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1.
Summary The muscle enzyme calpain II, in contrast to muscle calpain I, was markedly inhibited by millimolar concentrations of the polyamines spermine and spermidine. These compounds and the calpain inhibitor calpastatin had synergistic inhibitory effects on calpain II. These results suggest that the polyamines may have possible regulatory effects on the in vivo activity of calpain II enzymes. 相似文献
2.
Y. Nagao S. Takao E. Fujita C. Murayama T. Mori T. Asao T. Suzue 《Cellular and molecular life sciences : CMLS》1983,39(10):1116-1118
Summary New type hypoxic cell sensitizers, N1, N10-bis(4-nitrobenzoyl)spermidine (1) and N1,N14-bis(4-nitrobenzoyl)-spermine (2), have been developed. These compounds were shown to be more effective radiosensitizers to hypoxic cells than misonidazole (3). 相似文献
3.
The polyamine putrescine might be formed via a degradation (catalyzed by spermidine/spermine N1-acetyltransferase, SSAT) of the higher polyamines spermidine and spermine to putrescine. The involvement of different intracellular signal pathways in the regulation of putrescine formation was studied in explants and in cultured cells of rat parotid glands by using receptor agonists that activate separate second messenger systems, and measuring their effects on the concentrations of putrescine, spermidine and spermine and on the SSAT activity. The -adrenoceptor agonist isoprenaline, which is an activator of cAMP formation, increased the putrescine concentration and stimulated the SSAT activity. Pilocarpine, a drug that activates the muscarinic receptors and thereby enhances the phosphoinositide turnover, had no effect on either the polyamine concentrations or on the SSAT activity. Epidermal growth factor (EGF), which induces activation of a protein tyrosine kinase, had no effect on the polyamine concentrations or on the SSAT activity. The adenylate cyclase activator forskolin increased the glandular levels of putrescine. Taken together, these findings suggest that increases in putrescine concentration in cultured rat parotid gland cells are accompanied by accumulation of cAMP. 相似文献
4.
In vitro studies showed that the flavonoid aglycones apigenin, luteolin and kaempferol inhibited the hyaluronidase activity of five different venoms dose-dependently. They were also able to delay the venom action when injected into mice. Naringenin, catechin and flavonoid glycosides had no effect. The flavonoids with unsubstituted hydroxyl groups at C-positions 5, 7 and 4′, a double bond between carbons 2 and 3, as well as a ketone group at position 4, exhibited potent inhibitory actions on the venom hyaluronidases. 相似文献
5.
In vitro studies showed that the flavonoid aglycones apigenin, luteolin and kaempferol inhibited the hyaluronidase activity of five different venoms dose-dependently. They were also able to delay the venom action when injected into mice. Naringenin, catechin and flavonoid glycosides had no effect. The flavonoids with unsubstituted hydroxyl groups at C-positions 5, 7 and 4', a double bond between carbons 2 and 3, as well as a ketone group at position 4, exhibited potent inhibitory actions on the venom hyaluronidases. 相似文献
6.
M. A. Friedman 《Cellular and molecular life sciences : CMLS》1974,30(8):857-859
Zusammenfassung Nachweis, dass Nitrosarcosin im Gegensatz zu Dimethyl- und Dibutylnitrosamin die nichtfunktionelle Oxidase in der Mäuseleber hemmt.
This work was supported by N.I.E.H.S. grant No. ES 00713.
We are indebted to the technical help of Ms.Heather McClanahan. 相似文献
This work was supported by N.I.E.H.S. grant No. ES 00713.
We are indebted to the technical help of Ms.Heather McClanahan. 相似文献
7.
L Ferland C Auclair F Labrie G Azadian-Boulanger J P Raynaud 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(14):1113-1116
The administration of LHRH or of its analog [D-Ala6, des-Gly-NH10(2)] LHRH ethylamide to the female rat on day 10 of gestation resulted in termination of pregnancy and in a marked decrease in ovarian LH receptors and plasma progesterone level. Asingle injection of either compound during diestrus I also led to a decrease in LH receptors. These data demonstrate the high sensitivity of the control of ovarian LH receptors by circulating gonadotrophins and suggest that the contraceptive action of pre- and postcoitally administered LHRH is mediated by negative control of LH receptors. 相似文献
8.
Inhibitory effects of phenolic compounds on CCl4-induced microsomal lipid peroxidation 总被引:2,自引:0,他引:2
The antiperoxidative effects of 35 phenolic compounds, most of them belonging to the flavonoid class, were investigated using CCl4-induced peroxidation of rat liver microsomes. This system was rather insensitive to gallic acid, methyl gallate and ellagic acid. Nevertheless it was inhibited by flavonoids and structure/activity relationships were established. The most potent compounds were gardenin D, luteolin, apigenin (flavones), datiscetin, morin, galangin (flavonols), eriodictyol (flavanone), amentoflavone (biflavone) and the reference compound, (+)-catechin. The natural polymethoxyflavone gardenin D has shown a potency comparable to that of (+)-catechin and higher than that of silybin. Thus, it may be considered as a new type of natural antioxidant with potential therapeutical applications. 相似文献
9.
A. Portela R. J. Pérez R. Nallar J. C. Pérez P. Stewart J. A. Vicente P. Lonchampt 《Cellular and molecular life sciences : CMLS》1969,25(2):143-144
Résumé Dans un muscle non dénervé, la choline provoque une dépolarisation permanente en présence de «Cs-Ringer» et transitoire en présence de «K-Ringer». La dénervation augmente la sensibilité de la membrane musculaire à la choline. Mais dans ce cas, le «Cs-Ringer» donne une réponse transitoire à la choline, semblable à celle obtenue avec le «K-Ringer». 相似文献
10.
C Auclair L Ferland L Cusan P A Kelly F Labrie G Azadian-Boulanger J P Raynaud 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(18):1305-1307
A single injection of LHRH to the adult male rat, as of its analog [D-Ala6, des-Gly-NH102] LHRH ethylamide, resulted in a marked decrease in LH receptors in the tests. Plasma testosterone level and the weight of the seminal vesicles and prostate were also decreased after treatment. These data demonstrate that LHRH can decrease the sensitivity of LH receptors and testicular function in the rat. 相似文献
11.
Summary The antiperoxidative effects of 35 phenolic compounds, most of them belonging to the flavonoid class, were investigated using CCl4-induced peroxidation of rat liver microsomes. This system was rather insensitive to gallic acid, methyl gallate and ellagic acid. Nevertheless it was inhibited by flavonoids and structure/activity relationships were established. The most potent compounds were gardenin D, luteolin, apigenin (flavones), datiscetin, morin, galangin (flavonols), eriodictyol (flavanone), amentoflavone (biflavone) and the reference compound, (+)-catechin. The natural polymethoxyflavone gardenin D has shown a potency comparable to that of (+)-catechin and higher than that of silybin. Thus, it may be considered as a new type of natural antioxidant with potential therapeutical applications. 相似文献
12.
J. del Castillo W. C. de Mello T. Morales 《Cellular and molecular life sciences : CMLS》1964,20(3):141-143
Zusammenfassung Die somatische Muskulatur vonAscaris lumbricoides wird durch-Aminobuttersäure in Konzentrationen von 10–6-10–5
M völlig gehemmt. Eine hnliche Hemmung wird durch Piperazin (10–3
M) erzielt. Beide Substanzen steigern die Cl-Permeabilität der Muskelmembran.
On leave of absence from the Instituto de Biofísica, Universidade do Brazil, Rio de Janeiro (Brazil). 相似文献
On leave of absence from the Instituto de Biofísica, Universidade do Brazil, Rio de Janeiro (Brazil). 相似文献
13.
G. V. Shah A. R. Sheth P. P. Mugatwala Shanta S. Rao 《Cellular and molecular life sciences : CMLS》1975,31(6):631-632
Zusammenfassung Zusätze physiologischer Sperminkonzentrationen (2–14 mM) zu menschlichen Spermiensuspensionen bewirken eine Steigerung der Adenylcyclase-Aktivität, wie sie durch die vermehrte Bildung von cAMP aus ATP angezeigt wird. 相似文献
14.
Zusammenfassung Die kontraktile Reaktion des isolierten Meerschweinchen-Ileums auf Angiotensin II variierte direkt mit der Natriumkonzentration der Nährflüssigkeit, nicht aber bei ACh; Atropin (10–6 g/ml) reduzierte die Wirkung auf Angiotensin um 60–70% und hob die Wirkung auf äquivalente Mengen von ACh auf. In atropinhaltiger Ringerlösung potenzierte ein hoher Natriumgehalt (+ 30 meq./l) die Reaktion auf Angiotensin zehnfach. 相似文献
15.
Koleva M Kappler R Vogler M Herwig A Fulda S Hahn H 《Cellular and molecular life sciences : CMLS》2005,62(16):1863-1870
Muscle satellite cells are believed to form a stable, self-renewing pool of stem cells in adult muscle where they function in tissue growth and repair. A regulatory disruption of growth and differentiation of these cells is assumed to result in tumor formation. Here we provide for the first time evidence that sonic hedgehog (Shh) regulates the cell fate of adult muscle satellite cells in mammals. Shh promotes cell division of satellite cells (and of the related model C2C12 cells) and prevents their differentiation into multinucleated myotubes. In addition, Shh inhibits caspase-3 activation and apoptosis induced by serum deprivation. These effects of Shh are reversed by simultaneous administration of cyclopamine, a specific inhibitor of the Shh pathway. Taken together, Shh acts as a proliferation and survival factor of satellite cells in the adult muscle. Our results support the hypothesis of the rhabdomyosarcoma origin from satellite cells and suggest a role for Shh in this process.Received 23 February 2005; received after revision 2 May 2005; accepted 9 June 2005 相似文献
16.
Summary The present results, using isolated rat aortic strips and portal vein segments, demonstrate that ethanol, depending upon concentration, can either enhance or attenuate the contractile actions of PGF2 on at least 2 different types of vascular smooth muscle. At the very least, the present findings question the use of ethanol as a solvent when investigating the contractile actions of PG molecules on smooth muscles.Supported by NIH grant No. HL-18015 and NIMH grant No. MH-26236. The authors are indebted to Dr.John E. Pike and Dr.John Babcock of the Upjohn Company for generously providing us with the PGF2 used in this study. 相似文献
17.
Studies of the last two decades have demonstrated that sphingolipids are important signalling molecules exerting key roles
in the control of fundamental biological processes including proliferation, differentiation, motility and survival. Here we
review the role of bioactive sphingolipids such as ceramide, sphingosine, sphingosine 1-phosphate, ganglioside GM3, in the
regulation of skeletal muscle biology. The emerging picture is in favour of a complex role of these molecules, which appear
implicated in the activation of muscle resident stem cells, their proliferation and differentiation, finalized at skeletal
muscle regeneration. Moreover, they are involved in the regulation of contractile properties, tissue responsiveness to insulin
and muscle fiber trophism. Hopefully, this article will provide a framework for future investigation into the field, aimed
at establishing whether altered sphingolipid metabolism is implicated in the onset of skeletal muscle diseases and identifying
new pharmacological targets for the therapy of multiple illnesses, including muscular dystrophies and diabetes.
Received 30 April 2008; received after revision 19 June 2008; accepted 14 July 2008 相似文献
18.
19.
S. Lund 《Cellular and molecular life sciences : CMLS》1980,36(12):1398-1398
Summary Vibration of the dorsal neck muscles in man induces falling reactions, walking and marche en étoile, probably by muscle afferent activation. It can be used as a reproducible error signal in analyzing the interaction between neck muscle proprioception and vestibular as well as ocular motor systems. These interactions are important for posture and coordinated head-eye movements. 相似文献
20.
Résumé L'addition de spermine au microsomes du foie de rats femelles modifie leK
m du système enzymatique qui transforme 1'estradiol en 2-hydroxyestradiol et aussi en des produits aqueux. La nouvelle valeur resemble à celle qu'ont trouve avec des rats mâles, mais leV
max de la réaction reste inchangé. L'action de la spermine dans ce système est discutée. 相似文献