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101.
102.
催产素在脊髓水平对电针镇痛的影响 总被引:3,自引:0,他引:3
采用玻璃微电极胞外记录和脊髓表面给药的方法观察了催产素(OT)、抗催产素血清(AOTS)以及电针穴位对背角神经元伤害性诱发放电的影响。结果表明:电针穴位或脊髓表面施加OT可部分抑制脊髓背角神经元的伤害性诱发放电;在电针的基础上施加OT则明显加强电针的抑制效应;相反,用AOTS预处理后,电针的抑制作用放取消。提示OT在脊髓水平参与了对痛觉信息的调制,并与一定频率的针刺镇痛有关。 相似文献
103.
R. Van Potter Theresa Ruh Evanson Debra P. Gayda James A. Gurr 《In vitro cellular & developmental biology. Plant》1984,20(9):723-731
Summary The induction and decay of ornithine decarboxylase (ODC) by insulin and asparagine in cultures of H4-II-EC3 (H35) hepatoma
cells was studied in a modified Waymouth medium in the presence of fetal bovine serum (FBS) and in serum-free media. The insulin
response was enhanced by the presence of asparagine although the effect of asparagine was not so much on the initial increase
as it was on a slowing of the decline after the maximum was reached at 6 to 8 h after the supplements were added together
with fresh medium. In all cases the initial ODC activity was zero at zero time for addition of media and supplements, and,
after reaching the maximum, activity declined to near zero by 24 h. Fetal bovine serum gave induction that followed a similar
time course but was inferior to the combintion, of insulin plus asparagine and, in fact, FBS inhibited the latter response.
Putrescine (the product formed from ornithine by ODC), at 10−5
M, markedly inhibited the induction of ODC by insulin or FBS, but the inhibition was less when asparagine was present.
This work was supported in part by Grants CA-07175, CA-22484, and CA-17334 from the National Cancer Institute. D. P. G. is
a Predoctoral Fellow at the Food Research Institute, supported by a fellowship from the Monsanto Fund and by NIH Grant R01-AI
15693 to Prof. Michael W. Pariza, Food Research Institute, University of Wisconsin, Madison. 相似文献
104.
A 250-kilodalton cellular protein is induced by progestins in two human breast cancer cell lines MCF7 and T47D 总被引:1,自引:0,他引:1
We have studied the effect of R5020, a synthetic progestin, on the biosynthesis of cellular proteins extracted from the MCF7 and T47D human breast cancer cells, using gel electrophoresis. R5020 stimulates the synthesis, as measured after [35S]-methionine labelling, and the accumulation, as shown by silver staining, of a protein of molecular weight approximately equal to 250,000. The increase of the labelled 250-kilodalton protein was rapid (3 hours) and after 3 days this protein represented approximately equal to 6% of the total cellular proteins (approximately equal to 1 microgram/150,000 cells). The induction of the 250-kilodalton protein was obtained by physiologically active concentrations of several progestins and high concentrations of 5 alpha-dihydrotestosterone but not by estradiol or dexamethasone. It was inhibited by R486 , a progestin antagonist, but not by flutamide, an androgen antagonist. These results indicate a mediation by the progesterone receptor. The 250-kilodalton protein appears to be an excellent probe to study in cell culture the mechanism of action of progestin on human cells. 相似文献
105.
Evidence for intracellular formation of angiotensins: coexistence of renin and angiotensin-converting enzyme in Leydig cells of rat testis 总被引:7,自引:0,他引:7
K N Pandey K S Misono T Inagami 《Biochemical and biophysical research communications》1984,122(3):1337-1343
Leydig cells were purified from rat testes by discontinuous metrizamide density gradient and were shown to contain renin (EC 3.4.99.1), angiotensin-converting enzyme (dipeptidyl carboxypeptidase, (EC 3.4.15.1), and the peptide hormone angiotensins I, II and III as determined by the combined HPLC and radioimmunoassay. In germinal cells only angiotensin II (AII) was found at a significant level. These findings provide evidence for intracellular formation of AII in testicular cells and demonstrate that an intracellular renin-angiotensin system exists in normal non-transformed cells. 相似文献
106.
The conditions used in some immunoblot procedures can fail to detect calmodulin, S100 proteins, and other proteins with similar physical properties. We describe here some of the basis of this difficulty, and provide an immunoblot protocol that allows the rapid and reproducible detection of calmodulin and S100 beta in crude biological samples. These proteins are rapidly transferred from sodium dodecyl sulfate-polyacrylamide gels to membrane matrices, and retention on the matrix is enhanced by a glutaraldehyde fixation step. Either nitrocellulose or a positively charged membrane filter (ZetaProbe) can be used as the immobilizing matrix. By combining microslab gel electrophoresis, 30 min electrophoretic transfer, and glutaraldehyde fixation of nitrocellulose paper, an immunoblot analysis can be done in an 8-hr day. 相似文献
107.
Vesicles having diameters from 20 to 200 nm were prepared from egg-yolk phosphatidylcholine (PC) and were separated as well as analyzed by methods that can be carried out with standard laboratory equipment. Gel-chromatography on Sephacryl S 1000 was adapted for expeditious size analysis of vesicles as well as for isolation of vesicle populations having a narrow range of diameters. The internal volume of vesicles was derived from enzymic tests for PC and for glucose encapsulated. Size analysis and enzymic determinations provided a convenient check for the lamellarity of membranes produced.Fatty acids and fatty acid binding proteins (FABPs) must interact in vivo in the presence of cellular membranes. As a model, interactions between unilamellar vesicles, anthroyloxypalmitic acid (A16:0) and FABPs were studied with the aid of gel-chromatographic methods elaborated and of fluorescence spectroscopy. FABP from bovine heart donated A16:0 to membranes, whereas FABP from bovine liver removed this fatty acid from vesicle membranes. The results revealed characteristic differences between cardiac and hepatic FABPs with regard to binding a fatty acid. 相似文献
108.
F Zeytin C Mougin P Brazeau N Ling 《Biochemical and biophysical research communications》1984,120(2):540-547
The effects of forskolin and cholera toxin on the regulation of cAMP release were studied in a neurotensin-secreting rat C-cell line. The interaction of these agents with norepinephrine, a potent neurotensin secretagogue, was also investigated. Forskolin stimulated cAMP release 10(2)-10(3) fold while it increased neurotensin release 2-3 fold. Cholera toxin caused a 10(2)-10(3) fold increase in cAMP release and had no effect on neurotensin release. We conclude that the 44-2 C-cells provide a new model for studying the regulation of the concomitant (via forskolin) or independent (via cholera toxin) secretion of cyclic AMP and/or neurotensin. 相似文献
109.
Salvatore Passarella Anna Atlante Maria Barile Ernesto Quagliariello 《Biochemical and biophysical research communications》1984,121(3):770-778
GABA added to rat brain mitochondria causes oxidation of intramitochondrial NAD(P)H as well as inducing glutamate efflux from the mitochondrial matrix. The rate of NAD(P)H oxidation shows saturation characteristics, depends on GABA transport across the mitochondrial membrane and is inhibited by non-penetrant compounds and by the metal-complexing agent bathophenanthroline. These results show the existence of a specific GABA carrier. Inhibition studies strongly suggest the existence of two separate binding sites, namely the GABA binding site and the dicarboxylates binding site, as well as suggest the presence of a metal ion (ions) at GABA binding site. The occurrence of a GABA/GLUTAMATE antiport is proposed which allows a cyclical route to account for GABA synthesis and degradation in brain. 相似文献
110.
Janet Silnutzer David W. Barnes 《Biochemical and biophysical research communications》1984,118(1):339-343
Purified human serum spreading factor preparations consisting of two immunologically-related, biologically-active proteins of molecular weights approximately 65,000 and 75,000 were incubated with purified hydrolytic enzymes: papain, neuraminidase and thrombin. Biologically active products of the enzymatic digestions were obtained in each case. Digestion of serum spreading factor preparations with thrombin produced a single active form of molecular weight approximately 57,000. Generation of a single molecular weight form of serum spreading factor by thrombin cleavage of the two higher molecular weight forms should simplify studies of the biochemistry and biology of this protein, and may represent a reaction of physiological significance. 相似文献