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991.
992.
M Z Abedin S Ayad J B Weiss 《Biochemical and biophysical research communications》1981,102(4):1237-1245
993.
Michael G. Clark Sally D. Neville Dallas G. Clark 《Biochemical and biophysical research communications》1981,103(2):690-697
Hepatocytes were prepared from a strain of rats deficient in hepatic phosphorylase kinase and were used to assess the role of this enzyme in the adrenergic regulation of pyruvate kinase and gluconeogenesis. Epinephrine (10 μM) stimulated glucose output and gluconeogenesis from 1.8 mM lactate but did not significantly affect the concentration of hepatocyte glycogen. In addition epinephrine treatment led to an inhibition of pyruvate kinase. The stimulation of gluconeogenesis and the inhibition of pyruvate kinase by epinephrine were blocked by both α- and β-antagonists: similar effects with epinephrine were observed in cells from control animals. It is concluded that mechanisms for the adrenergic regulation of pyruvate kinase and gluconeogenesis are similar in hepatocytes from both phosphorylase kinase-deficient and normal rats. 相似文献
994.
Lee-Young Chau Hsin-Hsiung Tai 《Biochemical and biophysical research communications》1981,100(4):1688-1695
Release of arachidonate from 2-arachidonyl diglyceride by human platelet microsomes was investigated. Diglycerides labeled with 14C-stearate at sn-1 and with 3H-arachidonate at sn-2 were used as a substrate for microsomal diglyceride lipase. Diglyceride was deacylated first at sn-1 as evidenced by the accumulation of 2-arachidonyl monoglyceride but not of 1-stearoyl monoglyceride. Subsequent release of arachidonate from monoglyceride required the action of a monoglyceride lipase. Studies on substrate specificity indicated that diglyceride lipase utilized 2-arachidonyl diglyceride as the best substrate. 相似文献
995.
Paul A. Price Sharon A. Baukol 《Biochemical and biophysical research communications》1981,99(3):928-935
1,25-dihydroxyvitamin D3 increases serum levels of bone Gla protein (BGP). The maximal increase occurs 12 h after injection and is given by 350 ng 1,25(OH)2D3 per 180 g body weight. In both 2 and 11 month-old male rats, the maximal increase is about 3 times the normal level, while in 2 month old female rats, the maximal increase is 2 times the normal level. These effects of 1,25(OH)2D3 in rats parallel the previously described effects of the vitamin on BGP secretion by rat osteosarcoma cells in culture.BGP is the first bone-specific protein whose synthesis in animals is dramatically increased by 1,25(OH)2D3. The possible functions of BGP in the biological actions of 1,25(OH)2D3 on bone are discussed. 相似文献
996.
B. Birdsall A. Gronenborn G.M. Clore G.C.K. Roberts J. Feeney A.S.V. Burgen 《Biochemical and biophysical research communications》1981,101(4):1139-1144
The 3-carboxamido-13C resonance of NADP+ in its complex with dihydrofolate reductase and folate has been studied as a function of pH. At low pH a single resonance is observed, while at high pH two resonances are observed, neither of which has the same chemical shift as that seen at low pH. The rates of interconversion between the three states of the complex represented by these resonances are < 19 s?1 at 11°C. 相似文献
997.
998.
999.
F. J. Lopez Aparicio F. Zorrilla Benitez F. Santoyo Gonzalez 《Carbohydrate research》1981,90(2):315-318
The homogeneous, neutral polysaccharide isolated from the crude polysaccharide of the fruit pulp from bael (Aegle marmelos) contains arabinose, galactose, and glucose in the molar ratios of 2:3:14. The linkages among the different monosaccharide residues were established through methylation analysis and Smith-degradation studies of the polysaccharide. The anomeric configurations of the different glycosyl groups were determined by study of the chromium trioxide oxidation of the acetylated polysaccharide. Results of these experiments have been discussed in order to assess the structure of the neutral polysaccharide. 相似文献
1000.
The incubation of human peripheral blood lymphocytes (PBL) with the natural killer (NK)-sensitive MOLT-4 cell line results in PBL-target cell conjugate formation by certain lymphocyte subpopulations. Following velocity sedimentation, the PBL depleted of these conjugate-forming subpopulations are markedly diminished in the ability to mediate either antibody-dependent cellular cytotoxicity (ADCC) or NK activity. The immediate testing of highly pure PBL subpopulations isolated from the NK target conjugates does not reveal the expected recovery of augmented ADCC or NK levels. Following in vitro incubation, however, the PBL NK target-binding subpopulations do manifest augmented levels of both NK and ADCC, whereas the depleted PBL continue to display diminished NK and ADCC levels. In addition, the degree of augmented NK and ADCC levels recovered by the NK target-binding PBL subpopulations appears dependent on both the time and the temperature of in vitro incubation. Moreover, the ADCC recovery patterns are identical to those observed for NK activity regardless of the time and temperature of in vitro incubation. These results directly demonstrate that the PBL subpopulations isolated from certain NK target cells are functionally enriched in the ability to mediate from ADCC and NK activity. 相似文献