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991.
T C Peterson C N Williams D A Malatjalian 《Canadian journal of physiology and pharmacology》1991,69(12):1797-1803
We have previously reported that monocyte aryl hydrocarbon hydroxylase (AHH) activity is depressed in patients with liver disease and is decreased more in cirrhosis than in early stage liver disease. To determine if monocyte AHH activity reflects liver AHH activity, we studied an animal model of cirrhosis, i.e., yellow phosphorus induced cirrhosis in the pig. AHH activity was detectable in monocytes isolated from peripheral blood of normal pigs (0.32 +/- 0.13 nmol.mg-1 P.h-1, n = 11) and was comparable to the level of AHH activity in hepatic Kupffer cells isolated from wedge or needle biopsies of livers of normal pigs (0.38 +/- 0.21, n = 7). The AHH level in pig Kupffer cells was approximately 10% of the AHH level in hepatocytes and microsomes. To induce liver disease, pigs were administered yellow phosphorus (0.6 mg/kg) 5 days per week for 16 weeks. At 4 weeks of treatment, monocyte AHH activity was not different from control and liver histology was normal. Depression of monocyte AHH activity was evident at 8 weeks of treatment when liver fibrosis was seen histologically. At 12 weeks of treatment when histology revealed extensive liver fibrosis and collagen levels were elevated, the level of monocyte AHH activity was decreased 67% compared with controls. Similar changes were observed at 12 weeks in Kupffer cell AHH activity (86% decrease) and hepatocyte AHH activity (70% decrease) compared with controls. These results suggest that monocyte AHH activity reflects liver AHH activity and may be a good indicator of change in liver enzyme function in liver disease in the pig model of cirrhosis. 相似文献
992.
Isolation and characterization of monoclonal antibodies specific for the cardiac muscarinic acetylcholine receptor 总被引:1,自引:0,他引:1
C W Luetje C Brumwell M G Norman G L Peterson M I Schimerlik N M Nathanson 《Biochemistry》1987,26(22):6892-6896
A number of monoclonal antibodies were raised against the purified porcine atrial muscarinic acetylcholine receptor. The antibodies were shown to exhibit a high degree of specificity for the receptor by their ability to recognize the purified receptor but not other porcine atrial glycoproteins in enzyme-linked solid-phase immunosorptive assays and by immunoblot analyses. Several of the antibodies were able to quantitatively precipitate the muscarinic receptor in both pig and rat heart and a portion of the receptor from rat cerebellum but little if any receptor from rat cerebral cortex. Thus, these monoclonal antibodies not only exhibit specificity for the muscarinic receptor but also are specific for the cardiac receptor subtype. 相似文献
993.
994.
J G Ghazarian J E Martinex A C Gallardo J A Kulkoski B L Peterson 《The Journal of biological chemistry》1980,255(17):8275-8281
995.
Identification of the ligand-exchange process in the alkaline transition of horse heart cytochrome c. 总被引:1,自引:1,他引:0 下载免费PDF全文
Magnetic-circular-dichroism (m.c.d.) spectra over the wavelength range 300-2000 nm at room temperature and at 4.2K of horse heart cytochrome c are reported at a series of pH values between 7.8 and 11.0, encompassing the alkaline transition. The effect of glassing agents on the e.p.r. spectrum at various pH values is also reported. Comparison of these results with spectra obtained for the n-butylamine adduct of soybean leghaemoglobin support the hypothesis that lysine is the sixth ligand in the alkaline form of horse heart cytochrome c. The m.c.d. and e.p.r. spectra of horse heart cytochrome c in the presence of 1-methylimidazole have also been examined. These studies strongly suggest that histidine-18, the proximal ligand of the haem, is the ionizing group that triggers the alkaline transition. Low-temperature m.c.d. and e.p.r. spectra are also reported for Pseudomonas aeruginosa cytochrome c551. It is shown that no ligand exchange takes place at the haem in this species over the pH range 6.0-11.3. 相似文献
996.
997.
Enzymatic omega-oxidation. II. Function of rubredoxin as the electron carrier in omega-hydroxylation 总被引:13,自引:0,他引:13
J A Peterson M Kusunose E Kusunose M J Coon 《The Journal of biological chemistry》1967,242(19):4334-4340
998.
Water extract of stinging nettle (Urtica dioica) has a growth stimulating effect on plants. This investigation elucidated effects of nettle water on uptake and transport
of N, P and K. Tomato plants (Solanum lycopersicum L. cv. Dansk export) were grown in sand culture 6–8 weeks. Plants were supplied with nettle water and nutrient solution was
used as a control medium. Uptake and transport of N, P and K+ were determined with isotopes (15N,32P and86Rb+ as a tracer for K+) and ion-selective electrodes and in exudation experiments.
A 15% higher uptake of nitrogen (15N assay) was found after nettle water treatment compared with the nutrient solution control. The total amount of nitrogen
was also higher in plants cultivated with nettle water. Transport of inorganic and organic nitrogen, measured in exudation
experiments, was more than 50% higher for plants supplied with nettle water compared with plants supplied with nutrient solution.
In contrast, nettle water had no effect on uptake, transport or total amount of phosphorus and potassium in the plants.
Experiments in hydroculture showed that nettle water had a strong pH-elevating effect. Uptake of NH
4
+
was strongly stimulated by nettle water compared with nutrient solution. By holding pH at a constant level during the uptake
period for 6 h, the uptake of NH
4
+
from nettle water was significantly lower when no adjustment of pH was made. Consequently a good deal of the NH
4
+
uptake enhancement by nettle water could be explained by pH-stimulation. Assays with the uncoupler/inhibitor 2,4-dinitrophenol
(DNP) and dichlorophenyl-dimethyl-urea (DCMU) showed that uptake of nitrogen from nettle water was less metabolically-linked
than uptake from a corresponding nutrient solution. All together, nettle water seems to stimulate the uptake of nitrogen,
but not phosphorus or potassium. 相似文献
999.
1000.
Infection of Escherichia coli K-12 (λ) by bacteriophage results in an altered labeling pattern of phospholipids in the host cell. Although the overall incorporation of 32Pi into phospholipids is decreased by infection, the relative amounts of phosphatidylglycerol and cardiolipin are increased. Phospholipid changes occurring at later stages in the lytic cycle of infected bacteria are more prominent than those at earlier time intervals. The uptake of 32Pi into phospholipids of cells infected with T4Bs and endolysin-negative mutants was similar to that observed with the wild-type phage, suggesting that the development of resistance to lysis from without and the repair of mucopeptides are not responsible for the phospholipid changes. The metabolism of phospholipids in uninfected cells treated with cyanide was similar to that of infected cells, indicating that part of the phage-induced alterations may be a consequence of impaired respiration. 相似文献