Abstract:
:The actions of various opioids were examined on calcium action potentials in the cell somata of guinea pig myenteric neurones and on the release of acetylcholine at synapses onto these cells. The opioids morphine, normorphine, and [D-Ala2, MePhe4, Met5(O)]enkephalin-ol caused membrane hyperpolarizations resulting from an increase in potassium conductance; opioids that are more selective agonists for the kappa receptor subtype (dynorphin, tifluadom, U50488H) did not. Conversely, calcium action potentials were depressed or abolished by the kappa opioids but were not affected by morphine and [D-Ala2, MePhe4, Met(O)5]enkephalin-ol. Both groups of opioids caused presynaptic inhibition of acetylcholine release in the myenteric plexus, depressing the amplitude of the fast excitatory postsynaptic potential. The presynaptic inhibition caused by [D-Ala2, MePhe4, Met(O)5]enkephalin-ol, morphine, and normorphine, but not that caused by the kappa opioids, was prevented by pretreatment with the selective mu site-directed irreversible antagonist beta-funaltrexamine. Furthermore, the presynaptic inhibitory action of morphine and [D-Ala2, MePhe4, Met(O)5]enkephalin-ol, but not that of the kappa-receptor agonists, was reversibly blocked by barium. The results suggest that presynaptic inhibition caused by mu receptor activation probably results from an increase in potassium conductance, whereas kappa-receptor agonists may depress the release of acetylcholine by directly reducing calcium entry into the nerve terminals.
journal_name
Proc Natl Acad Sci U S Aauthors
Cherubini E,North RAdoi
10.1073/pnas.82.6.1860subject
Has Abstractpub_date
1985-03-01 00:00:00pages
1860-3issue
6eissn
0027-8424issn
1091-6490journal_volume
82pub_type
杂志文章abstract::Spo11 and the Rad50-Mre11 complex have been indirectly implicated in processes associated with DNA replication. These proteins also have been shown to have early meiotic roles essential for the formation of a programmed DNA double-strand break known in Saccharomyces cerevisiae to initiate meiotic recombination. In bot...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.190346097
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abstract::Adult cardiomyocytes are irreversibly postmitotic but respond to a variety of stimuli by hypertrophic growth, which is associated with an increase in cell size and protein content, organization of sarcomeres, and activation of a fetal gene program. Recently, we described a novel cardiac helicase activated by MEF2 prot...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.261708699
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1994-09-13 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1992-05-01 00:00:00
abstract::The sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) is a P-type ATPase that transports Ca2+ from the cytosol into the sarco(endo)plasmic reticulum (SR/ER) lumen, driven by ATP. This primary transport activity depends on tight coupling between movements of the transmembrane helices forming the two Ca2+-binding sites a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2006-07-18 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.22.8497
更新日期:1988-11-01 00:00:00
abstract::The mannose receptor (MR) is an endocytic receptor involved in serum homeostasis and antigen presentation. Here, we identify the MR as a direct regulator of CD8(+) T-cell activity. We demonstrate that MR expression on dendritic cells (DCs) impaired T-cell cytotoxicity in vitro and in vivo. This regulatory effect of th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1989-05-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2001-04-24 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2012-03-20 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1988-09-01 00:00:00