly reduced. Furthermore, combined treatment with CVF and CV-6209, an antagonist of PAF, also significantly suppressed the exudation but to no further extent than the suppression by CVF alone, suggesting that the level of complement depletion achieved was sufficient to halt PAF synthesis/release. To see if complement activation is involved in PAF production, we examined the PAF production by resident leukocytes in response to zymosan in vitro. When pleural leukocytes were stimulated with zymosan in the presence of rat serum, PAF-like activity both in the medium and in the cellular fraction increased. If the serum was heat inactivated, no PAF-like activity was detected. These results suggest that initial activation of the complement system may occur in the pleural cavity by zymosan and that the activated complement may then stimulate the production of PAF, which in turn elicits the exudate.

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Mobilization of Ca⁺⁺ was estimated in single rabbit blood platelets with digital imaging microscopy. Concanavalin A (Con A) caused a rapid initial increase in intracellular concentration of Ca⁺⁺ ([Ca⁺⁺]_i) with a latent time of about 20 sec, followed by a sustained increase in [Ca⁺⁺]_i. This effect of Con A was antagonized by α-methyl-D-mannose, which already was shown to antagonize the inhibitory effect of Con A on 5-HT transport, indicating that this effect of Con A was also derived from its binding to cell surface glycoproteins. The presence of EGTA in the medium did not affect the initial rise, but inhibited the latter phase of sustained rise. Thus, Con A induced elevation of [Ca⁺⁺]_i was suggested to consist of two different processes: mobilization of Ca⁺⁺ from the intracellular storage sites and successive Ca⁺⁺ influx through Ca⁺⁺ channels. The effect of Con A on the 5-HT transport was tested in the presence of EGTA, a condition where no Ca⁺⁺ influx occurs. The results indicate that Con A induced inhibition of 5-HT transport was not influenced by EGTA in the medium. It is suggested that the effect of Con A on 5-HT transport might be exerted through the Ca⁺⁺ mobilization from its intracellular storage sites.

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Exposing mice to 24 and 4°C in alternate 1 hr periods in the day time and maintaining 4°C at night for several days decreases the tail clamp pressure required to evoke pain behavior. This model is referred to as SART (specific alternation rhythm of temperature) stress. An extract from inflamed skin of rabbits inoculated with vaccinia virus (neurotropin) clearly normalized the hyperalgesia in this SART stress model. To clarify the mechanism of the hyperalgesia in SART mice and the mode of the antinociceptive action of neurotropin in this model, the influence of systemically administered neurotransmitter related drugs was studied. 1) Neurotropin, 5-hydroxytryptophan and L-dihydroxyphenylalanine significantly normalized the decrease in nociceptive threshold, and muscimol tended to inhibit it in nociceptive threshold in SART stressed mice. 2) Haloperidol, phenoxybenzamine, reserpine, bicuculline, scopolamine, physostigmine and naloxone alone did not influence the nociceptive threshold in SART stressed mice. 3) The antinociceptive effect of neurotropin was significantly attenuated by p-chlorophenylalanine, haloperidol and phenoxybenzamine; and it was completely inhibited by reserpine. 4) Naloxone, bicuculline, scopolamine and physostigmine had no influence on the antinociceptive effect of neurotropin. These results suggest that hypofunction mainly of the monoaminergic systems contributes to hyperalgesia in SART stressed mice and that neurotropin produces the anti-nociceptive effect by restoring these neural functions.

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The effect of morphine on the binding of ³H-nitrendipine was studied in rat hippocampal preparations. Treatment of slices with morphine followed by the preparation of membrane fractions revealed the presence of low affinity binding sites. The effect of morphine was antagonized by naloxone. The effect was not observed when the membrane fraction was incubated with morphine. These results suggest that morphine changes the affinity of calcium for its channels and reduces its influx.

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Assessment of mouse paw edema induced by the passive allergic reaction was made by the previously reported dye-leakage method. The edema was induced by the injection of antiserum against ovalbumin into the paw, followed by the intravenous injection of ovalbumin 10 min before or 72 hr later. The latter reaction may be mainly mediated by heat-labile IgE. Both of the edemas were suppressed by pretreatment with mepyramine, methysergide, PAF-antagonists, or dexamethasone, and the latter suppressed by the lipoxygenase inhibitor AA-861, suggesting that histamine, serotonin, PAF, and leukotrienes are involved in exudate formation in these edemas.

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We evaluated the effect of the iron chelator deferoxamine on lipid peroxidation produced by the nephrotoxic antineoplastic drug cisplatin in rat kidney cortical slices. The addition of deferoxamine to the incubation medium prevented such lipid peroxidation in the incubated slices. Treatment of rats with deferoxamine inhibited the increase in lipid peroxidation caused by cisplatin in the medium. These results suggest that iron may be a causal agent of cisplatin-induced lipid peroxidation.

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