HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ochi, R Search for Related Content PubMed PubMed Citation Articles by Ochi, R

1. Propagated action potentials were recorded in right ventricular papillary muscles from guinea-pig heart while exposed to Na-free, Ca-free and Mg-free solutions containing Mn. 2. When Na was totally replaced by 95 mM-Mn the overshoot was about 45 mV while the resting potential was about -90mV. 3. The overshoot of action potentials was increased by about 20-30 mV per tenfold increase of Mn concentration over the range of 2-50 mM. 4. Similar increases of overshoots with increasing of Mn concentration also occurred in the presence of 0-6 mM-Ca. Increasing of Ca from 5 to 20 mM had little influence on the overshoot but shortened the duration of the Mn-dependent action potential in the presence of 5 mM-MN. 5 Mn-dependent action potentials were not depressed by 3 X 10(5) M tetrodotoxin but by La. 6. These results suggest that Mn passes through the slow inward current channel to generate the action potential seen under the Na-free condition. 7. The overshoot and duration of the Mn-dependent action potential decreased with stimulation. At stimulus frequencies (Hz) of 0-5, 0-2, 0-1, 0-017 and 0-0033 the overshoot of action potential in 5 mM-Mn Tyrode decreased by 0-5-1 mV per an action potential. This depression of the action potential is explained by assuming intracellular accumulation of Mn.

This article has been cited by other articles:

				J.-S. Fan, Y. Yuan, and P. Palade FPL-64176 modifies pore properties of L-type Ca2+ channels Am J Physiol Cell Physiol, March 1, 2001; 280(3): C565 - C572. [Abstract] [Full Text] [PDF]