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11.
Effects of barbiturates on the inhibitory action of GABA on excitatory response of the stomach to stimulation of vagal afferent fibers in cat 总被引:1,自引:0,他引:1
Effects of barbiturates on the inhibitory action of GABA to the hexamethonium-resistant excitatory response of the stomach to stimulation of the vagal afferent fibers were studied in cats. Inhibition of the hexamethonium-resistant excitatory response by GABA were compared under alpha-chloralose, alpha-chloralose-phenobarbital (PhB), and alpha-chloralose-pentobarbital (PB)-anesthesia in cats. The ID50 of GABA on the hexamethonium-resistant excitatory response was not significantly affected by PhB, but reduced by PB. Both picrotoxin and bicuculline antagonized the effects of GABA. The present experiments demonstrated that PB potentiated the inhibitory effect of GABA on the hexamethonium-resistant excitatory response of the stomach, and suggested that the potentiation by PB may be due to activation of GABA-receptor-ionophore complex. 相似文献
12.
Inherited hydrocephalus in Csk: Wistar-Imamichi rats; Hyd strain: a new disease model for hydrocephalus 总被引:2,自引:0,他引:2
Hydrocephalic rats were found in a breeding colony of Csk: Wistar-Imamichi strain rats. In males, the hydrocephalus were serious and could be detected from 7 days after birth. Survival was 3-4 weeks. In females, the hydrocephalus was moderate, there was no abnormal external appearance, and the rats were able to mature. Ventricular dilatation was excessive in males but moderate in females. The total frequency of hydrocephalus was 34.3% in both males and females. Breeding data indicated that this disease is heritable and is single dominant and X-linked (symbol, Hyd). The female moderate hydrocephalics could be detected by progeny tests without examining brain sections. No evidence of developmental anomaly was observed in the ventricles. This hydrocephalus was classified as being of the communicating type, and this strain was named the Hyd strain as an animal model for human hydrocephalus. 相似文献
13.
A method for detecting the optimum day for mating in the rat was investigated. Cyclic changes of electrical impedance of vagina (EIV) were studied in the rats. EIV indicated high value (over 3,000 omega) only at proestrus, and it was lower (under 3,000 omega) at other stage of estrous cycle. These results apparently indicate that measuring the EIV made to distinguish proestrus from other phases of estrous cycle. The female caged with male showed high copulation rate (88 approximately 96%) when her EIV had been over 3,000 omega. 相似文献
14.
Transfer of granulomatous inflammation with nonviable preparations of schistosome granulomas in naive mice 总被引:1,自引:0,他引:1
Hepatic granulomas of euthymic (nu/+) mice infected with Schistosoma mansoni were freeze-dried or freeze-thawed 3 times and transplanted subcutaneously into naive nu/+ and athymic (nu/nu) mice. The grafted sites, studied histologically, showed formation of organized granulomas in nu/+ mice similar to donor granulomas as observed after grafting of freshly isolated granulomas. On the other hand, in nu/nu mice, the nonviable transplants elicited small and disorganized granulomas, like hepatic granulomas in nu/nu mice with schistosomiasis, but different from fresh nu/+ transplants in nu/nu skin. The findings indicate viable cells are not required for transfer of granulomatous reactions, but T cells are needed for full expression. 相似文献
15.
Takashi Yutsudo Hisao Kurazono Chihiro Sasakawa Masanosuke Yoshikawa Makoto Iwaya Tae Takeda Yoshifumi Takeda 《FEMS microbiology letters》1987,48(1-2):273-276
Abstract A Vero toxin (VT2 or Shiga-like toxin II)-converting phage was isolated from Escherichia coli 0157: H7 strain J-2. Nontoxigenic E. coli C600 produced VT2 when lysogenized with the toxin-converting phage. Eco RI fragments of the phage DNA were ligated with Eco RI-digested pBR322 or pUC118 and were transformed into E. coli MC1061 or MV1184. Transformants exhibiting VT2 production commonly contained a 4.6 kb Eco RI fragment. It was found that a 2.3 kb Kpn I- Sph I fragment coded VT2 production and that this fragment hybridized weakly with the 2.1 kb fragment encoding VT1. 相似文献
16.
L-Histidinol phosphate aminotransferase from Salmonella typhimurium. Kinetic behavior and sequence at the pyridoxal-P binding site 总被引:2,自引:0,他引:2
A coupled assay with alpha-hydroxyglutarate dehydrogenase was used to analyze the kinetic behavior of histidinol phosphate aminotransferase from Salmonella typhymurium. Data obtained from studies of initial velocity, inhibition by products or substrate analogues, isotope exchange rates, and the determination of the equilibrium constant were consistent only with a Ping-Pong Bi Bi mechanism. Variations in inhibition patterns by different substrate analogues indicate that the microenvironment about the pyridoxal phosphate and the pyridoxamine phosphate forms of histidinol phosphate amino-transferase are different, and favor the presence of one active site with partially overlapping substrate-binding subsites for these 2 forms of the enzyme. Histidinol phosphate aminotransferase also catalyzes decomposition of beta-chloro-L-alanine to pyruvate, NH3 and Cl-; no transamination of this substrate occurs and inactivation of the enzyme accompanies this reaction. After reduction of histidinol-P aminotransferase with [3H]NaBH4, carboxymethylation, and tryptic digestion, one major radioactive peptide absorbing at 325 nm was isolated. Its primary structure was determined to be TLSK*AFALAGLR, where K* is the P-pyridoxyllysine residue. Although this peptide is only 30-40% homologous with the corresponding segment reported for other transaminases, all of these peptides are similar in placement of an hydroxyamino acid residue three residues upstream from the lysine residue, and in the cluster of hydrophobic amino acid residues immediately following the lysine residue. 相似文献
17.
N Yoshizuka M Yoshimura S Tsuchiya K Okamoto Y Kobayashi T Osawa 《Cellular immunology》1989,123(1):212-225
A human T cell hybridoma clone, D6-18, producing high levels of macrophage chemotactic factor (MCF) was established by the emetine-actinomycin D selection method. MCF was found to be present not only in the culture medium but also in the cell lysate of D6-18 cells. The secretion of the MCF from D6-18 cells was effectively inhibited by disodium cromoglycate, which is an inhibitor of the degranulation of mast cells, suggesting that MCF is stored in granules. The MCF of D6-18 cells was purified from the sonicated cell lysate by ion-exchange chromatographies and high-performance liquid chromatography. The amino acid sequence of the purified MCF was revealed to be WLGREDGSE or WLGRQDGSE. The synthetic peptide WLGREDGSE showed chemotactic activity against guinea pig macrophages and human monocytes at the concentration of about 10(-8) M. 相似文献
18.
F Suzuki S Miyazaki M Uozumi N Okamoto S Yamashita K Murakami Y Nakamura 《FEBS letters》1989,256(1-2):47-50
The release of prorenin as well as renin from rat renal slices was confirmed by a rat prorenin-prosegment ELISA system and an assay system for determining the renin activity. A significant increase of the prorenin release was found by adding rat submandibular gland extract to the slice medium, indicating the existence of a prorenin-releasing stimulator (PRS) in the extract. The pI and molecular mass of PRS were 8.5-8.7 and 28-30 kDa, respectively. The PRS was completely inactivated by boiling or a proteinase treatment. 相似文献
19.
Isolation and Characterization of an Enterobacter cloacae Strain That Reduces Hexavalent Chromium under Anaerobic Conditions 总被引:12,自引:6,他引:6 下载免费PDF全文
Pi-Chao Wang Tsukasa Mori Kohya Komori Masanori Sasatsu Kiyoshi Toda Hisao Ohtake 《Applied microbiology》1989,55(7):1665-1669
An Enterobacter cloacae strain (HO1) capable of reducing hexavalent chromium (chromate) was isolated from activated sludge. This bacterium was resistant to chromate under both aerobic and anaerobic conditions. Only the anaerobic culture of the E. cloacae isolate showed chromate reduction. In the anaerobic culture, yellow turned white with chromate and the turbidity increased as the reduction proceeded, suggesting that insoluble chromium hydroxide was formed. E. cloacae is likely to utilize toxic chromate as an electron acceptor anaerobically because (i) the anaerobic growth of E. cloacae HO1 accompanied the decrease of toxic chromate in culture medium, (ii) the chromate-reducing activity was rapidly inhibited by oxygen, and (iii) the reduction occurred more rapidly in glycerol- or acetate-grown cells than in glucose-grown cells. The chromate reduction in E. cloacae HO1 was observed at pH 6.0 to 8.5 (optimum pH, 7.0) and at 10 to 40°C (optimum, 30°C). 相似文献
20.