Nucleotide and derived amino acid sequence of a catalase cDNA isolated from rice immature seeds.
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Amino Acid Sequence↗
Biomedical subjects
K Higo
Publications and source records attributed to K Higo.
Protective effects of benidipine hydrochloride (KW-3049), a calcium antagonist, against experimental arterial calcinosis and endothelial dysfunction in rats.
Protective effects of benidipine hydrochloride (KW-3049) against arterial calcinosis and its possible mechanisms of action have been investigated. Arterial calcinosis was induced in rats by combined administration of vitamin D2 (1050000 IU/kg, s.c.) and nicotine (12.5 mg/kg, p.o., b.i.d.) for 6 successive days. Calcium antagonists, benidipine or nifedipine, were given orally twice a day during the same period. The aortic calcium content in vitamin D2 and nicotine-treated (control) rats increased to about 25 times that in normal rats, accompanying an increase of serum calcium level. Benidipine (10 mg/kg, p.o., b.i.d.) reduced the aortic calcium content to about 18% of control rats without reducing the serum calcium level. Although the presence of aortic endothelial cells was observed under light microscopy in control rats, their surfaces were degenerated under scanning electron microscopy. Benidipine exerted a protective effect against these degenerative changes. Acetylcholine-induced endothelial dependent relaxation was attenuated in control rats, compared with that in normal rats. Benidipine significantly improved this attenuation of the relaxation. These results suggest that the anticalcinotic effect of benidipine is accompanied by its protective effect on endothelial cells.
Acetylcholine↗
Early thrombolysis by recombinant tissue-plasminogen activator is beneficial to the ischemic myocardium.
We examined the effect of coronary thrombolysis by recombinant tissue-plasminogen activator (rtPA) on infarct size using a thrombin-induced thrombosis model of open-chest anesthetized dog. Occlusive thrombus was induced by injection of thrombin (100 U) in the left anterior descending coronary artery (LAD). The intravenous infusion of rtPA (10 micrograms/kg/min) was started at 30 min (30 min-ischemia group) or at 60 min (60 min-ischemia group) after the formation of thrombus, and was continued for 30 min. Spontaneous thrombolysis was not observed in the 360 min-ischemia (vehicle-treated) group. Intravenous infusion of rtPA elicited thrombolysis within 30 min in all the dogs except in one in the 60 min-ischemia group. The infarct size was significantly reduced by rtPA-induced thrombolysis. The shorter the duration of the ischemia, the longer the effect of the drug, and the infarct size after thrombolysis was smaller in the 30 min-ischemia group than in the 60 min-ischemia group. Ischemia-induced changes in ST-segment of electrocardiogram (ECG) were significantly ameliorated after thrombolysis in both 60 min- and 30 min-ischemia group. These results suggest that early reperfusion of coronary thrombosis by rtPA is beneficial to the ischemic myocardium.
Anesthesia↗
Actions of the novel thromboxane A2 receptor antagonist sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)-ethylidene]-6,11- dihydrodibenz[b,e]oxepine-1-carboxylate monohydrate on smooth muscle preparations.
The effects of KW-3635 (sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)- ethylidene]-6,11-dihydrodibenz[b,e]oxepine-2-carboxylate monohydrate, CAS 127166-41-0) on smooth muscle preparations were examined. In isolated guinea-pig aorta, KW-3635 competitively inhibited the U-46619 (a thromboxane mimetic) induced contractions (pA2 = 7.74), the effect being more potent than those of sulotroban and daltroban. In canine saphenous vein, KW-3635 also antagonized the U-46619-induced contraction (pA2 = 8.11). In this preparation, solutroban and daltroban, but not KW-3635, exhibited intrinsic agonistic action. KW-3635, even at a high concentration of 10(-5) mol/l did not affect the norepinephrine- or KCl-induced contractions of guinea-pig or rat aorta, prostaglandin (PG)E2- or PGF2 alpha-induced contractions of guinea-pig ileum nor the PGE2-induced contraction of rat fundus. KW-3635 at concentrations higher than its thromboxane A2- (TxA2-)antagonistic one, non-competitively inhibited the PGF2 alpha-induced contractions of guinea-pig aorta (pD2' = 6.23), as was the case with daltroban. The inhibitory effect of KW-3635 (3 x 10(-6) mol/l) on U-46619-induced contractions of guinea-pig aorta persisted for longer than 2 h following washout of the tissue, whereas that of daltroban (10(-5) mol/l completely disappeared at 1 h after the washout. In anesthetized guinea-pigs, KW-3635 at doses of 10 to 1000 micrograms/kg (i.v.) inhibited U-46619 (1 microgram/kg i.v.)-induced pressor responses in a dose-dependent manner. The effect of KW-3635 (0.1 to 1 mg/kg i.v.) persisted for longer than 3 h. These results demonstrate that KW-3635 is a potent and specific TxA2 antagonist without agonistic action in vascular smooth muscles. KW-3635 is considered to be a promising candidate for the treatment of patients with disorders mediated via TxA2.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
Enhancement of tissue-type plasminogen activator-induced thrombolysis and prevention of reocclusion by sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)- ethylidene]-6,11-dihydrodibenz[b,e]oxepine-2-carboxylate monohydrate in a canine model of femoral thrombosis.
The purpose of this study was to examine whether the blockade of thromboxane A2 (TxA2)/prostaglandin H2 (PGH2) receptor by the selective TxA2/PGH2 receptor antagonist KW-3635 (sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)ethylidene]-6,11- dihydrodibenz[b,e]oxepine-2-carboxylate monohydrate, CAS 127166-41-0) is effective in enhancing tissue-type plasminogen activator (tPA)-induced thrombolysis and preventing reocclusion in a model of femoral artery thrombosis in anesthetized dogs. The thrombus was formed by inserting a copper coil into the femoral artery. Sodium heparin (100 U/kg i.v.) was administered shortly after the formation of thrombus. All dogs received i.v. tPA at a dose of 20 micrograms/kg/min starting 60 min after the formation of the occlusive thrombus for up to 60 min if necessary, to achieve reperfusion. After 30 min of thrombotic occlusion, the animals received vehicle (Group I, controls, n = 9) or KW-3635 (Group II, 0.3 mg/kg bolus i.v. + 0.3 mg/kg/h infusion, n = 9; Group III, 1 mg/kg bolus i.v. + 1 mg/kg/h infusion, n = 9) and the infusion of either vehicle or KW-3635 was continued thereafter throughout the experiment. The time to reperfusion in Group I was 37.3 +/- 5.2 min, while those in Group II and Group III were 25.3 +/- 6.2 min (p greater than 0.05) and 17.3 +/- 3.1 min (p less than 0.05), respectively. Reocclusion occurred within 4 h in 100% of Group I, whereas the incidence of reocclusion was reduced to 67% in Group II and to 0% in Group III. These data suggest that endogenous TxA2 generation is involved in lysis and rethrombosis during thrombolytic therapy by tPA.(ABSTRACT TRUNCATED AT 250 WORDS)
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
Antiplatelet effects of the novel thromboxane A2 receptor antagonist sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)-ethylidene]-6,11- dihydrodibenz[b,e] oxepine-2-carboxylate monohydrate.
The effects of KW-3635 (sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)- ethylidene]-6,11-dihydrodibenz[b,e] oxepine-2-carboxylate monohydrate, CAS 127166-41-0) on platelet aggregation were examined. In human washed platelets, KW-3635 shifted the concentration-aggregation curves for U-46619, a thromboxane A2 (TxA2) mimetic, to the right. The pA2 value for KW-3635 was 8.8 +/- 0.10, while those for sulotroban and daltroban were 6.31 +/- 0.18 and 7.75 +/- 0.07, respectively. In human platelet rich plasma (PRP), KW-3635 at 10(-8) mol/l to 10(-6) mol/l inhibited the aggregations induced by U-46619 (1 mumol/l) or collagen (1.5 micrograms/ml). However, KW-3635 at up to 10(-5) mol/l did not affect the primary phase of platelet aggregation induced by adenosine diphosphate or epinephrine. KW-3635 at 10(-5) mol/l did not affect the antiaggregatory effects of the prostaglandins PGI2, PGE1 and PGD2. These results indicate that KW-3635 is a potent and selective TxA2 receptor antagonist. The TxA2 antagonistic effects of KW-3635 were compared with that of daltroban in PRP from various animals species. The effects of KW-3635 on platelet aggregation were species-dependent and KW-3635 exhibited the most prominent activity in human platelets. The activities of KW-3635 in mouse and rabbit PRP were much less potent. In PRP from guinea-pigs, dogs, cats and rats, KW-3635 exhibited moderate anti-aggregatory effects. In the guinea-pig PRP, KW-3635 at 10(-7) mol/l to 3 x 10(-6) mol/l inhibited both the platelet aggregation and the concomitant adenosine triphosphate secretion in a concentration-dependent manner, the effect being more potent than those of sulotroban and daltroban. In the experiments on the platelet aggregation ex vivo in guinea-pigs, KW-3635 at oral doses of 3 and 10 mg/kg inhibited the aggregations induced by U-46619 (1, 3 mumol/l), collagen (3, 6, 9 micrograms/ml) and arachidonate (50, 100 mumol/l). The effects lasted for longer than 7 h following oral administration. These results indicate that KW-3635 is a specific and orally active TxA2 receptor antagonist. KW-3635 is expected to be a drug useful for the treatment of patients with thrombotic disorders.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
Elevated expression of proto-oncogenes accompany enhanced induction of heat-shock genes after exposure of rat embryos in utero to ionizing irradiation.
We have recently found that the effects of exposing rat embryos in utero to teratogens capable of producing cardiac anomalies were expressed later as enhanced induction of heat-shock proteins (hsp70 family) when embryonic hearts were cultured in vitro. However, it remained to be determined whether heat-shock proteins are induced in vivo after exposure to teratogens. The heat-shock response in some mammalian systems is known to be accompanied by elevated expression of proto-oncogenes. Using gene-specific DNA probes, we examined the levels of the expression (transcription) of heat-shock protein genes and two nuclear proto-oncogenes, c-fos and c-myc, in the embryos removed from irradiated pregnant mother rats 4 or 5 days after the irradiation. We found that the levels of expression in vivo of the hsp70 and c-myc genes in the irradiated embryos increased by approximately twofold as compared with those in the control. The expression in vivo of the c-fos gene was not detected in either the irradiated or non-irradiated embryos. After 0.5-hr incubation in vitro of the embryos, however, the expression of the c-fos gene in the irradiated embryos was highly enhanced whereas the control showed no changes. Although the exact functions of these gene products still remain obscure, the enhanced expression of hsp70 gene(s) and the nuclear proto-oncogenes observed in the present study may reflect repair of intracellular damages and/or regeneration of tissue by compensatory cell proliferation, processes that may disturb the normal program of organogenesis.
Animals↗
Effects of gamma-ray irradiation in utero on developing hearts of rat embryos: inhibition of accumulation of a 27-kDa protein.
Rat embryos were irradiated in utero with 1.5-Gy (teratogenic dose) of 60Co gamma-rays on Day 9 of gestation, and the protein composition of each embryonic heart was examined by two-dimensional electrophoresis on Day 18. Almost all of about 450 protein species detected were identical to those of the non-irradiated hearts. However, a 27-kDa protein was reproducibly found in decreased amount in the irradiated samples. In the normal development of the heart, this protein accumulates rapidly either during the last several days of gestation or upon birth. Therefore, the irradiation with gamma-rays inhibited the accumulation of this protein.
Animals↗
Effects of exposing rat embryos in utero to physical or chemical teratogens are expressed later as enhanced induction of heat-shock proteins when embryonic hearts are cultured in vitro.
In order to get more insight into the effects of teratogens on developing embryos, we investigated the protein synthesis patterns of the target organs isolated from teratogen-treated embryos. Rat embryos were either irradiated in utero with either 252Cf fission neutrons or 60Co gamma rays on day 8 of gestation or treated in utero with a bis(dichloroacetyl)diamine (a chemical teratogen) on days 9 and 10. Hearts were removed from the embryos on day 12 and were incubated in vitro at 37 degrees C in the presence of [35S]methionine for up to 8 hr. The newly synthesized labeled proteins were then analyzed qualitatively by two-dimensional polyacrylamide gel electrophoresis. Enhanced and prolonged induction of a family of heat-shock (stress) proteins with a molecular weight of about 70,000 (SP70s) was observed as compared with those of controls. Among the teratogen-treated hearts, those with gross malformations already detectable at this early stage showed especially higher inductions of SP70s than did the others. The abnormal expression of SP70s observed in the present study appears to be a reflection of persisting cellular (tissue) damage inflicted by the teratogens, and the extent of the induction may be indicative of the degree and/or type of the damage. Such persisting defects in surviving cells, manifested by abnormal induction of SP70s in the present study, might be related to malformation of embryonic hearts.
Animals↗
Characteristics of [3H]nimodipine binding to sarcolemmal membranes from rat vas deferens and its regulation by guanine nucleotide.
The binding properties of a 1,4-dihydropyridine (DHP) calcium entry blocker, [3H]nimodipine, to a microsomal fraction from rat vas deferens was characterized. The specific binding was saturable, rapid and reversible. Scatchard analysis of the binding revealed a single binding site, and the dissociation constant and the maximum number of binding sites were 0.31 +/- 0.02 nM and 97.0 +/- 7.19 fmol/mg protein, respectively. Both the Kd value obtained from the kinetic study and the IC50 value from relaxation of the K+-depolarized organ were approximately 0.4 nM, indicating that the binding site is closely related to the functional Ca2+ channel. The specific [3H]nimodipine binding was displaced by DHP derivatives at low concentration and by verapamil at high concentration, but diltiazem had no effect on the binding. Calcium chelating agents decreased the [3H]nimodipine binding which was restored by adding Ca2+. 5'-Guanylylimidodiphosphate caused a rightward shift of the displacement curve for Bay K 8644 but not for nimodipine, suggesting the involvement of guanine nucleotide binding protein in the signal transduction between the DHP binding site and the Ca2+ channel.
Animals↗
[Radiological study on early gastric cancer in the cardia].
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Adult↗
Induction of an hsp70-like protein during organ culture of rat embryonic heart.
Hearts were isolated from rat embryos on Day 12 of gestation and incubated in vitro at 37 degrees C in the presence of [35S]methionine; the labeled proteins were then analyzed by two-dimensional gel electrophoresis. The results showed that an acute and transient synthesis of an hsp70 (heat-shock proteins with a M.W. of about 70,000)-like protein was induced in the isolated rat embryonic hearts, without the concomitant total inhibition of normal cellular protein synthesis usually observed in other heat-shock systems. The significance of the results to the embryonic stress hypothesis of teratogenesis recently proposed is discussed.
Animals↗
Specificity of ionizing radiation-induced mutagenesis in the lac region of single-stranded phage M13 mp10 DNA.
M13 mp10 single-stranded phage DNA was irradiated with 60 Co gamma-rays, and transfected into Escherichia coli. One hundred and sixteen mutant clones having lesions in the lac insert were selected, and mutational sites were examined by DNA sequence analysis. Fourteen out of the 15 nucleotide changes thus detected were base substitutions, and the rest was a base addition. Transitions and transversions were almost equal in number. Mutational events were observed at cytosine residues more frequently than at other residues, and the predominant base change was a C ---- T transition. Possible roles in gamma-ray-induced mutagenesis played by the misincorporation of dAMP owing to radiolytic derivatives of cytosine residues and/or formation of apurinic/apyrimidinic sites are discussed.
Base Sequence↗
Effect of tritiated water on growth of a radiation-sensitive strain of Escherichia coli, NG30.
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Dose-Response Relationship, Radiation↗
Yeast ribosomal proteins: VII. Cytoplasmic ribosomal proteins from Schizosaccharomyces pombe.
The cytoplasmic ribosomal proteins from a fission yeast Schizosaccharomyces pombe were analysed by two-dimensional polyacrylamide gel electrophoresis. Seventy-three protein species were identified in the 80S ribosome, and named SP-S1 to SP-S33 and SP-L1 to SP-L40 in the small and large subunits, respectively. Many of these proteins could be correlated to those of Saccharomyces cerevisiae on the basis of their electrophoretic mobilities. Eleven proteins were isolated from the 80S ribosome, and their amino acid compositions were determined. Of these, SP-S6, SP-L1, SP-L12, SP-L15, SP-L17, SP-L27, SP-L36 and SP-L40c and d were sequenced from their amino-termini. SP-S28 and SP-L2 appear to have their amino-termini blocked. These results were compared with the data available for the S. cerevisiae and rat liver ribosomal proteins. The S. cerevisiae counterparts of the eight proteins mentioned above were found to be YS4, YL1, YL10, YL14, YL35, YL40 and YL44c and d, respectively. The rat liver counterparts of SP-S6, SP-L1, SP-L27 and SP-L40c and d were the rat S6, L4, L37 and P2, respectively. Comparison of the partial sequences of these ribosomal proteins suggests that these two yeasts are relatively far apart, phylogenetically.
Amino Acid Sequence↗
Isolation of seventeen proteins and amino-terminal amino acid sequences of eight proteins from cytoplasmic ribosomes of yeast.
Seventeen ribosomal proteins of Saccharomyces cerevisiae were isolated from small ribosomal subunits and disodium ethylenediaminetetraacetate treated 80S ribosomes by chromatography on a column of carboxymethylcellulose and/or by filtration through Sephacryl S-200. The isolated proteins are YS4, YS7, YS8, YS9, YS10, YS12, YS14, YS18, YS23, YS29, YL11, YL13, YL16, YL17, YL22, YL38, and YL40 [nomenclature according to Otaka & Osawa (1981) [Otaka, E., & Osawa, S. (1981) Mol. Gen. Genet. 181, 176-182]]. The purification procedures and the amino acid compositions of these proteins are presented. Amino-terminal amino acid sequences of YS4, YS6, YS11, YS15, YS16, YS22, YL10, and YL31 have been determined and compared with those from rat liver [Wittmann-Liebold, B., Geissler, A. W., Lin, A., & Wool, I. G. (1979) J. Supramol. Struct. 12, 425-433] and Halobacterium cutirubrum [Matheson, A. T., Möller, W., Amons, R., & Yaguchi, M. (1980) in Ribosomes: Structure, Function and Genetics (Chambliss, G., et al., Eds.) pp 297-332, University Park Press, Baltimore, MD; M. Yaguchi, unpublished experiments].
Amino Acid Sequence↗
Alteration of ribosomal protein S5 from two spectinomycin-resistant mutants of Bacillus subtilis: deletion of one amino acid residue.
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Amino Acid Sequence↗
Purification and characterization of 30S ribosomal proteins from Bacillus subtilis: correlation to Escherichia coli 30S proteins.
Twenty proteins were isolated from the 30S ribosomal subunits of Bacillus subtilis and their amino acid compositions and amino-terminal amino acid sequences were determined. These results were compared with the data of Escherichia coli 30S ribosomal proteins and the structural correspondence of individual ribosomal proteins has been established between B. subtilis and E. coli. Post-translational modifications of amino-terminal amino acids of the ribosomal proteins which have been found in E. coli are almost absent in B. subtilis with the exception of acetylated forms of S9.
Amino Acid Sequence↗