ISSN:
1432-2013
Keywords:
Patch clamp
;
Bufo marinus
;
Dihydropyridine
;
Bay K 8644
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Single-channel currents were recorded from two classes of Ca2+ channels in visceral smooth muscle cells isolated from the stomach of the toad, Bufo marinus: a class of small-conductance channels (approximately 11 pS) and a class of large-conductance channels (approximately 26 pS). Small-conductance channels were present in a majority of patches and gave rise to a slowly inactivating current (t1/2 ≈ 250 ms at 0 mV). Openings of large-conductance channels could be unequivocally resolved only in the presence of the dihydropyridine Ca2+ agonist Bay K 8644. Two subtypes of the large-conductance channels were found — those with a very slow rate of decay (〉 500 ms) and those with a faster one (〈 100ms). Large-conductance channels resemble L-type Ca2+ channels of other preparations. Small-conductance channels do not fit unambiguously into the other existing categories (i.e., N or T). Correspondence between single-channel and macroscopic Ca2+ currents is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00370463
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