ISSN:
1432-2013
Keywords:
Heart Muscle
;
Longitudinal Resistance
;
Sucrose
;
Calcium
;
Longitudinal Ion Distribution
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Trabecular muscle bundles from sheep and calf hearts were exposed to isosmotic sucrose solution in a single sucrose gap arrangement. Inside longitudinal specific resistanceR i , calculated from recordings of the inside and outside action potentials across the gap and the total longitudinal resistance in the mid-interpolar region, increase tenfold from an initial value of 463 Ω cm during 4 h of sucrose perfusion. Upon re-perfusion with Tyrode for 8–10 hR i decreased to 1000 Ω cm. The marked increase ofR i was prevented by addition of 10−4 M CaCl2 to the sucrose solution. The inside and outside action potentials across the gap became distorted whenR i reached high values. Longitudinal distribution of sodium and potassium in a number of trabeculae was determined with activation analysis. These experiments revealed considerable mixing between sodium and sucrose near the sucrose-Tyrode junction. The longitudinal distribution of potassium suggests that loss of ions from the cells cannot account for the increase ofR i .
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00586334
Permalink
