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71.
Localization of arachidonate 12-lipoxygenase in parenchymal cells of porcine anterior pituitary 总被引:2,自引:0,他引:2
N Ueda A Hiroshima K Natsui F Shinjo T Yoshimoto S Yamamoto K Ii K Gerozissis F Dray 《The Journal of biological chemistry》1990,265(4):2311-2316
12-Lipoxygenases oxygenate arachidonic acid producing its 12S-hydroperoxy derivative and are well known as platelet and leukocyte enzymes. When a peroxidase-linked immunoassay of the enzyme according to the avidin-biotin method was applied to the cytosol fractions from various parts of porcine brain, a considerable amount of the enzyme was found in the anterior pituitary. The enzyme level (about 200 ng/mg cytosol protein) corresponded to about 6% of the enzyme content in porcine peripheral leukocytes. Posterior and intermediate lobes showed about one-tenth of the enzyme level of anterior pituitary. Other parts of porcine brain contained the 12-lipoxygenase in amounts below 7 ng/mg cytosol protein. The cytosol fraction (0.7 mg of protein) of anterior pituitary produced 12S-hydroxy-5,8,10,14-eicosatetraenoic acid from 25 microM arachidonic acid in about 34% conversion at 24 degrees C for 5 min, giving a specific enzyme activity about 3 nmol/min/mg protein. Furthermore, various octadecapolyenoic acids were oxygenated almost as fast as the arachidonate 12-oxygenation. When anterior pituitary was investigated immunohistochemically with anti-12-lipoxygenase antibody, most of the immunostained cells were certain parenchymal cells with granules, which were not blood cells. These biochemical and immunohistochemical results provide a good reason for considering that 12-lipoxygenase does play an important role in pituitary function. 相似文献
72.
Hiroaki Matsui Takeshi Kato† Chosabro Yamamoto Keisuke Fujita ‡ Toshiharu Nagatsu† 《Journal of neurochemistry》1981,37(2):289-296
Abstract: This paper describes a new, sensitive assay for dopamine-β-hydroxylase (DBH) activity in human cerebrospinal fluid (CSF), serum and brain tissues by high performance liquid chromatography (HPLC) with electrochemical detection (ED). Dopamine (DA) was used as a substrate and was incubated under optimal conditions. Norepinephrine (NE) formed enzymatically from DA was isolated by a double-column procedure, the first column of Dowex-50-H+ and the second column of aluminum oxide. NE was adsorbed on the second aluminum oxide column and then eluted with 0.5 M-hydrochloric acid and assayed by HPLC-ED. Epinephrine (EN) was added to each incubation mixture as an internal standard, and this assay was therefore highly reproducible. The peak height in HPLC was linear from 500 fmol to 100 pmol of NE and EN. The lower limit of detection for NE formed enzymatically was about 30 pmol, which indicated that the sensitivity of this procedure was comparable to that of radioassay procedures. We applied the method to measurement of the activity of and examination of some of the characteristics of DBH in human CSF. DBH activity in CSF of Parkinsonian patients was lower than that of control patients. The properties of DBH in human CSF were similar to those in serum and adrenal medulla. 相似文献
73.
M Ueda 《Comptes rendus des séances de la Société de biologie et de ses filiales》1981,175(3):372-376
The effects of calcium and magnesium ions on the corticosterone binding to rat brain cytosol receptor protein(s) were investigated. The increasing amounts of CaCl2 or MgCl2 up to 5.0 mM were added, the specific [3H] corticosterone binding increased 1.3-fold and 1.5 respectively. The addition of MnCl2 and KCl did not affect this binding. The binding of corticosterone with rat brain cytosol receptor(s) were decreased by increasing amounts of EDTA and complete inhibition was observed at concentration equal to and greater than 2.5 mM. Inhibition of this binding by EDTA was less than by EGTA. Either theophylline or dibutyryl cyclic AMP had no effect on this binding. 相似文献
74.
Koshiro Yoshioka Mitsuo Fujimori Kiwamu Yamaoka Kazuyoshi Ueda 《International journal of biological macromolecules》1982,4(1):55-61
The electric birefringence and circular dichroism spectra of poly(l-ornithine hydrobromide) have been measured in ethanol/water, 2-propanol/water and tertiary butyl alcohol/water mixtures of various compositions. This charged polypeptide underwent a transition from the coil conformation to the helical conformation at high alcohol content in every case tested. Anomalous birefringence signals, indicative of a field-induced helix-to-coil transition. were observed at high electric fields only in the case of ethanol/water mixtures. The reversing-pulse electric birefringence of this polypeptide has been studied in ethanol/water mixtures and in neutral aqueous solution. Upon rapid reversal of the pulse field, no transient could be observed. This confirms that the electric-field orientation of poly(l-ornithine hydrobromide) results predominantly from the contribution of the counterion-induced dipole moment, regardless of its molecular conformations. It is very probable that the backbone permanent dipole moment of the helical conformation is largely suppressed by the counterion-induced dipole moment in the ionized form. 相似文献
75.
76.
An acromegalic patient with galactorrhea was treated with an ergot alkaloid, 2-Br-alpha-ergocryptine (CB-154). Serum prolactin decreased rapidly to normal level by CB-154 and the complete cessation of galactorrhea was noted. The inhibitory effect of CB-154 On growth hormone (GH) release was also noted, but slight. The mechanism of inhibitory action of CB-154 on both prolactin and GH secretion was discussed in connection with the experimental model of pituitary tumors, in which both hormones were produced by a single type of tumor cells. The discontinuation of CB-154 treatment was associated with the return of both prolactin and GH levels to the initial high values with resumption of galactorrhea. 相似文献
77.
The rubella seroimmunity status of a total of 1,204 students aged 12 to 19 in a junior and a senior high school in Osaka district was surveyed. Among these, 487 students (40.5%) were found to be seronegative (less than 1 : 8) by the hemagglutination inhibition (HI) test. A total of 287 students were immunized with live rubella vaccine, Biken lot No.7233. This caused an increased titer in all except one of the 262 seronegative students, while among 25 students with an initial HI antibody titer of 1 : 8 it caused more than 4-fold increase in 20 and 2-fold increase in 5. The vaccine caused no clinical manifestations, such as fever, rash or arthralgia. 相似文献
78.
The xanthurenic acid-insulin complex was found to have similar immunological properties to native Zn-insulin. This complex showed less hormonal activity on glucose metabolism in adipose tissue than native An-insulin, but its activity was increased by addition of Zn2+ ions. 相似文献
79.
80.
DCMU (N'-(3,4-dichlorophenyl)-N, N-dimethylurea) was testedfor effects on the metabolism of galactolipids in Chlorellaand chloroplasts isolated from higher plants. In Chlorella,DCMU affected galactolipid synthesis in the light more thanthat of other lipids, but it showed no effect on lipid synthesisin the dark. DCMU did not affect the turnover of galactolipidsin the light. In vitro studies using 14C-acetate or 14C-UDP-galactoseas a precursor showed that DCMU had no effect on the synthesisof gross lipid or galactolipids in chloroplasts isolated fromhigher plants. The significance of these observations are discussed. (Received September 21, 1974; ) 相似文献