[Relationship between arterial blood gas tensions and a clinical scoring system in asthmatic patients]

We evaluated the relationship between blood gas tensions and a clinical scoring system in pediatric asthma patients, who were divided into two groups according to their ages (under 5 years and over 6 years). The clinical score was derived from Mitsui, which was constructed using reference only to clinical symptoms and signs. The clinical scores had a statistically significant correlation with PaO2, PaCO2, SaO2 and pH in both groups. However there were fluctuations between clinical score and blood gas tensions. A low clinical score did not exclude hypoxemia. There were no statistical differences between the two groups, but subjects under 5 years old showed better correlation. This scoring system is useful to evaluate the degree of asthma attack, especially severe attack, both in younger (under 5 years) and older (over 6 years) asthmatic patients.

Effect of a peptide leukotriene antagonist, ONO-1078 on antigen-induced airway microvascular leakage in actively sensitized guinea pigs

We examined the effect of ONO-1078, a peptide leukotriene antagonist, on antigen-induced airway microvascular leakage in ovalbumin-sensitized guinea pigs. When guinea pigs were pretreated with mepyramine, ovalbumin challenge increased vascular permeability to Evans blue dye in trachea, main bronchi and intrapulmonary airways. Oral administration of ONO-1078 significantly reduced microvascular leakage in intrapulmonary airways at doses more than 3 mg/kg, but not in trachea. Moreover, oral administration of ONO-1078 significantly reduced SRS-A mediated microvascular leakage into all airway tissues and was more effective in intrapulmonary airways at 3 mg/kg. Simultaneously, ONO-1078 also inhibited SRS-A mediated bronchoconstriction. On the other hand, azelastine (10 mg/kg, p.o.), an anti-asthma agent, failed to inhibit microvascular leakage into the airways. These results suggest that peptide leukotrienes may be important mediators of airway microvascular leakage, and that the inhibitory effect of ONO-1078 on antigen-induced airway microvascular leakage in addition to the blockade of bronchoconstriction may have therapeutic implications for bronchial asthma.

Airway responses to repeated exercises detected by krypton-81m in asthmatic children

A repeated exercise program was used to test 7 asthmatic children for changes in ventilation. These changes were examined by continuously inhaled Krypton-81m and compared in subjects with positive and negative refractoriness, as defined by forced expiratory volume in 1 second (FEV1). Three of the seven patients showed significant refractoriness (% reduction in FEV1 > 50%). After the first exercise, they showed one or two ventilation defects which improved after the second exercise. The patient with incomplete refractoriness showed similar results. On the contrary, subjects without refractoriness showed several ventilation defects which fluctuated after the second or third exercise program. One defected area improved after the second exercise session, but deteriorated after the third; and another area deteriorated after the second exercise and improved after the third. It was concluded that approximately half of the patients were refractory in view of FEV1, but that they were all refractory in view of regional ventilation 81mKr images.

[The respiratory function in children with collagen disease]

Respiratory function tests were performed on 60 children with collagen disease. Twenty-seven cases (45%) showed abnormalities in the respiratory function. These abnormalities were restrictive in 14 cases (52%), obstructive in 6 cases (22%), and mixed type in 7 cases (26%). Eight out of 14 SLE patients (57%) showed abnormalities of various types. Abnormalities were seen in 9 out of 25 JRA patients (36%) including 6 cases (67%) with restrictive type changes. Four out of 6 MCTD (67%) and 3 out of 9 DM (33%) patient showed functional abnormalities. Most of patients with these two types of collagen disease showed restrictive changes. Investigations performed by a research group of the Ministry of Health and Welfare showed the incidence of restrictive type changes (% VC less than 80) in adult patients of collagen disease to be in the following descending order: PM/DM greater than PSS greater than MCTD greater than SLE. Though small in number, our investigation revealed that a considerable proportion of MCTD and SLE patients showed restrictive changes in respiratory function. In evaluating the clinical course of the disease, it was thus considered to be important to follow up the progress of respiratory functions in children with collagen disease.

[Reactivity of sevoflurane with carbon dioxide absorbents--comparison of soda lime and Baralyme]

The reactivity of sevoflurane with carbon dioxide absorbents, soda lime and Baralyme which are commercially available carbon dioxide absorbents, was studied. A closed circuit system which was made only for this investigation was set up without rubber. Sevoflurane 5% was circulated for 17 hours. The circulated gas was analyzed by gas chromatography (GC) and degradation products were identified by a gas chromatography-mass spectroscopy (GC-MS) as fluoromethyl 2-methoxy-2, 2-difluoro-1-(trifluoromethyl) ethyl ether, fluoromethyl 2-methoxy-2-fluoro-1-(trifluoromethyl) vinyl ether, and its isomer. These degradation products of sevoflurane from soda lime and Baralyme were the same substances. The rate of degradation by soda lime was 0.88% +/- 0.306, while that by Baralyme was 3.40% +/- 0.501. Baralyme decomposed sevoflurane about four times more than soda lime. There are two possible explanations for these results. One is the Baralyme contains more potassium hydroxide than soda lime. The other is that soda lime absorbs sevoflurane more because it contains more silica.

[Effects of procaterol on arterial blood gas and pulmonary function in asthmatic children]

We examined the changes in arterial blood gas, FEV1 and V50 after the inhalation of procaterol on 19 occasions in 16 asthmatic children. The initial value of PaO2 had statistically significant correlation with the initial values of %FEV1 and %V50. PaO2 fell down in 11 out of 19 (57.9%) and remarkably decreased more than 5 mmHg in 6 out of 19 (31.6%). The fall in PaO2 was most significant at 5 min after the inhalation in almost subjects. The changes in PaO2 after the inhalation had good correlation with the initial value of %FEV1 and %V50. The initial values were quite lower in the patients with decreased PaO2 more than 5 mmHg than those with increased PaO2. Severe patients showed statistically low values of the initial PaO2 and %V50 and showed a fall in PaO2 after inhalation compared with moderate patients. An increase in A-aDO2 elicited that deteriorations of V/Q ratio caused a decrease in PaO2 after inhalation. There were no significant changes in heart rates and no complaints of nausea, headache or tremor.

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.

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.

Hypoxia prevents seizures and neuronal damages of the hippocampus induced by kainic acid in rats

The effects of hypoxia on the epileptic seizures and neuronal damages induced by kainic acid were studied in rats using hypoxic chamber equipment. Rats treated with kainic acid and placed in atmospheric pressure showed typical limbic seizures and regressive neuronal changes in CA3 and CA4 of the hippocampus, while those kept in a hypoxic chamber with 8.5% O2 and 91.5% N2 showed moderate hypoxia and a slight decline of mean arterial blood pressure. In these hypoxic rats, seizures were completely prevented and there was remarkably less regressive neuronal injury of the hippocampus. Thus hypoxia has a rather ameliorative effect on the occurrence of seizures and excitotoxic neuronal injuries induced by kainic acid. The contribution of oxygen radicals and endogenous adenosine to preventing excitotoxic neuronal damages by kainic acid was discussed.

Chromosomal transformation in Saccharomyces cerevisiae with DNA isolated by pulse field gel electrophoresis

We isolated and purified yeast chromosome DNA molecules using pulse field gel electrophoresis (PFG). The isolated DNA had nearly the same size as the native chromosomal DNA on PFG. We could directly transform Saccharomyces cerevisiae yeasts with it, and obtain transformants that were selected by complementation of several markers. They had new chromosome DNA bands observed on PFG. The new chromosome was very stable during mitosis and mating processes, and each of the three homologous chromosomes in the derivative zygotes of transformants was separated equally in daughter cells.

[The application of flow cytometry in analysis of erythrocyte antigen determinants]

FCM has become an invaluable technique in a variety of clinical and research applications. Then, FCM is used for quantitative analysis of human erythrocyte antigens using Spectrum III. Antibody sensitizations give rise to erythrocyte agglutination making the FCM analysis of a single cell impossible. However, such agglutination could be prevented by some of erythrocyte fixations with PFA and DMS. To make examinations in an optimal concentration of primary antibodies was important for FCM assay. FCM was used to detect small percentage of D antigen positive cell contaminated in negative samples, subsequently positive cells were finally detected in 0.2%. This assay was utilized on a recipient of M/N mismatched allogeneic BMT, and an accurate proof of engraftment was obtained. Relationship of the numbers of antigen determinants and immunofluorescence intensities might be in linear correlation by log-log transformation. The fluorescence intensities of D antigen were analyzed for different rhesus phenotypes and variants such as Du and -D- cells. Lower fluorescence intensities on Du and higher intensities on -D- cell could be seen comparing with average value of D positive cells. However, no relationship between rhesus phenotypes and anti-D immunofluorescence intensities was observed. These findings suggest that FCM is useful and accurate technique for measuring relative antigen determinants of erythrocyte.

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.

Cloning and nucleotide sequence of the KHR killer gene of Saccharomyces cerevisiae

The KHR gene cloned from a genomic library was on 4.7-kbp DNA fragment and was inserted into YCpG11 vector (KHR-YCp) and YEp vector (KHP-YEp). Transformants with KHR-YEp could secrete 3-4 times as much killer toxin into the media as the donor strain. The complete nucleotide sequence of the KHR gene was analyzed. It was found that the KHR gene consisted of 888 bp. It was suggested that this protein was processed before being secreted into the media, because its molecular mass presumed from the nucleotide sequence was larger than that of the mature killer toxin.

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.

Isolation and properties of a chromosome-dependent KHR killer toxin in Saccharomyces cerevisiae

A strain of the yeast Saccharomyces cerevisiae coding for KHR on the chromosome secreted a toxin that kills sensitive yeasts. The transformants of multicopy vectors carrying the KHR gene could secrete 3-4-fold the killer toxin of the donor strain. This toxic substance was purified 80-fold in specific activity from the culture filtrate by gel filtration and hydrophobic column chromatography. The purified toxin gave a single protein band with molecular mass of 20 kDa on SDS-PAGE and had an isoelectric point of pH 5.3. The toxin had novel killer activity against Candida glabrata and S. cerevisiae, but did not affect bacteria, fungi, or other yeasts.

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.

Lactamimides: a novel chemical class of calcium antagonists with diltiazem-like properties

The effects of a series of lactamimides on [3H]d-cis-diltiazem binding to rat brain membranes, on [3H]nitrendipine binding to cardiac membranes, and on calcium-induced contractions in depolarized guinea pig taenia and ileum preparations were examined. Several of the lactamimides examined displaced [3H]d-cis-diltiazem binding and antagonized, in a competitive fashion, calcium-induced contractions. Over the series of lactamimides, there was a highly significant, positive linear correlation (r = 0.87, P less than 0.001) between their potency to displace [3H]d-cis-diltiazem and their potency to antagonize calcium-induced contractions in the depolarized taenia and ileum preparations. Of the lactamimides examined, MDL 16,582A [N-(2,2-diphenylpentyl)azacyclotridecan-2-imine. hydrochloride] had potency equivalent to d-cis-diltiazem with pA2 values of 7.27 and 7.38, respectively, against calcium-induced contractions in the guinea pig ileum. These lactamimides are a novel chemical class displaying diltiazem-like calcium antagonist properties.

A case of exercise-induced anaphylaxis: evidence of an association with the complement system

We studied a 17-year-old girl with exercise-induced anaphylaxis (EIA). She experienced 10 episodes of EIA which demonstrated cutaneous, digestive and cardiorespiratory symptoms. This subject exhibited elevation in plasma histamine (13.3 ng/ml) and decrease in CH50 (17 U/ml) and C3 (70 mg/dl) after naturally induced EIA. On remission day CH50 (26 U/ml), C3 (83 mg/dl) and C4 (15 mg/dl) were of relatively low values. Her mother demonstrated the same tendency with a low level of C4 (14 mg/dl), and this suggested an underlying genetic disorder in the complement system. Exercise challenge could not elicit EIA symptomatically but showed fluctuation of CH50. The triggering mechanism of EIA was unclear; however there is a possibility that complement plays an important role in EIA.

[Neurochemical studies on bifemelane, a new cerebral function improver. I. Effects of bifemelane on the function of neurotransmission-related enzymes and receptors in rat brain]

We examined neurochemically the effects of bifemelane (BF) on muscarinic ACh (mACh-R) and beta-adrenergic receptors (beta-AdR) and imipramine binding sites and the activities of acetylcholinesterase (AChE), choline acetyltransferase (CAT) and monoamine oxidase (MAO) in the P2 fractions of rat brain, ex vivo and in vitro. Male rats were given daily injections of 10, 30 mg/kg BF, p.o., for a period of 4 weeks. The Kd and Bmax values for mACh-R in the rat forebrain by administration of 10, 30 mg/kg BF decreased significantly compared with that of the control, although the Kd and Bmax values for beta-AdR and imipramine binding sites were almost identical. The Km and Vmax values of A- and B-form MAO decreased in rats that had been administered 30 mg/kg BF for 4 weeks. The binding of 3H-QNB (quinuclidinyl benzilate) on mACh-R, 125I-CYP (iodocyanopindolol) on beta-AdR and 3H-imipramine on imipramine binding sites decreased by 60, 20 and 70% in the presence of 1 microM BF, respectively, while the addition of 1 microM BF inhibited MAO activity by about 50%. However, CAT and AChE activities were not inhibited by BF.

Endogenous monoamine oxidase inhibitor-like substances in monkey brain

The extraction and partial purification of endogenous "monoamine oxidase (MAO) inhibitor-like" material from the monkey brain are described. The endogenous material (F-1 and F-2) obtained after Bio-Gel P-2 gel filtration and silica column chromatography inhibited MAO in the monkey brain mitochondria toward 5-hydroxytryptamine (5-HT), beta-phenylethylamine (beta-PEA), tyramine and dopamine as substrates. The inhibitory effects of F-1 and F-2 were non-linear concentration dependent, and F-1 non-competitively inhibited A-form MAO, while F-2 inhibited A-form MAO competitively and inhibited B-form MAO non-competitively. These substances were more potent inhibitors of A-form than of B-form MAO. F-2 was heat stable but liable to the treatment with pepsin and trypsin. F-1 was not inactivated by heat treatment and digestion with pepsin and trypsin. F-1 may be a low molecular weight (less than 1350) compound, including certain monoamines or their metabolites or other unidentified compounds, while F-2 was a low molecular weight (about 2500) peptide.

[Infantile JRA and ACTH therapy]

Systemic juvenile rheumatoid arthritis is characterized by chronic arthritis and associated with extra-articular features. Although JRA may present at any age throughout childhood, the onset of symptoms during the first year of life is relatively uncommon. The diagnosis of infantile JRA is difficult because of poor complaints. We had a 7-month-old female, first onset at 6 months of age for daily "spiking" fever and skin rash, subsequently developed signs of systemic rheumatoid arthritis. Although aspirin or other nonsteroidal anti-inflammatory agents were used for the therapy, no significant effect was obtained. Prednisone was administered to control arthritis and serious systemic features, however no satisfactory effect was shown. In this patient a single morning alternate-day shot of ACTH-Z (4 units) was employed, and this regimen showed significant effect to control her clinical symptoms. It may be necessary to add a small dose of ACTH-Z for control in some cases of infantile JRA patient compared to adult cases.

A cytoplasmic thyroid hormone binding protein: characterization using monoclonal antibodies

We have previously purified a cellular thyroid hormone binding protein (p58) from a human carcinoma cell line [Kitagawa, S., Obata, T., Hasumura, S., Pastan, I., & Cheng, S.-y. (1987) J. Biol. Chem. 262, 3903-3908]. In the present study, the binding characteristics, the molecular properties, and subcellular localization of p58 were further characterized. Binding of the purified p58 to thyroid hormones was examined. Analysis of binding data indicates that p58 binds to 3,3',5-triiodo-L-thyronine (T3) with a Kd of 24.3 +/- 0.3 nM and n = 0.71. p58 binds to L-thyroxine similarly as to T3. However, D-T3 and reverse-T3 bind to p58 with an affinity 4- and 20-fold less than that of T3, respectively. By use of the purified p58 as an immunogen, two hybridomas, J11 and J12, secreting monoclonal antibodies to p58 were isolated; both antibodies belong to the IgG1K subclass. J12 recognizes p58 from human, monkey, dog, hamster, and rat, but not mouse. J11 exhibits a similar species specificity except that it does not react with p58 from hamster. With these antibodies, p58 was found to be not posttranslationally modified by glycosylation, sulfation, or phosphorylation. It has a cellular degradation rate t1/2 congruent to 2.1 h. Immunocytochemical studies indicate that p58 is located in the nonmembranous cytoplasm (cytosol). These results are consistent with subcellular fractionation studies which show that greater than 95% of J11 and J12 reactivity and T3 binding activity can be found in the 110,000g supernatant.

Effect of diethylnitrosamine on monoamine oxidase in rat liver

The effect of diethylnitrosamine (DEN), a well-known experimental carcinogen, toward MAO-A and MAO-B activity of rat liver was investigated. The oxidations of both beta-PEA (MAO-B) and 5-HT (MAO-A) were inhibited by DEN. The K1 values of DEN in the inhibition of rat liver MAO-A and MAO-B activity were determined. The kinetic data show that DEN is a competitive, MAO-B selective inhibitor and its inhibitory effect on MAO-B is about 4-fold more potent than that on MAO-A. DEN might change the proportions of the multiple forms of MAO activity in tumor cells.

Changes in amine oxidase in plasma of rats treated with hepatotoxins

When allyl formate (AF) was administered to rats, the marked elevation of B-form MAO activity in plasma was found with beta-PEA as a substrate. In contrast, in the case of carbon tetrachloride (CCl4), A-form MAO activity elevated predominantly. The deaminations of 5-HT and beta-PEA in these plasma treated with AF or CCl4 were not inhibited completely by a high concentration of MAO inhibitor, deprenyl or clorgyline. These results indicate that there may be two or more distinct amine oxidases released from the liver and other organs in response to CCl4 or AF.

Drug effects on exercise-induced late asthmatic responses

Disodium cromoglycate, prednisolone, beclomethasone and salbutamol were administered prior to the cycle ergometer exercise task separately to different groups of children with exercise-induced dual asthmatic reaction. Pre-treatment with disodium cromoglycate of ten asthmatics totally inhibited the dual reaction. Prednisolone treatment of eleven asthmatics and beclomethasone treatment of five asthmatics did not inhibit the early response but only the late response. Salbutamol treatment of ten asthmatics mainly inhibited the early phase reaction. Changes in neutrophil chemotactic activity correlated with airflow limitation in the disodium cromoglycate and prednisolone study, however, there were some discrepancies between the changes in FEV1 and neutrophil chemotactic activity in the beclomethasone and salbutamol studies. These findings suggest that exercise-induced dual asthmatic reaction are modified by disodium cromoglycate, prednisolone, beclomethasone or salbutamol in a mechanism which may be different in each drug and that there are similarities in the inflammatory responses in antigen- and exercise-induced dual asthmatic responses.

Antibodies against the human cellular 3,3',5-triiodo-L-thyronine-binding protein (p 58)

High-titer antibodies against a cellular thyroid hormone-binding protein (Mr 58,000, p58) were developed by a special immunization method. To enhance immune responses, this method uses a boosting protocol in which repeated injections of small amounts of antigen are administered at 2-day intervals. Antibodies were detected 1 week after the last injection of antigen by ELISA, Western dot blotting and immunoprecipitation. The anti-p58 antibodies recognized p58 which is bound to the thyroid hormone. With the availability of anti-p58 antibodies, it has become possible to study cellular localization and function.

Modulation of gamma-aminobutyric acid-stimulated chloride influx by bicycloorthocarboxylates, bicyclophosphorus esters, polychlorocycloalkanes and other cage convulsants

gamma-Aminobutyric acid (GABA) stimulated 36Cl- influx into membrane vesicles from rat cerebral cortex at 3 to 300 microM in a concentration-dependent manner with near maximum response at 100 microM. Inhibitory potencies for this GABA (100 microM)-dependent 36Cl- uptake were determined for 16 cage convulsants including 10 bicycloorthocarboxylates and 3 bicyclophosphorus esters and for 8 polychlorocycloalkane insecticides. Inhibition by derivatives of t-butylbicycloorthobenzoate (TBOB) and t-butylbicyclophosphorothionate (TBPS) depended on the substituents at both positions 1 and positions 4. Among them, the 4-cyano-phenyl analog of TBOB was the most potent inhibitor with an IC50 value of 40 nM. Other cage convulsants such as picrotoxinin, tetramethylenedisulfotetramine and p-chlorophenylsilatrane were less potent than TBOB and TBPS. The potencies of bicycloorthocarboxylates, bicyclophosphorus esters and other cage convulsants in inhibiting GABA-stimulated 36Cl- uptake by rat cerebral cortex were significantly correlated with those in inhibiting [35S]TBPS binding to the human and mouse brain receptors (r = 0.96, P less than .01). There also was a significant correlation between the potencies of the polychlorocycloalkanes examined in inhibiting GABA-stimulated 36Cl- uptake and [35S]TBPS binding to the mouse brain receptor (r = 0.94, P less than .01). In these correlations, the polychlorocycloalkanes appear to fall on a different line than that for the bicycloorthocarboxylates, bicyclophosphorus esters and other cage convulsants. Both the cage convulsants and the polychlorocycloalkanes are considered to act at convulsant sites coupled functionally to the GABA receptor chloride ionophore complex and thereby to modulate allosterically or directly the GABA-gated chloride channel leading to their toxic action.

Thyroid hormone down-regulates p55, a thyroid hormone-binding protein that is homologous to protein disulfide isomerase and the beta-subunit of prolyl-4-hydroxylase

We have previously characterized a cellular thyroid hormone-binding protein (p55) that is found concentrated on the lumenal face of the endoplasmic reticulum and nuclear envelope (Cheng, S.-y., Hasumura, S., Willingham, M.C., and Pastan, I. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 947-951). To understand the role p55 plays in thyroid hormone action, we examined the regulation of p55 by 3,3',5-triiodo-L-thyronine (T3). Rat pituitary tumor GH3 cells cultured in regular medium, thyroid hormone-depleted medium (Td medium), or Td medium supplemented with 50 nM T3 (Td + T3 medium) were metabolically labeled with [35S]methionine and immunoprecipitated with antibodies against p55. Treatment with T3 caused a fall in p55 levels. Poly(A+) RNA from cells cultured in regular, Td, or Td + T3 medium was hybridized to a cDNA from p55. T3 withdrawal or addition had no effect on p55 mRNA levels. Furthermore, the initial rates of synthesis of p55 from cells cultured in regular, Td, and Td + T3 were found to be similar. However, analysis of the decay curves from cells in which p55 was pulse-labeled with [35S]methionine indicated that p55 is 2-fold less stable in T3 containing medium. These results indicated that down-regulation of p55 by T3 occurs at the post-translational level. Since DNA sequence analysis indicates that p55 is identical to protein disulfide isomerase and the beta-subunit of prolyl-4-hydroxylase, T3 may mediate its effects on the synthesis, secretion, and/or transport of proteins via p55.

New potent antagonists of leukotrienes C4 and D4. 1. Synthesis and structure-activity relationships

(p-Amylcinnamoyl)anthranilic acid (3a) had moderate antagonist activities against LTD4-induced smooth muscle contraction on guinea pig ileum and LTC4-induced bronchoconstriction in anesthetized guinea pigs. Modifications were made in the hydrophobic part (cinnamoyl moiety) and the hydrophilic part (anthranilate moiety) of 3a. A series of 8-(benzoylamino)-2-tetrazol-5-yl-1,4-benzodioxans and 8-(benzoylamino)-2-tetrazol-5-yl-4-oxo-4H-1-benzopyrans were revealed to be potent antagonists of leukotrienes C4 and D4. Among both series, ONO-RS-347 (18k) and ONO-RS-411 (19h) were the most potent and orally active antagonists, respectively. Structure-activity relationships are discussed.

Modulation of GABA-stimulated chloride influx into membrane vesicles from rat cerebral cortex by triazolobenzodiazepines

The effects of triazolobenzodiazepines on GABA-stimulated 36Cl- uptake by membrane vesicles from rat cerebral cortex were examined. Triazolam and alprazolam showed a significant enhancement of GABA-stimulated 36Cl- uptake at 0.01-10 microM. On the other hand, adinazolam showed a small enhancement at 0.1-1 microM followed by a significant inhibition of GABA-stimulated 36Cl- uptake at 100 microM. The enhancement of GABA-stimulated 36Cl- uptake by 1 microM alprazolam was antagonized by Ro15-1788, a benzodiazepine antagonist, but the inhibition of this response by 30 microM adinazolam was not antagonized by Ro15-1788. These results indicate that triazolobenzodiazepines enhanced GABA-stimulated 36Cl- uptake through benzodiazepine receptors. High concentrations of adinazolam inhibit GABA-stimulated 36Cl- uptake which may be due to the direct blockade of GABA-gated chloride channel.

[Studies on antimicrobial concentrations of flomoxef in serum, pelvic dead space exudate, and pelvic organs/tissues]

To women undergoing radical and total hysterectomy, flomoxef (FMOX, 6315-S) in a dose of 2 g was administered by intravenous drip infusion over 1 hour and drug concentrations in serum and pelvic dead space exudate as well as pelvic organs/tissues were determined over time. The following results were obtained: 1. Serum concentrations of FMOX after intravenous infusion showed the peak value of 92.86 +/- 17.05 micrograms/ml at the end of infusion and then gradually decreased to 29.00 +/- 10.49 micrograms/ml in 1 hour and 1.16 +/- 1.08 micrograms/ml in 6 hours. 2. Concentrations in pelvic dead space exudate, which were 6.54 +/- 3.21 micrograms/ml at the end of intravenous infusion, gradually increased to 31.28 +/- 12.69 micrograms/ml in 30 minutes, and the peak of 35.21 +/- 13.29 micrograms/ml in 1 hour. Exudate concentrations gradually decreased to 11.10 +/- 6.64 micrograms/ml at 6 hours after infusion. 3. The serum concentration at the ligature of uterine artery was 103.21 +/- 51.69 micrograms/ml. Among concentrations in pelvic organ/tissues 37.17 +/- 18.20 micrograms/ml in uterine cervix was the highest, followed by 35.77 +/- 7.68 micrograms/g in portio vaginalis, 26.35 +/- 14.15 micrograms/g in tube, 21.62 +/- 12.15 micrograms/g in ovary, 20.56 +/- 9.82 micrograms/g in myometrium, and 16.45 +/- 8.10 micrograms/g in endometrium, in this order. 4. From an analysis of the two-compartment model, the maximum serum concentration was 92.81 micrograms/ml, which was very high. The time of 50% reduction of concentration in beta phase was 1.21 hours. In the pelvic dead space exudate, the maximum concentration was 32.38 micrograms/ml and the time of 50% reduction was 2.44 hours. The AUC was 147 micrograms.hr/ml in serum and 201 micrograms.hr/ml in the pelvic dead space. The shift to the pelvic dead space was 137% when AUC's were used as the basis of the comparison. 5. Clinically, FMOX was excellently effective against adnexitis caused by Peptostreptococcus asaccharolyticus, intrauterine infection caused by Staphylococcus aureus, cystitis caused by Klebsiella and Escherichia coli, vaginal stump infection caused by Streptococcus and E. coli and many other infections.

[Electrophoretic properties of mitochondrial monoamine oxidase in monkey liver]

Monkey liver monoamine oxidase (MAO) was predominantly the B-form enzyme from the observed differences in substrate specificities and differences in sensitivities to MAO inhibitors. It is known that a MAO inhibitor, pargyline, binds to MAO irreversibly in the molar ratio of 1:1. 3H-pargyline was used as a marker to determine the existence of MAO. The molecular weight of MAO in monkey liver mitochondria was investigated by SDS-polyacrylamide gel electrophoresis after solubilization of 3H-pargyline binding mitochondria with 6% sodium dodecyl sulphate (SDS). The subunit molecular weight was found to be 60,000. The molecular weight determined from the electrophoretic mobility on several concentrations of gels by disc gel electrophoresis in the absence of SDS was found to be 120,000. These results indicate that monkey liver mitochondrial MAO exists as a dimer. Isoelectric focusing of the enzyme after solubilization with 0.1% Triton X-100 and 0.75% Triton X-100 and 0.75% Lubrol showed that it had a pI value near 6.5. Similar pI values were obtained for enzyme preparations solubilized with 0.75% Triton X-100 after treatment with phospholipase A or methylethylketone. These results suggest that the pI value of MAO in monkey liver mitochondria does not depend on the properties of detergents used to solubilize the enzyme preparation.

Thyroid hormone action: induction of morphological changes and stimulation of cell growth in rat pituitary tumor GH3 cells

The effects of thyroid hormones on morphology and growth were studied in rat pituitary tumor GH3 cells using medium containing serum depleted of thyroid hormones. T3 and T4 induce the cells to change from a flattened fibroblastic morphology to a rounded or spindle-shaped morphology. The induction in morphological changes is T3 and T4 specific and dose dependent. Thyronine and rT3 are ineffective in inducing morphological changes; the half-maximal effective concentrations for T3 and T4 are 0.3 and 2 nM, respectively. Concomitantly, T3 stimulates cell growth, as indicated by a 2-fold reduction in doubling time and a 2-fold increase in mitotic rate. The growth-stimulating effect has the same analog specificity and dose dependency as the morphological changes. The morphological changes could be potentially useful for evaluating the biological effects of T3 and its analogs and in studying the mechanism of thyroid hormone action.

Evidence for existence of A and B form monoamine oxidase in mitochondria from dog platelets

It is known that platelet MAO appears to behave more like the B-form enzyme than the A-form enzyme based on inhibitor sensitivity and substrate specificity. However, dog platelets showed a different substrate specificity such as high activity with 5-HT and beta-PEA as substrates. Moreover, dog platelet MAO was sensitive to the drugs clorgyline and harmaline with 5-HT as the substrate, while it was sensitive to the drug deprenyl with beta-PEA as the substrate. These results also indicate the existence of two forms of MAO in dog platelets unlike in other platelets such as those from humans. A-form MAO from dog platelets was more stable against heat treatment at 55 degrees C than A-form MAO from dog liver and brain. On the other hand, there was no difference in the heat resistance of the three enzymes with beta-PEA as the substrate. After digestion with trypsin at 37 degrees C for 30 min, it was found that MAO from dog platelets, brain and liver were mostly inhibited with 5-HT as the substrate. In contrast, MAO in brain and liver were inhibited about 10%, but platelet MAO was inhibited about 50% with beta-PEA as the substrate. From these results, it is considered that dog platelet MAO exists as the two forms of the enzyme and has different enzymic properties in comparison with those of MAO from dog liver and brain mitochondria.