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61.
Michael Fernandes Gaddo Onesti Roberto Fiorentini Giuseppe Bellini Anne B. Gould Kwan Eun Kim Charles Swartz 《Life sciences》1977,20(4):623-626
Renal hypertension was induced by ligation of the aorta between renal arteries in rats sympathectomized with 6-hydroxydopamine. In the early phase, equally severe hypertension developed in the denervated group as compared to innervated controls. Later, blood pressure was lower in the denervated rats. Initially, increases in plasma renin were seen in both groups; the levels, however, were markedly lower in the denervated rats. Later, the renin levels were similar and not different from baseline. It is concluded that adrenergic neural activity is not essential in the development of renal hypertension; the maintenance of the chronic state, however, depends in part on adrenergic innervation. 相似文献
62.
Alan R. Gould 《Planta》1977,137(1):29-36
The effects of temperature on the cell cycle of Haplopappus gracilis suspension cultures were analysed by the fraction of labelled mitoses method. Sphase in these cultures shows a different temperature optimum as compared to optima derived for G2 and mitosis. G1 phase has a much lower Q10 than the other cell cycle phases and shows no temperature optimum between 22 and 34° C. These results are discussed in relation to a transition probability model of the cell cycle proposed by Smith and Martin (Proc. Natl. Acad. Sci. USA 70, 1263–1267, 1973), in which each cell has a time independent probability of initiating the transition into another round of DNA replication and division. The implications of such a model for cell cycle analysis are discussed and a tentative model for a probabilistic transition trigger is advanced.Abbreviations FLM
Fraction of labelled mitoses
- TB
Total B-phase 相似文献
63.
In a single-blind controlled clinical trial patients with optic neuritis caused by demyelination were given a single retrobulbar injection of triamcinolone. Though the treated group showed a trend towards more rapid recovery of vision than the controls, there was no significant difference in visual acuity, colour vision, or visual fields during the first six months after treatment. We conclude that routine use of corticosteroids is not justified in unilateral optic neuritis when vision in the other eye is good. Shortening the period of visual disability in bilateral disease or unilateral disease when vision in the other eye is poor, however, may be justifiable. 相似文献
64.
65.
Kinetics of protein-mediated transfer of rat pancreatic microsomal phosphatidylinositol to liposomes
Pancreatic microsomes were isolated from fasted and pilocarpine-injected rats and the microsomal phosphatidylinositol radiolabelled with myo-[2-3H]inositol by isotopic exchange. A standard reaction mixture was established in which partially purified rat liver phosphatidylinositol exchange proteins sustain a maximal rate of phosphatidylinositol transfer from rat pancreatic microsomes to liposomes. Determination of the transfer kinetics shows (1) that pancreatic microsomal phosphatidylinositol is partitioned approximately equally between a non-exchangeable and a single exchangeable pool and (2) that cholinergic stimulation does not significantly change the relative sizes of the two pools nor the exchange half-life of the latter pool. 相似文献
66.
Selective inhibition of isoprenylation of 21-26-kDa proteins by the anticarcinogen d-limonene and its metabolites 总被引:6,自引:0,他引:6
P L Crowell R R Chang Z B Ren C E Elson M N Gould 《The Journal of biological chemistry》1991,266(26):17679-17685
Limonene has chemotherapeutic activity against chemically induced rat mammary carcinomas, many of which contain activated ras genes. Given the recent discovery of the post-translational modification of p21ras and other cell growth-associated proteins by intermediates in the mevalonic acid pathway, and the common biochemical origins of limonene and these isoprene products, we investigated the effect of limonene on protein isoprenylation. NIH3T3 and human mammary epithelial cells were incubated with lovastatin and [2-14C]mevalonolactone in the absence and presence of limonene. Labeled proteins were then subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Limonene inhibited isoprenylation of a class of cellular proteins of 21-26 kDa, including p21ras and possibly other small GTP-binding proteins, in a dose-dependent manner in both cell lines. In contrast, limonene did not affect the isoprenylation of several other proteins, including nuclear lamins. Limonene is metabolized extensively in vivo but not in cultured cells. The two major rat serum metabolites of limonene, perillic acid and dihydroperillic acid, were more potent than limonene in the inhibition of isoprenylation. These results demonstrate that limonene selectively inhibits isoprenylation of 21-26-kDa proteins at a point in the mevalonic acid pathway distal to 3-hydroxy-3-methylglutaryl coenzyme A reductase, and they provide a plausible explanation for its chemotherapeutic activity. Inhibition of isoprenylation of proteins such as p21ras and other small GTP-binding proteins would alter their intracellular localization and, hence, disrupt their biological activity. 相似文献
67.
Evolutionary conservation of a microbody targeting signal that targets proteins to peroxisomes, glyoxysomes, and glycosomes. 总被引:19,自引:8,他引:11
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G A Keller S Krisans S J Gould J M Sommer C C Wang W Schliebs W Kunau S Brody S Subramani 《The Journal of cell biology》1991,114(5):893-904
Peroxisomes, glyoxysomes, glycosomes, and hydrogenosomes have each been classified as microbodies, i.e., subcellular organelles with an electron-dense matrix that is bound by a single membrane. We investigated whether these organelles might share a common evolutionary origin by asking if targeting signals used for translocation of proteins into these microbodies are related. A peroxisomal targeting signal (PTS) consisting of the COOH-terminal tripeptide serine-lysine-leucine-COOH has been identified in a number of peroxisomal proteins (Gould, S.J., G.-A. Keller, N. Hosken, J. Wilkinson, and S. Subramani. 1989. J. Cell Biol. 108:1657-1664). Antibodies raised to a peptide ending in this sequence (SKL-COOH) recognize a number of peroxisomal proteins. Immunocryoelectron microscopy experiments using this anti-SKL antibody revealed the presence of proteins containing the PTS within glyoxysomes of cells from Pichia pastoris, germinating castor bean seeds, and Neurospora crassa, as well as within the glycosomes of Trypanosoma brucei. Western blot analysis of purified organelle fractions revealed the presence of many proteins containing this PTS in both glyoxysomes and glycosomes. These results indicate that at least one of the signals, and therefore the mechanism, for protein translocation into peroxisomes, glyoxysomes, and glycosomes has been conserved, lending support to a common evolutionary origin for these microbodies. Hydrogenosomes, the fourth type of microbody, did not contain proteins that cross-reacted with the anti-PTS antibody, suggesting that this organelle is unrelated to microbodies. 相似文献
68.
Dina Zand Jeffrey Hammer Robert Gould Richard Quarles 《Journal of neurochemistry》1991,57(3):1076-1079
The major 24- and 28-kDa glycoproteins in shark PNS and CNS myelin express high levels of the adhesion-associated HNK-1/L2 carbohydrate epitope. The 28-kDa protein, but not the 24-kDa protein, cross-reacts strongly with one of two anti-bovine P0 antisera not previously tested against fish myelin proteins. Shark PNS and CNS myelin also contains smaller amounts of high-molecular-weight HNK-1-positive proteins, including a prominent broad band in the 65-85-kDa range. Although myelin-associated glycoprotein (MAG) is well known to react with HNK-1 in some mammals, monoclonal and polyclonal anti-MAG antibodies did not react with the high-molecular-weight HNK-1-positive material in shark myelin, a result suggesting that it is not a MAG-like protein. The high expression of the HNK-1/L2 epitope in glycoproteins of shark myelin, including the major P0-related ones, suggests that this adhesion-related carbohydrate structure may have had an important role in the molecular evolution of the myelinating process. 相似文献
69.
Regulation of cdc2 activity in Schizosaccharomyces pombe: the role of phosphorylation. 总被引:9,自引:0,他引:9
The cdc2 protein kinase, first identified as a cell cycle gene required for transition into the S- and M-phases of budding and fission yeast, has been shown to act as a key component in the regulation of the eukaryotic cell cycle. The periodic activation of cdc2 kinase, which is required for entry into M-phase, is regulated by subunit association with cyclin B, the cdc25, wee1, mik1 gene products and differential phosphorylation of the cdc2 protein. Phosphorylation at Tyr 15 inhibits activation of the cdc2/cdc13 complex whereas phosphorylation of Thr 167 is required for kinase activity. 相似文献
70.
Expression of GLUT-4 and insulin receptor mRNAs was investigated in rat skeletal muscle by Northern hybridization. GLUT-4 mRNA was barely detectable in foetal muscle, was expressed at low levels by 1-8 days and at 2-3-fold higher levels during and after weaning (18-40 days). In contrast there was little change in insulin receptor mRNA levels prior to weaning and a reduction in mRNA abundance between 18 and 40 days. Weaning rats on to a diet rich in fat prevented the increase in GLUT-4 abundance seen between 15 and 29 days in animals weaned on a high-carbohydrate diet. 相似文献