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The synthesis, high affinity uptake and degradation of GABA were compared with GABA content measured simultaneously in the nigras of unoperated, hemitransected and kainate-treated rats. In intact animals nigral GABA concentration was linearly related to glutamate decarboxylase activity, but not to GABA aminotransferase (GABA-T) or GABA uptake. One week after hemitransection all three parameters showed a linear reduction with GABA content, suggesting striatonigral GABA neurones may account for as much as 90% of the GABA and GAD, 31% of the GABA-T and 58% of GABA uptake sites in whole nigra. Nigral kainate treatment unexpectedly reduced all four parameters in parallel by as much as 50%, consistent with the formation of an unselective lesion. 相似文献
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Catharanthine and akuammicine, together with ajmalicine and strictosidine, were isolated from a culture strain of Catharanthus roseus suspension cells. The biosynthetic capability of the cultured cells to produce akuammicine, catharanthine and vindoline was confirmed by feeding experiments with dl-tryptophan-[3-14C] to yield the radioactive alkaloids. 相似文献
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Roxanne Deslauriers Harold C. Jarrell R.Andrew Byrd Ian C.P. Smith 《Biochemical and biophysical research communications》1980,95(3):1211-1217
studies of have shown that encysting cells release polyphosphate into the encystment medium. Mature cysts contain low levels of polyphosphate, as do vegetative cells. Young cysts (7 days) show detectable levels of nucleotide diphosphates and triphosphate similar to those observed in vegetative cells. Mature cysts (90 days) show only excreted polyphosphate as well as a component which has a chemical shift of a phosphodiester. The inorganic phosphate peak in the cyst shows that the cyst milieu is liquid-like and that the intracellular environment maintains a pH between 6 and 7.5 in the presence of extracellular values from 4 to 9. 相似文献
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Terry A. Potter Suzanne M. Watt Antony W. Burgess Ian F. C. McKenzie 《Immunogenetics》1979,8(1):461-473
Serological analysis of highly purified (>97%) mouse peritoneal exudate neutrophils using a protein-A rosetting technique, showed that these cells possessed the surface phenotype: Ig–, Thy-1–, Ly-1–, Ly-2–, Ly-3–, Ly-4+, Ly-5+, Ly-6+, Ly-7–, Ia–, FcR+ and C3R+. 相似文献