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T Miyamae

Publications and source records attributed to T Miyamae.

At least 37 records · Page 2Linked to original sources
PubMed1999

An L-dopaergic relay from the posterior hypothalamic nucleus to the rostral ventrolateral medulla and its cardiovascular function in anesthetized rats.

We have proposed that L-3,4-dihydroxyphenylalanine (L-DOPA) is a neurotransmitter in the central nervous system [Misu Y. et al. (1996) Prog. Neurobiol. 49, 415-454]. Herein, we attempt to clarify whether lesions in the posterior hypothalamic nucleus decrease the tissue content of L-DOPA in the rostral ventrolateral medulla. We also attempt to clarify whether or not endogenous L-DOPA is evoked by electrical stimulation of the posterior hypothalamic nucleus. It is possible that evoked L-DOPA functions as a transmitter candidate to activate pressor sites of the rostral ventrolateral medulla in anesthetized rats. Electrolytic lesions were made in the bilateral posterior hypothalamic nucleus by a monopolar direct current of 2 mA for 10 s, 10 days before measurements. The effect of the lesions was to selectively decrease the tissue content of L-DOPA by one-half in the right rostral ventrolateral medulla. Decreases in the amounts of dopamine, noradrenaline or adrenaline were not observed. Decreases were also not evident in the right caudal ventrolateral medulla. During microdialysis of the right rostral ventrolateral medulla, extracellular basal levels of L-DOPA and three types of catecholamine were consistently detectable by high-performance liquid chromatography with electrochemical detection. Tetrodotoxin (1 microM) perfused into the right rostral ventrolateral medulla gradually decreased basal levels of L-DOPA by 25%; it decreased basal levels of noradrenaline and adrenaline by 25-30% and dopamine levels by 40%. Intensive electrical stimulation of the ipsilateral posterior hypothalamic nucleus (50 Hz, 0.3 mA, 0.1 ms duration, twice for 5 min at an interval of 5 min) selectively caused the release of L-DOPA in a repetitive and constant manner. The stimulation was accompanied by hypertension and tachycardia. However, catecholamines were not released. Tetrodotoxin suppressed the release of L-DOPA, but partially inhibited hypertension with only a slight inhibition of tachycardia evoked by stimulation of the posterior hypothalamic nucleus. L-DOPA methyl ester, a competitive L-DOPA antagonist, was bilaterally microinjected into pressor sites of the rostral ventrolateral medulla at 1.5 microg x 2 and 3 microg x 2. The antagonist dose-dependently and consistently antagonized pressor and tachycardiac responses to mild transient stimulation of the unilateral posterior hypothalamic nucleus (33 Hz, 0.2 mA, 0.1 ms duration, for 10 s). In addition, the antagonist alone (3 microg x 2) elicited hypotension and bradycardia. These results show that an L-DOPAergic relay may project from the posterior hypothalamic nucleus directly to pressor sites of the rostral ventrolateral medulla and/or indirectly to certain neurons near pressor sites in microcircuits of the same region. When released, L-DOPA appears to function tonically to activate pressor sites; it also appears to be involved in the maintenance and regulation of blood pressure and heart rate.

Animals↗
PubMed1999

L-dopaergic components in the caudal ventrolateral medulla in baroreflex neurotransmission.

L-3,4-Dihydroxyphenylalanine (L-DOPA) is probably a transmitter of the primary baroreceptor afferents terminating in the nucleus tractus solitarii; L-DOPA functions tonically to activate depressor sites of the caudal ventrolateral medulla, which receives input from the nucleus tractus solitarii [Misu Y. et al. (1996) Prog. Neurobiol. 49, 415-454]. We have attempted to clarify whether or not L-DOPAergic components within the caudal ventrolateral medulla are involved in baroreflex neurotransmission in anesthetized rats. Electrolytic lesions of the right nucleus tractus solitarii (1 mA d.c. for 10 s, 10 days before measurement) selectively decreased by 45% the tissue content of L-DOPA in the dissected ipsilateral caudal ventrolateral medulla. Electrolytic lesions did not decrease dopamine, norepinephrine and epinephrine levels. During microdialysis of the right caudal ventrolateral medulla, extracellular levels of L-DOPA, norepinephrine, epinephrine and 3,4-dihydroxyphenylacetic acid were consistently detectable using high-performance liquid chromatography with electrochemical detection. However, extracellular dopamine levels were lower than the assay limit. Baroreceptor activation by i.v. phenylephrine selectively evoked L-DOPA without increasing the levels of norepinephrine, epinephrine and 3,4-dihydroxyphenylacetic acid. This L-DOPA release was suppressed by acute lesion in the ipsilateral nucleus tractus solitarii. Intermittent stimulation of the right aortic depressor nerve (20 Hz, 3 V, 0.3 ms duration, for 30 min) repetitively and constantly caused L-DOPA release, hypotension and bradycardia, without increases in levels of norepinephrine, epinephrine and 3,4-dihydroxyphenylacetic acid. Local inhibition of L-DOPA synthesis with alpha-methyl-p-tyrosine (30 microM) infused into the ipsilateral caudal ventrolateral medulla gradually decreased basal levels of L-DOPA and 3,4-dihydroxyphenylacetic acid without decreasing norepinephrine and epinephrine. The inhibition of L-DOPA synthesis interrupted L-DOPA release and decreased by 65% depressor responses elicited by aortic nerve stimulation; however, it produced no effect on bradycardic responses. CoCl2 (119 ng), a mainly presynaptic inhibitory transmission marker, and L-DOPA methyl ester (1 microg), a competitive L-DOPA antagonist, when microinjected into depressor sites of the right caudal ventrolateral medulla, reduced by 60% depressor responses to transient ipsilateral stimulation of the aortic nerve (20 Hz, 3 V, 0.1 ms duration, for 10 s). No changes in bradycardic responses were observed. There may exist an L-DOPAergic relay from the nucleus tractus solitarii to the caudal ventrolateral medulla. L-DOPAergic components in the caudal ventrolateral medulla are involved in baroreflex neurotransmission via a baroreceptor-aortic depressor nerve-nucleus tractus solitarii-caudal ventrolateral medulla relay in the rat.

Animals↗
PubMed1999

[Computed tomography with normal chest radiography in childhood tuberculosis].

During the recent 2 years we experienced 5 children (2 months-5 years old) with lung tuberculosis, all of whom had positive tuberculin skin-tests, and were in close contact with their family members who had active tuberculosis. However, no abnormal findings on chest X-ray films were pointed out by 2 independent roentogenologists, and no increased levels of inflammatory markers including WBC numbers, CRP, and ESR were detected in all but one child. Moreover, mycobacterial examination of sputa and/or gastric aspirates by microscope, culture technique, and PCR amplification revealed no causative bacilli in 4 children. To clarify whether these children were affected by Mycobacterium tuberculosis, chest CT scan was applied. Surprisingly, all 5 children were revealed to have abnormal changes including primary complexes in the lung field. Taken together, it is important to pursuit the apparent lung tuberculosis in children with a positive family history and positive tuberculin skin-test.

Child↗
PubMed1999

[Analysis of tuberculin reaction of tuberculous children below 4 years of age].

To clarify whether the size of tuberculin reaction could be used as an useful index of the severity of tuberculosis, we analyzed the sizes of tuberculin reaction (TR) of 60 children below 4 years of age with active tuberculosis at the time of diagnosis. Of 60 patients, 53 (88.9%) had positive reactions to tuberculin. The mean size of TR of 60 patients was 24.0 +/- 13.9 mm and maximum size was 60 mm. Seven patients who had no reaction to the tuberculin skin test consisted of three primary complex and four serious tuberculosis (two miliary tuberculosis and two tuberculous meningitis). The patients without BCG vaccination showed significantly smaller TR than the patients with BCG vaccination (p < 0.05). The patients less than 1 year of age showed significantly smaller TR than the patients of 4 years of age (p < 0.05). The patients with serious tuberculosis showed significantly smaller TR than the patients with primary complex (p < 0.05). Of patients with primary complex, there were no difference of the size of TR between the patients with pulmonary tuberculosis (III) and hilar lymphadenopathy (H). Together with, it did not necessarily mean that negative TR showed no infection with tuberculosis and the sizes of TR depended on the severity of tuberculosis in infantis and young children.

Child, Preschool↗
PubMed1999

Molecular epidemiological study of Haemophilus influenzae serotype b strains obtained from children with meningitis in Japan.

We report an epidemiological study of 30 Haemophilus influenzae serotype b (Hib) strains derived from the cerebrospinal fluid of children with meningitis. The Hib strains were biotyped, tested for beta-lactamase production, and genotyped by long PCR-ribotyping, random amplified polymorphic DNA (RAPD) analysis, and genomic DNA restriction fragment length polymorphism (RFLP) analysis by pulsed-field gel electrophoresis (PFGE). The phenotypic study characterized 22 of the strains (73%) as biotype I. A genotypic study using long PCR-ribotyping with HaeIII restriction digestion showed no polymorphisms among these 30 Hib strains, but RAPD analysis with two sets of primers demonstrated two distinctive subtypes: one typical of the strains of biotype group II and the second characteristic of the strains of biotype groups I and IV. Each RAPD group was subtyped into several genotypic groups by PFGE-RFLP with SmaI digestion. The genotyping of clinically isolated Hib strains may help to elucidate transmission routes in community infections, endemicity, and the reasons for vaccine failure.

Child, Preschool↗
PubMed1999

[A DOPA antagonist, DOPA cyclohexyl ester inhibits transient brain ischemia-induced release of glutamate and delayed neuronal cell death in striatal and hippocampal region of in vivo rats].

We have previously obtained evidence that DOPA is probably involved in an upstream process of mechanisms for in vivo neuronal cell death in striatum. We attempted to clarify whether or not this is also the case in hippocampal region of conscious Wistar rats. Four vessels were occluded for 5 min during microdialysis of hippocampus. DOPA, dopamine and glutamate (Glu) in perfusates collected every 10 min were measured by HPLC-ECD and spectrophotometer. Delayed neuronal cell death in hippocampus was evaluated 96 hr after ischemia. Five-min transient brain ischemia induced Glu release, with the peak being 2.5-fold of a basal release at the fraction immediately after ischemia. The release of DOPA and dopamine was not consistently detectable, but an increase was sometimes observed during and after ischemia. Delayed neuronal cell death was slight to moderate with 5-min ischemia. Intrastriatal perfusion of DOPA cyclohexyl ester (DOPA CHE) at 100 nM, a novel stable potent competitive DOPA antagonist, almost completely inhibited the ischemia-induced glutamate release, and protected hippocampal neurons from delayed cell death. Endogenously released DOPA itself seems to act on its recognition site and to behave as a causal and/or deteriorating factor on glutamate release and resultant delayed neuronal cell death by transient ischemia in rats.

Animals↗
PubMed1999

Selection of the most efficacious of twenty-two inactivated Sendai virus nasal vaccines by determination of the protection index in mice.

BACKGROUND AND PURPOSE: Sendai virus nasal vaccines inactivated with various chemicals induce complete protection against contact-challenge exposure with the Nagoya strain. The study reported here was to reevaluate the efficacy of the inactivants by determining the protective index (PI) in mice, using the more virulent MN strain. METHODS: Mice were given each of 22 inactivated vaccines intranasally three times. After challenge exposure with 10(-2) to 10(6) MID50 of virus, infection of cells of the respiratory tract was determined by immunofluorescence. RESULTS: Twelve vaccines induced PI > or = 2.0 in the nasal mucosa and were classified as group 1. The first half of the preceding vaccines that induced PI > or = 3.2 in the larynx were classified subgroup a, and the rest were classified subgroup b. Of the other 10 vaccines, 6 that induced PI < or = 2.0 in the larynx and 4 that induced intermediate PI in the nasal mucosa and larynx were ranked as groups 3 and 2, respectively; PI of the trachea decreased by numeric order of groups. Serum hemagglutination inhibition titer induced by intranasal vaccination was low in general. CONCLUSION: On the basis of PI values, 6 of the 22 nasal vaccines provided the strongest defense in the respiratory tract.

Administration, Intranasal↗
PubMed1999

[Effective combination therapy of plasma exchange and subsequent cyclophosphamide pulses for catastrophic antiphospholipid antibody syndrome: a case report].

A 7-year-old girl with catastrophic antiphospholipid antibody syndrome was described. She firstly admitted to the local hospital with the complaints of persistent fever and abdominal pain, and was diagnosed as systemic lupus erythematosus with the laboratory findings as follows; positive for antinuclear antibody, anti-DNA antibody, and platelet-associated IgG, thrombocytopenia, and hypocomplementemia. 10 days after the initiation of oral prednisolone, she suddenly manifested tonic convulsion and unconsciousness accompanied by high fever. Because of the unresponsiveness to the methylprednisolone pulse therapy for supposed CNS lupus, she was transferred to our hospital. Her unconsciousness persisted, and pulsation on dorsalis pedis was not palpable on admission. Laboratory investigation revealed the falsely positive VDRL, a prolonged aPTT, positive for lupus-anticoagulant and antiphospholipid antibody. The magnetic resonance image demonstrated multiple spotty hyperintensity (T2) in the brain consistent with multiple hemorrhagic infarcts. Arteriogram demonstrated the infarct of dorsalis pedis, and coronary aneurysms. These findings were compatible with the criteria of catastrophic antiphospholipid antibody syndrome, she was diagnosed as catastrophic antiphospholipid antibody syndrome. The plasma exchange and subsequent cyclophosphamide-pulse therapy, which was given once a month for first 6 months, and later, at 3 months intervals, was effectively administered. This combination and oral anti-thrombotic therapy revealed effective for this kind of fatal disorder.

Anticoagulants↗
PubMed1999

[An infant of autoimmune hepatitis (type I) with cirrhosis].

A 6 year-old boy with autoimmune hepatitis accompanied with cirrhosis was reported. He was admitted to our hospital because of abdominal distention, high fever, and diarrhea. Laboratory examination revealed abnormalities in hepatic function, cholestasis, anemia, thrombocytopenia, hypoalbuminemia, hypocomplementemia, and low concentration of coagulation factors. Abdominal MRI, and asialoglycoprotein receptor-mediated liver scintigraphy strongly indicated liver cirrhosis. Viral hepatitis, Wilson's disease, and antitrypsin deficiency were excluded serologically. Instead, hypergammaglobulinemia, and positive antinuclear antibody suggested autoimmune hepatitis, and the survey of anti-mitochondrial antibody, anti-smooth muscle antibody, and anti-LKM-1 antibody was negative, indicating type I autoimmune hepatitis. Finally, the histology of liver biopsy specimen indicating the destruction of hepatic lobular architecture, dense mononuclear cell infiltrates, and severe fibrosis confirmed the diagnosis. He was treated firstly with methylprednisolone pulses, and then prednisolone p.o. + azathioprine p.o. All of the abnormal laboratory parameters improved to normal levels, indicating that the immunosuppressive therapy will be effective for the severe AIH with cirrhosis.

Child↗
PubMed1999

[Improvement of the maintenance therapy after methylprednisolone pulse therapy--effect of prednisolone combined with immunosuppressants].

OBJECTIVES: We investigated the effect of the combination therapy of prednisolone (PSL) and immunosuppressants after methylprednisolone pulse therapy. METHODS: A protocol of PSL (15-20 mg/day) and mizoribine (150-200 mg/day) after methylprednisolone (mPSL) pulses was used for 2 years to treat 7 patients (PSL + MZB group). Cyclophosphamide (CYC) pulse therapy was added to the combined therapy in 4 patients with severe lupus nephritis. The total dose of predinisolone, and side effects were compared with those in 6 patients who were treated with PSL (30 mg/kg) alone after mPSL pulse therapy (PSL group). RESULTS: No relapses occurred in the PSL + MZB group, although all of 6 patients relapsed in the PSL Group. The total doses of PSL in the PSL + MZB group was about 70% of the PSL Group. There were two patients with Herpes-Zoster infection and one patient with liver dysfunction as side effects, with no differences in the frequency of side effects between the was groups. CONCLUSIONS: Combination maintenance therapy with prednisolone and immunosuppressants after methylprednisolone pulse therapy was effective in preventing relapse.

Adolescent↗
PubMed1998

Angle-resolved UV photoelectron spectra (UPS) of thin films of perylene-3,4,9,10-tetracarboxylic dianhydride on MoS(2).

Angle-resolved UV photoelectron spectra (ARUPS) were measured for thin films of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) deposited on cleaved MoS(2) surfaces. The take-off angle (theta) dependence of the photoelectron intensity of the highest pi band showed a sharp maximum at theta = 32-34 degrees. A spectral feature of the binding energy at approximately 8.9 eV, which is believed to originate from a pi state, showed a remarkably different theta dependence from that of the pi band. A quantitative analysis of the observed theta dependencies clearly indicates that (a) the feature at approximately 8.9 eV originates from the oxygen 2p non-bonding states and (b) the molecules lie flat on the substrate surface.

Journal Article↗
PubMed1998

Temperature dependence of photoelectron angular distribution from thin films of chloroaluminum phthalocyanine on MoS(2).

Angle-resolved UV photoelectron spectra were measured for thin films of chloroaluminum phthalocyanine deposited on cleaved MoS(2) surfaces. The take-off angle (theta) dependence of the photoelectron intensity of the highest pi band showed a remarkable sharpening upon cooling the film, indicating that thermal excitation of molecular vibrations gives a considerable broadening of the photoelectron angular distribution. The theta dependence observed at approximately 120 K agrees well with that calculated.

Journal Article↗
PubMed1998

[Is endogenously released DOPA itself an upstream factor for increase in glutamate release and delayed neuronal cell death induced by transient ischemia in rats?].

DOPA itself is a neuromodulator in striata. In rat striata, DOPA by itself released neuronal glutamate in slices and caused cell death via glutamate release in cultured fetal neurons, suggesting involvement of DOPA in an upstream process of mechanisms for in vivo neuronal cell death. We attempted to clarify whether or not this idea is truly the case in conscious Wistar rats. Four vessels were occluded for 10 min during microdialysis of striata. DOPA, dopamine and glutamate in perfusates collected every 10 min were measured by HPLC-ECD and spectrophotometer. Delayed neuronal cell death in striata and hippocampus was evaluated 96 hr after ischemia. DOPA was indeed evoked with dopamine and glutamate during and after ischemia, and peak increases by respective 6-, 210- and 8-fold of a basal level were seen at the fraction immediately after ischemia. Delayed neuronal cell death was slight to moderate in striata and severe in hippocampus. Intrastriatal perfusion of NSD-1015, a central DOPA decarboxylase inhibitor, at 30 microM 10 min before ischemia, markedly increased DOPA and glutamate release by ischemia with slight inhibition of dopamine release and exaggerated delayed neuronal cell death in striata. Meanwhile, intrastriatal perfusion of DOPA cyclohexyl ester (DOPA CHE) at 10-100 nM, a novel stable potent competitive DOPA antagonist, antagonized dose-dependently increases in glutamate release by ischemia without modification of dopamine release. DOPA CHE at 100 nM protected striatal neurons from delayed cell death. Hippocampal neuronal cell death was neither affected by NSD-1015 nor by DOPA CHE. Endogenously released DOPA itself seems to act on its recognition site and to be a causal factor for increase in glutamate release and resultant delayed neuronal cell death by transient ischemia in rats.

Animals↗
PubMed1998

[Clinical analysis of 11 cases of juvenile dermatomyositis and polymyositis].

Juvenile dermatomyositis (JDM) is characterized by microvasculopathy of the striated muscle, which indicates different etiology, clinical manifestation and prognosis from the adult-onset dermatomyositis. We experienced 10 cases of JDM and 1 case of juvenile polymyositis (JPM) in the recent 14 years, and analyzed clinical manifestation, laboratory findings, treatment anrognosis. The cases were 9 girls and 2 boys. The onset of the disease was 2 years of age in 2 patients, and 9 to 13 years of age in 9 patients. During the follow-up courses, no cases were dead or complicated with neoplasm. Skin rash was the most frequent manifestation at the onset, and facial erythema was common. Muscle weakness was observed only in 4 cases at the onset, and in all cases muscle enzymes including creatine kinase and aldolase were elevated. The clinical course was classified into three groups; monocyclic (5 cases), chronic and recurrent (4 cases), and fulminant (2 cases). Prognosis depended not on the degree of the elevated serum muscle enzymes, but on the initial therapy employed at the onset of the disease. Five cases including 2 cases of fulminant type were initially treated with methylprednisolon pulse therapy, and all of these had no recurrence. On the other hand, 6 cases were started the therapy with p.o. prednisolone. Four of them had frequent recurrences in accordance with tapering of prednisolone. These cases were effectively treated with the combination with immunosuppressants. In previous reports, JDM and JPM were reported to be a disorder which had relatively favorable prognosis. But we found that one third of the cases had chronic and recurrent courses. Methylprednisolone pulses as initial therapy may be effective in preventing the chronicity and recurrence of the disease.

Adolescent↗
PubMed1997

An L-DOPA-like depressor action of L-threo-dihydroxyphenyl-serine in the rat caudal ventrolateral medulla.

We have proposed that L-3,4-dihydroxyphenylalanine (L-DOPA) is a neurotransmitter and/or neuromodulator in the central nervous system (1). In this study, we investigated whether or not L-threo-dihydroxyphenylserine (L-threo-DOPS), a synthetic amino acid structurally related to L-DOPA, microinjected into the caudal ventrolateral medulla (CVLM) and the rostral ventrolateral medulla (RVLM) shows cardiovascular actions similar to those of L-DOPA in anesthetized rats. When L-threo-DOPS was microinjected into CVLM, it produced dose-dependent (0.01-3 ng) depressor and bradycardic responses. D-threo-DOPS (3 ng) produced no effect. The responses to L-threo-DOPS (1 ng) were almost completely blocked by L-DOPA methyl ester (1 microg), a competitive antagonist for L-DOPA, supporting the existence of an L-threo-DOPS-sensitive recognition site for L-DOPA in CVLM. Microinjection of L-threo-DOPS into RVLM, however, showed no effect (0.001-100 ng), which contrasted with the cardiopressor action of L-DOPA applied in RVLM. In RVLM, there may exist an L-threo-DOPS-insensitive recognition site for L-DOPA.

Animals↗
PubMed1997

[Studies on novel, stable and potent competitive antagonists against L-DOPA].

DOPA has been proposed to be a neurotransmitter of the primary baroreceptor afferents terminating in the NTS and a neuromodulator in striata of rats. Pre- and post-synaptic recognition sites for DOPA itself may exist. DOPA methyl ester (DOPA ester), a potent competitive antagonist for DOPA in continuously superfused slices or within a several min when microinjected in the NTS has some limitation in in vivo use because of its unstableness as a prodrug for DOPA. We have explored to find stable and potent antagonists for DOPA. At first, we tried to clarify whether or not newly synthesized DOPA esters with bulky structure such as DOPA cyclohexyl ester (CHE), DOPA cyclopentyl ester (CPE) and DOPA cyclopentyldimethyl ester (CPDME) antagonize depressor responses to DOPA microinjected into the NTS, and to what degree these analogues 1 microM perfused via probes are converted to DOPA during striatal microdialysis in urethane-anesthetized rats. Then, we analyzed mode of antagonism of some candidate in the NTS system. During striatal microdialysis, DOPA ester 1 microM increased extracellular levels of DOPA to an 100 fold higher level at a peak of the 1st 20 min sample after the perfusion. Conversion ratio of CHE, CPE and CPDME, compared to DOPA ester, was less than 1/5 at the peak of the 3rd sample, 1/3.3 at the peak of the 2nd, and 1/2.7 at the peak of the 3rd, respectively. In the NTS, all analogues 1 microgram microinjected abolished depressor responses to DOPA 60 ng. Time required to recover a base was 20 min for CHE and 10 min for DOPA ester, CPE and CPDME. At 100 ng, CHE inhibited peak depressor responses to DOPA 60 ng by 53%, CPE by 40%, and CPDME by 24%, compared to DOPA ester by 22%. Then, DOPA 10-300 ng microinjected produced dose-dependent hypotension. DOPA ester 300 ng, microinjected 1 min previously, shifted a dose-response curve for DOPA 30-300 ng to the right without reduction of the maximum response, showing a competitive mode of antagonism. CHE 30 ng competitively antagonized depressor responses to DOPA 18-300 ng without reduction of the maximum response. CHE 100 ng further shifted the dose-response curve for DOPA 18-100 ng to the right with 25% reduction of the maximum response. Antagonistic activity of CHE 100 ng was equipotent with DOPA ester 300 ng. CHE is a competitive antagonist including partially some noncompetitive components. A possible component might be related to NMDA receptors, since high concentrations of CHE displaced selective binding of [3H]-MK-801, an antagonist. In conclusion, CHE is suitable for the purpose.

Animals↗
PubMed1997

Antithrombotic effects of the novel inhibitor of thrombin-induced offtelet aggregation and thrombus formation, 3-[2-[1,1':2',1"]-terphenyl-4'-yl)ethyl]phenoxyacetic acid.

The new compound 3-[2-([1,1':2,1"]-terphenyl-4'yl)ethyl]phenoxyacetic acid (F1070) was synthesized and its effects on platelet aggregation induced by thrombin, thrombin receptor agonist peptide (TRAP), ADP and collagen were evaluated in humans, guinea pigs and rats, and were compared with the effects of he thrombin antagonists argipidine and (D)Phe-Pro-Arg-CH2Cl (FPR). F1070 inhibited the platelet aggregation induced by these agonists and was highly selective in its inhibition of thrombin. F1070 inhibited fibrin formation induced by thrombin, but far less effectively than argipidine. In a guinea pig model of extracorporeal circulation thrombosis, F1070 (10 mg/kg p.o.) significantly inhibited the development of a thrombus. F1070 is thus a key compound that should facilitate the development of new orally active antithrombotic drugs that are specific for thrombin.

Animals↗