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排序方式: 共有1387条查询结果,搜索用时 15 毫秒
21.
Yuichiro Arai Se KyungKim Hiroyasu Kinemuchi Takeshi Tadano Shinetsu Satoh Nobunori Satoh Katsuyuki Oyama Kensuke Kisara 《Neurochemistry international》1990,17(4):587-592
The present study was carried out mainly to clarify whether the two amphetamine metabolites, p-hydroxyamphetamine (P-OHA) and p-hydroxynorephedrine (p-OHN) are taken up by mouse brain 5-hydroxytryptamine (5-HT) nerve terminals to inhibit type A monoamine oxidase (MAO-A) and then potentiate the abnormal behavior, head-twitch. Of the two metabolites, only intracerebroventricular p-OHA, at 80 μg/mouse, sufficient to cause a head-twitch response (HTR), appreciably inhibited MAO-A activity without affecting MAO-B activity in homogenates of the mouse striatum, hypothalamus and the rest of the forebrain; and p-OHN did not inhibit either type of MAO at the dose tested. Estimation of intra- and extrasynaptosomal MAO-A activity showed that both metabolites significantly inhibited only the intrasynaptosomal deamination of 5-HT by MAO-A with p-OHA being more potent. Taken together with our previous findings, these present results clearly indicate that p-OHA may accumulate in the 5-HT nerve terminals through the uptake system, and concomitantly inhibit MAO-A activity. These actions of p-OHA may increase intraneuronal 5-HT levels and then potentiate 5-HT release to cause interaction with the post-synaptic 5-HT receptors. 相似文献
22.
T Sasaki M Kishi M Saito T Tanaka N Higuchi E Kominami N Katunuma T Murachi 《Journal of enzyme inhibition》1990,3(3):195-201
Eight different di- and tripeptidyl aldehyde derivatives, each having at its C-terminus an aldehyde analog of L-norleucine, L-methionine, or L-phenylalanine with a preceding L-leucine residue, were synthesized and tested for their inhibitory effects on several serine and cysteine endopeptidases. These compounds showed almost no inhibition of trypsin, and only weak inhibition of alpha-chymotrypsin and cathepsin H, while they exhibited marked inhibition of cathepsin B less than calpain II congruent to calpain I less than cathepsin L, being stronger in this order. The mode of inhibition of these cysteine proteinases was competitive for the peptide substrate used and inhibitor constants (Ki) were calculated from the Dixon plot. The best inhibitors found were: 4-phenyl-butyryl-Leu-Met-H for calpain I (Ki, 36 nM) and calpain II (Ki, 50 nM); acetyl-Leu-Leu-nLeu-H for cathepsin L (Ki, 0.5 nM); acetyl-Leu-Leu-Met-H for cathepsin B (Ki, 100 nM). 相似文献
23.
Furukawa Toshiko; Koga Jinichiro; Adachi Takashi; Kishi Kunihei; Syono Kunihiko 《Plant & cell physiology》1996,37(7):899-905
In a study of various phytopathogenic fungi, we found that fungithat belong to the genus Rhizoctonia produce IAA efficientlyfrom tryptophan. R. solani Kühn MAFF-305219, in particular,produced large amounts of tryptophol (Tol), which was assumedto be a specific by-product of the indole-3-pyruvate (IPy) pathway,in addition to IAA. Therefore, this fungus seemed suitable foranalysis of the function and the regulation of the biosynthesisof auxin by a fungal pathogen. Under normal aerobic conditions,the ratio of IAA to Tol synthesized by this strain was higherthan that under less aerobic conditions. In metabolic studieswith various indole derivatives, R. solani converted L-tryptophanand indole-3-acetaldehyde to IAA and Tol, but other indole derivativeswere scarcely metabolized. These results suggest that both IAAand Tol are synthesized from tryptophan through the IPy pathwayin Rhizoctonia. (Received May 27, 1996; Accepted July 8, 1996) 相似文献
24.
Evolution of HCN from both rice ( Oryza sativa ) and cocklebur ( Xanthium pennsylvanicum ) seeds increased during a pre-germination period and preceded the evolution of (C2 H4 ). These two species were adopted as the representatives of starchy and fatty seeds, respectively. Ethylene promotes seed germination of many species. However, HCN evolution declined abruptly when the radicles emerged and before the peak in C2 H4 evolution. More-over, both rice and soybean ( Glycine max ) seeds showed some activity of β-cyanoalanine synthase (CAS, EC 4.4.1.9) even in the unimbibed dry state. The activities of CAS in the lower seed of cocklebur and in soybean seeds increased rapidly after emergence of the radicle. However, the CAS of rice seeds, with high activity in the dry state, exhibited a bimodal change, gradually decreasing until radicle emergence had occurred, but then increaing. It is thus likly that HCN evolution during initial imbibition may be derived from cyanogenic reserves and controlled by both pre-existing and subsequently-developing CAS. The exogenous application of C2 H4 stimulated the activities of CAS in both rice and upper cocklebur seeds and reduced their cyanogen contents. Therefore, the decline of HCN evolution after germination seems to be due to the increased activities of CAS by endogenously produced C2 H4 . 相似文献
25.
Haruo Takeshita Toshihiro Yasuda Daita Nadano Reiko Iida Masao Nakanaga Etsuko Tenjo Kazumi Sawazaki Koichiro Kishi 《Human genetics》1994,94(3):224-230
The main isozyme patterns of desialylated blood plasma or serum -l-fucosidase (FUCA) were found to be almost identical to those of semen, urine, placental extracts, and leukocyte lysates, when detected by polyacrylamide gel isoelectric focusing, and activity staining using the fluorogenic substrate 4-methylumbelliferyl--l-fucopyranoside. Three phenotypes (1, 2-1, and 2) determined from plasma samples were identical to the phenotypes from urine and leukocyte lysates from the same individuals. A population study of plasma samples collected from 485 Japanese individuals indicated that the frequencies of the FUCA11
* and FUCA12
* alleles were 0.7505 and 0.2495, respectively. The mean plasma enzyme activities (+SD) of the three phenotypes were 318.8 ± 116.7 nmol/ml per h for type 1, 268.0 ± 108.3 nmol/ml per h for type 2-1, and 233.2 ± 84.4 nmol/ml per h for type 2. The mean activities of types 1 and 2 suggest that, on average, the FUCA11
* gene product in plasma has about 1.4 times the activity of FUCA12
*. 相似文献
26.
Akemi Tsuda Masatoshi Ito Kazuko Kishi Hideyuki Shiraishi Hideo Tsuda Chuzo Mori 《Neurochemical research》1994,19(1):1-4
To investigate the mechanism of penicillin-induced convulsions, we have studied the effects of penicillin G (PC-G) on GABA-gated chloride ion influx in brain microsac preparations of mice. In the presence of 10–4 M GABA, PC-G inhibited GABA-gated chloride ion influx in a dose-dependent manner. The dose-response curve for GABA in the presence of 10–3 M PC-G was shifted rightward and there was a decrease in maximum response. The inhibitory effects of PC-G were not reversed by RO 15-1788, an antagonist of benzodiazepine (BZ) receptors, but were reversed by washing the microsac membranes. Therefore, PC-G probably exerts its proconvulsant effect by inhibiting GABA-gated chloride ion influx. However, it appears not to act through the BZ receptor of the GABA/BZ receptor complex. 相似文献
27.
John G. Frazier Harry L. Fierstine Sallie C. Beavers Federico Achaval Hiroyuki Suganuma Robert L. Pitman Yuichiro Yamaguchi Carlos Ma. Prigioni 《Environmental Biology of Fishes》1994,39(1):85-96
Synopsis Billfishes have long been known to impale a great variety of objects, but there are only two brief, obscure records of marine
turtles being speared. Details are presented on these two, as well as on two other confirmed records; data from two additional
unconfirmed records are also presented. In total, three species of marine turtles are known to have been impaled by three
species of billfishes; a fourth species of fish and a fourth species turtle are listed in an unconfirmed case. Records come
from the eastern and western Pacific as well as the eastern Atlantic. Of the four confirmed cases, the turtles survived in
two, and apparently died as an effect of the spearing in the other two. In three confirmed cases only the impaled rostrum
was encountered, and in one confirmed case the entire fish was found, with its rostrum piercing the turtle. There is no obvious
advantage — or clear disadvantage — involved in impaling turtles. It is argued that these attacks are accidental, and the
result of attempts made by the billfish to capture prey that are near the turtle. These spearings indicate that the chelonians
serve as shelters for prey animals on the high seas, and thus, are further evidence of the pelagic existence of marine turtles.
The impalings are evidence of a singular ecological role of the turtles — as live fish aggregation devices. 相似文献
28.
Bulb canker of garlic caused byEmbellisia allii was newly detected in Japan. Symptoms of the disease are described and the morphological characteristics of the causal fungus are illustrated and described. 相似文献
29.
30.
Naoyuki Nakahama Ryosuke Okano Yuichiro Nishimoto Yusuke Nakatani Asato Noishiki Naoki Ogawa 《Entomological Science》2023,26(2):e12545
Wetland biodiversity is currently declining on a global scale. Wetland biodiversity understanding is critical for determining the wetlands' conservation value. In this study, Macroplea Samouelle, 1819 (Coleoptera: Chrysomelidae) was discovered in Aomori Prefecture, Honshu Island, Japan. Only two Macroplea species have been recorded in Japan, M. japana (Jacoby, 1885) and M. mutica (Fabricius, 1792). Macroplea japana had been unrecorded for 60 years before being rediscovered in Honshu Island in 2022, and a single adult M. mutica female was discovered in Hokkaido Prefecture in 2003. The discovered individuals were concluded to be M. mutica based on morphological and molecular analyses. Although morphological differences were observed with the Eurasian M. mutica individuals, the male genitalia was nearly identical to M. mutica. For the molecular phylogenetic analysis based on COI and 28S sequences, Macroplea individuals in Japan were clustered with M. mutica on the Eurasian Continent. This is the first record of this species on Honshu Island (and the second in Japan), as well as the first record of adult males. This species would require conservation policies and additional distributional surveys. 相似文献