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131.
The effect of 2-bromopalmitate, an inhibitor of fatty acid oxidation, on progesterone synthesis in isolated luteal cells was studied. Incubation of the cells with increasing concentrations (0 – 2 mM) of the inhibitor resulted in an initial enhancement of progesterone synthesis, both in the presence and absence of LH (1 μg/m1). In the LH-treated cells, this stimulation in steroid synthesis becomes markedly impaired at 2 mM 2-bromopalmitate. In the control cells, however, progesterone synthesis was sustained at the elevated level. At high concentrations of 2-bromopalmitate, the stimulatory effect of LH (relative to the controls) on steroidogenesis was progressively diminished, until it was completely abolished at an inhibitor concentration of 2 mM. The oxidation of labelled palmitic acid by luteal cells was also effectively inhibited by 2-bromopalmitate (1 mM). The results indicate that the steroidogenic effect of LH is mediated, in part, by fatty acid oxidation, and were explained in terms of the interaction between carbohydrate and fatty acid oxidation in supporting ovarian steroidogenesis. 相似文献
132.
The ability of CO2 to inhibit respiration and growth of representative strains of seven species of meat spoilage bacteria was examined. Enterobacter and Microbacterium thermosphactum were unaffected by CO2. Both respiration and growth of the other species were inhibited. With four of the species (fluorescent and nonfluorescent Pseudomonas, Alteromonas putrefaciens, and Yersinia enterocolitica), the inhibition pattern in a complex medium was similar, and inhibition was incomplete and reached a maximum level at comparatively low concentrations of CO2. With Acinetobacter, inhibition continued to increase with increasing CO2 concentration. The degree of inhibition with a constant concentration of CO2 in solution increased with decreasing temperature for all CO2-susceptible species except the nonfluorescent Pseudomonas. Anaerobic growth of CO2-susceptible facultative anaerobes was unaffected by CO2. 相似文献
133.
When flax seedlings are decapitated above cotyledons and three days later one of the two cotyledons is removed then the remaining
cotyledon stimulates in four to five days growth of its axillary bud. It has been found that content of endogenous cytokinins
was higher in the stimulated bud as compared with the other one already 12 h after the cotyledon removal.
Flax seedlings decapitated under cotyledons regenerate adventitious buds on thy hypocotyl stump during 5–6 days. The endogenous
fytohormonal preparation of this regeneration was investigated in the 20 mm apical part of the hypocotyl stump. Decrease in
auxin and increase in gibberellins was already found during the first day after decapitation while the level of cytokinins
increased as late as three days after the apex removal. 相似文献
134.
[3H]Mepyramine binds with high affinity to membranes from brain of human, rat, guinea-pig, rabbit and mouse with drug specificity indicating an association with histamine H1receptors. Considerable species differences occur in the affinity of [3H]mepyramine, with guinea-pig and human having 34 times greater affinity than rat, mouse or rabbit. The greater affinity of [3H]mepyramine in guinea-pig than in rat is attributable both to faster association and slower dissociation rates in guinea-pig. Species differences in affinity for H1 receptor sites occur for some antihistamines but not for others. Some tricyclic antidepressant and neuroleptic drugs are extremely potent inhibitors of [3H]mepyramine binding, exceeding in potency any H1 antihistamines examined. The tricyclic antidepressant doxepin and the neuroleptic clozapine are the most potent of all drugs examined in competing for [3H]mepyramine binding. The regional distribution of specific [3H]mepyramine binding differs considerably in the various species examined. 相似文献
135.
Angele V. McGrady Robert Yonker S. Y. Tan Thomas H. Fine Marilynn Woerner 《Applied psychophysiology and biofeedback》1981,6(3):343-353
The effect of EMG biofeedback-assisted relaxation on blood pressure and selected biochemical parameters was evaluated in 38 patients with essential hypertension. Training consisted of 8 weeks of biofeedback and home practice of relaxation exercises. Mean blood pressure decreased in the experimental group from 144/90 to 133/84 mm Hg while the control group remained unchanged. Statistically significant decreases in the experimental group also occurred in muscle tension levels, in plasma aldosterone, and in urinary cortisol. Both aldosterone and cortisol are secreted by the adrenal cortex. It was concluded that the technique taught to the experimental group produced a reduction in skeletal muscle tension and a decrease in stress responding mediated by the adrenal cortex.This work was supported by the Northwestern Ohio Heart Association Grant No. 93298. It was presented as a citation paper at the meetings of the Biofeedback Society in 1979 and 1980. 相似文献
136.
Wolfgang Hartmann Ingrid Tan Aloys Hüttermann Hans Kühlwein 《Archives of microbiology》1977,114(1):13-18
The properties of seven enzymes were studied in extracts from Myxobacter AL-1. The enzymes were isocitrate dehydrogenase (E.C. 1.1.1.42), succinate dehydrogenase (E.C. 1.3.99.1), alkaline phosphatase (E.C. 3.1.3.1), -glucosidase (E.C. 3.2.1.20), -glucosidase (E.C. 3.2.1.21), -galactosidase (E.C. 3.2.1.23), and N-acetyl-glucosaminidase (E.C. 3.2.1.30). Four of these enzymes: isocitrate dehydrogenase, -glucosidase, -glucosidase, and -galactosidase are cytosolic enzymes. Succinate dehydrogenase was found to be located on the cytoplasmic membrane system, whereas alkaline phosphatase and N-acetyl-glucosaminidase were considered as enzymes which bind the outer membranes resp. the cell wall. During the cell cycle, all enzymes have a pattern of discontinuous activity increase. Succinate dehydrogenase and isocitrate dehydrogenase exhibit a stepwise increase of activity, whereas the other enzymes follow the pattern of a peak enzyme. 相似文献
137.
Nineteen patients who had completed their course of dermatattoo treatment for the camouflage of port-wine hemangioma were evaluated at an average of 3.1 years following completion of treatment. A panel of 7 people evaluated preoperative and postoperative photographs and judged that none of the patients were more than "50 percent improved" in the camouflaging of their hemangioma, and that most of them (15 out of 19) were either "not improved" or "25 percent improved," as compared to their original photographs. We cannot rule out the possibility that this treatment may be effective in adults, as all of our patients at the time of their first treatment were between the ages of 4 and 20 years; and most of them were between 6 and 10 years old. On the basis of this evaluation, we no longer recommend the technique of dermatattoo for camouflage of port-wine hemangioma in patients in the younger age group. 相似文献
138.
139.
Lasse Ryhänen Elaine M.L. Tan Sirpa Rantala-Ryhänen Jouni Uitto 《Archives of biochemistry and biophysics》1982,215(1):230-236
Chick embryo sterna, which actively synthesize type II procollagen, were pulse-labeled with radioactive proline; protein synthesis was then inhibited by unlabeled proline and cycloheximide. After the inhibition of protein synthesis, several amino acids, polyamines, or structurally related compounds were added to the incubation medium. The conversion of procollagen, first to two intermediates, pC-collagen and pN-collagen, and then to collagen, was monitored by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis. The addition of 50 mm β-alanine, arginine, asparagine, glutamine, hydroxylysine, lysine, or ornithine, as well as agmatine, ?-aminocaproic acid, S-2-aminoethylcysteine, cadaverine, canavanine, putrescine, or spermine clearly inhibited the removal of the carboxy-terminal extension and pC-collagen accumulated; the removal of the amino-terminal extension was not affected. The inhibition of the conversion was reversible and unaffected by fetal calf serum. The results suggest that the conversion of type II procollagen to collagen requires at least two separate proteinases for the removal of amino-terminal and carboxy-terminal extensions. The results further suggest that naturally occurring molecules may be used to modulate the rate of conversion of procollagen to collagen, and development of analogs of these compounds may provide the means to interfere with excessive deposition of collagen in diseases with tissue fibrosis. 相似文献
140.
The chemical identity of the immunoreactive LHRH-like peptide biosynthesized in the human placenta 总被引:5,自引:0,他引:5
Freshly obtained human placental trophoblasts were minced and pulselabeled for 30 min at 37°C with tritiated L-Tyrosine. After homogenisation, the crude extract was centrifuged and deproteinized with 10% TCA. The supernatant was defatted and the peptides concentrated through hydrophobic binding on ODS-silica cartridges. The bound, crude peptide extract was eluted and subjected to gradient, reverse-phase High Performance Liquid Chromatography. The fractions corresponding to the absorption peak of reference, synthetic LHRH were collected and extensively purified to radioactive homogeneity by further multiple HPLC. After digestion with pyroglutamate aminopeptidase, the resulting nonapeptide was manually sequenced by dansyl-Edman degradation. All the incorporated radioactivity was found to reside exclusively in residue number 4 of the nonapeptide; thus establishing for the first time the primary sequence of biosynthetic placental LHRH as: pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2, identical to its hypothalamic counterpart. 相似文献