{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T06:25:41Z","timestamp":1779344741052,"version":"3.51.4"},"reference-count":62,"publisher":"Wiley","issue":"8","license":[{"start":{"date-parts":[[2009,2,11]],"date-time":"2009-02-11T00:00:00Z","timestamp":1234310400000},"content-version":"vor","delay-in-days":4212,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["bpspubs.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["British J Pharmacology"],"published-print":{"date-parts":[[1997,8]]},"abstract":"<jats:p>\n<jats:list list-type=\"explicit-label\">\n<jats:list-item><jats:p>The effects of the voltage\u2010dependent calcium channel (VDCC) blockers \u03c9\u2010agatoxin IVA (\u03c9\u2010AgaIVA), \u03c9\u2010conotoxin GVIA (\u03c9\u2010CgTx), \u03c9\u2010conotoxin MVIIC (\u03c9\u2010MVIIC) and \u03c9\u2010conotoxin MVIID (\u03c9\u2010MVIID) were evaluated on transmitter release in the mouse diaphragm preparation. The effects of \u03c9\u2010AgaIVA and \u03c9\u2010MVIIC were also evaluated on the perineurial calcium and calcium\u2010dependent potassium currents, <jats:italic>I<\/jats:italic><jats:sub>Ca<\/jats:sub> and <jats:italic>I<\/jats:italic><jats:sub>K(Ca)<\/jats:sub>, respectively, in the mouse levator auris preparation.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>The P\u2010 and Q\u2010type VDCC blocker \u03c9\u2010AgaIVA (100\u2003n<jats:sc>M<\/jats:sc>) and P\u2010 Q\u2010 and N\u2010type channel blockers \u03c9\u2010MVIIC (1\u2003\u03bc<jats:sc>M<\/jats:sc>) and \u03c9\u2010MVIID (3\u2003\u03bc<jats:sc>M<\/jats:sc>) strongly reduced transmitter release (&gt;80\u201390% blockade) whereas the selective N\u2010type channel blocker \u03c9\u2010CgTx (5\u2003\u03bc<jats:sc>M<\/jats:sc>) was ineffective.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>The process of release was much more sensitive to \u03c9\u2010MVIIC (IC<jats:sub>50<\/jats:sub>=39\u2003n<jats:sc>M<\/jats:sc>) than to \u03c9\u2010MVIID (IC<jats:sub>50<\/jats:sub>=1.4\u2003\u03bc<jats:sc>M<\/jats:sc>). After almost completely blocking transmitter release (quantal content \u223c0.3% of its control value) with 3\u2003\u03bc<jats:sc>M<\/jats:sc>\u03c9\u2010MVIIC, elevating the external [Ca<jats:sup>2+<\/jats:sup>] from 2 to 10\u2003m<jats:sc>M<\/jats:sc> induced an increase of \u223c20 fold on the quantal content of the endplate potential (e.p.p.) (from 0.2\u00b10.04 to 4.8\u00b11.4).<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>Nerve\u2010evoked transmitter release in a low Ca<jats:sup>2+<\/jats:sup>\u2010high Mg<jats:sup>2+<\/jats:sup> medium (low release probability, quantal content = 2\u00b10.1) had the same sensitivity to \u03c9\u2010AgaIVA (IC<jats:sub>50<\/jats:sub>=16.8\u2003n<jats:sc>M<\/jats:sc>) as that in normal saline solutions. In addition, K<jats:sup>+<\/jats:sup>\u2010evoked transmitter release was also highly sensitive to the action of this toxin (IC<jats:sub>50<\/jats:sub>=11.5\u2003n<jats:sc>M<\/jats:sc>; 100\u2003n<jats:sc>M<\/jats:sc> &gt;95% blockade). The action of \u03c9\u2010AgaIVA on transmitter release could be reversed by toxin washout if the experiments were carried out at 31\u201333\u00b0C. Conversely, the effect of \u03c9\u2010AgaIVA persisted even after two hours of toxin washout at room temperature.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>Both the calcium and calcium\u2010dependent potassium presynaptic currents, <jats:italic>I<\/jats:italic><jats:sub>Ca<\/jats:sub> and <jats:italic>I<\/jats:italic><jats:sub>K(Ca)<\/jats:sub>, respectively, were highly sensitive to low concentrations (10\u201330\u2003n<jats:sc>M<\/jats:sc>) of \u03c9\u2010AgaIVA. The <jats:italic>I<\/jats:italic><jats:sub>Ca<\/jats:sub> and the <jats:italic>I<\/jats:italic><jats:sub>K(Ca)<\/jats:sub> were also strongly reduced by 1\u2003\u03bc<jats:sc>M<\/jats:sc>\u03c9\u2010MVIIC. The most marked difference between the action of these two toxins was the long incubation times required to achieve maximal effects with \u03c9\u2010MVIIC.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>In summary these results provide more evidence that synaptic transmission at the mammalian neuromuscular junction is mediated by Ca<jats:sup>2+<\/jats:sup> entry through P\u2010 and\/or Q\u2010type calcium channels.<\/jats:p><\/jats:list-item>\n<\/jats:list>\n<\/jats:p><jats:p> <jats:italic>British Journal of Pharmacology<\/jats:italic> (1997) <jats:bold>121<\/jats:bold>, 1531\u20131540; doi:<jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"doi\" xlink:href=\"10.1038\/sj.bjp.0701290\">10.1038\/sj.bjp.0701290<\/jats:ext-link><\/jats:p>","DOI":"10.1038\/sj.bjp.0701290","type":"journal-article","created":{"date-parts":[[2006,8,25]],"date-time":"2006-08-25T17:13:48Z","timestamp":1156526028000},"page":"1531-1540","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":48,"title":["Effects of Ca<sup>2+<\/sup> channel blocker neurotoxins on transmitter release and presynaptic currents at the mouse neuromuscular junction"],"prefix":"10.1111","volume":"121","author":[{"given":"Eleonora","family":"Katz","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dar\u00edo A.","family":"Protti","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pablo A.","family":"Ferro","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marcelo D.","family":"Rosato Siri","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Osvaldo D.","family":"Uchitel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2009,2,11]]},"reference":[{"key":"e_1_2_6_2_1","first-page":"2544","article-title":"Pharmacological characterization of the voltage\u2010dependent Ca2+ channels present in synaptosomes from rat and chicken central nervous system","volume":"65","author":"Alvarez\u2010Maubecin V. A.","year":"1995","journal-title":"J. Neurochem."},{"key":"e_1_2_6_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(87)90125-X"},{"key":"e_1_2_6_4_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1476-5381.1988.tb11772.x"},{"key":"e_1_2_6_5_1","first-page":"672","article-title":"Dihydropyridine\u2010sensitive and \u2010insensitive components of acetylcholine release from rat motor nerve terminals","volume":"251","author":"Atchinson W. D.","year":"1989","journal-title":"J. Pharmacol. Exp. Ther."},{"key":"e_1_2_6_6_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1986.sp016347"},{"key":"e_1_2_6_7_1","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.ph.51.030189.002055"},{"key":"e_1_2_6_8_1","first-page":"248","article-title":"Differential blockade of voltage\u2010sensitive calcium channels at the mouse neuromuscular junction by novel \u03c9\u2010conopeptides and \u03c9\u2010Agatoxin\u2010IVA","volume":"273","author":"Bowersox S. S.","year":"1995","journal-title":"J. Pharmacol. Exp. Ther."},{"key":"e_1_2_6_9_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1982.sp014472"},{"key":"e_1_2_6_10_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1967.sp008367"},{"key":"e_1_2_6_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/0166-2236(95)80030-6"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/0896-6273(92)90221-X"},{"key":"e_1_2_6_13_1","first-page":"314","volume-title":"Phylogenetic and Biochemical Perspectives. Biochemical and Molecular Biology of Fishes","author":"Hochachka P. W.","year":"1991"},{"key":"e_1_2_6_14_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1995.sp020517"},{"key":"e_1_2_6_15_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1971.sp009542"},{"key":"e_1_2_6_16_1","volume-title":"Electrophysiological Analysis of Synaptic Transmission","author":"Hubbard J. I.","year":"1969"},{"key":"e_1_2_6_17_1","volume-title":"The Release of Neural Transmitter Substances","author":"Katz B.","year":"1969"},{"key":"e_1_2_6_18_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1995.sp020845"},{"key":"e_1_2_6_19_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1996.sp021800"},{"key":"e_1_2_6_20_1","doi-asserted-by":"publisher","DOI":"10.1038\/308282a0"},{"key":"e_1_2_6_21_1","doi-asserted-by":"publisher","DOI":"10.1006\/mcne.1994.1026"},{"key":"e_1_2_6_22_1","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(95)11768-R"},{"key":"e_1_2_6_23_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.73.8.2918"},{"key":"e_1_2_6_24_1","doi-asserted-by":"publisher","DOI":"10.1016\/0166-2236(92)90053-B"},{"key":"e_1_2_6_25_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.86.5.1689"},{"key":"e_1_2_6_26_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1985.sp015876"},{"key":"e_1_2_6_27_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1985.sp015877"},{"key":"e_1_2_6_28_1","doi-asserted-by":"publisher","DOI":"10.1016\/0006-8993(89)91348-6"},{"key":"e_1_2_6_29_1","doi-asserted-by":"publisher","DOI":"10.1152\/physrev.1966.46.1.51"},{"key":"e_1_2_6_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/0028-3908(95)00130-X"},{"key":"e_1_2_6_31_1","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.16-08-02612.1996"},{"key":"e_1_2_6_32_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1981.sp013586"},{"key":"e_1_2_6_33_1","doi-asserted-by":"publisher","DOI":"10.1016\/0896-6273(95)90155-8"},{"key":"e_1_2_6_34_1","doi-asserted-by":"publisher","DOI":"10.1016\/0896-6273(92)90223-Z"},{"key":"e_1_2_6_35_1","doi-asserted-by":"publisher","DOI":"10.1038\/355827a0"},{"key":"e_1_2_6_36_1","doi-asserted-by":"publisher","DOI":"10.1016\/0028-3908(93)90008-Q"},{"key":"e_1_2_6_37_1","doi-asserted-by":"publisher","DOI":"10.1038\/316440a0"},{"key":"e_1_2_6_38_1","doi-asserted-by":"publisher","DOI":"10.1021\/bi00317a001"},{"key":"e_1_2_6_39_1","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.bi.63.070194.004135"},{"key":"e_1_2_6_40_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF00586682"},{"key":"e_1_2_6_41_1","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.46.5.1391"},{"key":"e_1_2_6_42_1","doi-asserted-by":"publisher","DOI":"10.1016\/0006-8993(91)90156-P"},{"key":"e_1_2_6_43_1","doi-asserted-by":"publisher","DOI":"10.1097\/00001756-199312000-00039"},{"key":"e_1_2_6_44_1","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.15-04-02995.1995"},{"key":"e_1_2_6_45_1","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.12-01-00297.1992"},{"key":"e_1_2_6_46_1","doi-asserted-by":"publisher","DOI":"10.1016\/0896-6273(93)90076-4"},{"key":"e_1_2_6_47_1","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3940(94)90078-7"},{"key":"e_1_2_6_48_1","first-page":"235","article-title":"Effects of synthetic \u03c9\u2010conotoxin, a new type Ca2+ channel antagonist, on frog and mouse neuromuscular transmission","volume":"141","author":"Sano K","year":"1987","journal-title":"J. Pharmacol."},{"key":"e_1_2_6_49_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.91.22.10576"},{"key":"e_1_2_6_50_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF01370157"},{"key":"e_1_2_6_51_1","doi-asserted-by":"publisher","DOI":"10.1038\/366156a0"},{"key":"e_1_2_6_52_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.1357749"},{"key":"e_1_2_6_53_1","doi-asserted-by":"publisher","DOI":"10.1016\/0028-3908(95)00133-Q"},{"key":"e_1_2_6_54_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.89.8.3330"},{"key":"e_1_2_6_55_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1476-5381.1995.tb13377.x"},{"key":"e_1_2_6_56_1","doi-asserted-by":"publisher","DOI":"10.1016\/0014-2999(95)00133-6"},{"key":"e_1_2_6_57_1","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.15-10-06403.1995"},{"key":"e_1_2_6_58_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.7832825"},{"key":"e_1_2_6_59_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.266.5186.830"},{"key":"e_1_2_6_60_1","doi-asserted-by":"publisher","DOI":"10.1016\/0028-3908(93)90007-P"},{"key":"e_1_2_6_61_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1476-5381.1996.tb15676.x"},{"key":"e_1_2_6_62_1","first-page":"1229","article-title":"Effects of \u03c9\u2010Agatoxin\u2010IVA and \u03c9\u2010Conotoxin\u2010MVIIC on perineurial Ca++ and Ca ++ \u2010activated K+ currents of mouse motor nerve terminals","volume":"279","author":"Xu Y\u2010F.","year":"1996","journal-title":"J. Pharmacol. Exp. Ther."},{"key":"e_1_2_6_63_1","doi-asserted-by":"publisher","DOI":"10.1016\/0028-3908(93)90003-L"}],"container-title":["British Journal of Pharmacology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1038%2Fsj.bjp.0701290","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1038%2Fsj.bjp.0701290","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/bpspubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1038\/sj.bjp.0701290","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,27]],"date-time":"2023-10-27T19:46:01Z","timestamp":1698435961000},"score":1,"resource":{"primary":{"URL":"https:\/\/bpspubs.onlinelibrary.wiley.com\/doi\/10.1038\/sj.bjp.0701290"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1997,8]]},"references-count":62,"journal-issue":{"issue":"8","published-print":{"date-parts":[[1997,8]]}},"alternative-id":["10.1038\/sj.bjp.0701290"],"URL":"https:\/\/doi.org\/10.1038\/sj.bjp.0701290","archive":["Portico"],"relation":{},"ISSN":["0007-1188","1476-5381"],"issn-type":[{"value":"0007-1188","type":"print"},{"value":"1476-5381","type":"electronic"}],"subject":[],"published":{"date-parts":[[1997,8]]},"assertion":[{"value":"2009-02-11","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}