Isolated, isometrically contracting cat papillary muscles were used to evaluate the inotropic interactions of lactic acidosis, hyperbaric acidosis, and lactate ion with hypertonic mannitol. These studies have documented that both lactic acidosis (pH < 7.0) and lactate ion at a normal pH inhibit the inotropic effect of hyperosmotic mannitol in vitro. In contrast, hypercarbic acidosis does not prevent the inotropic effect of mannitol. Inhibition by lactic acid of mannitol's effects on contractility persists in the presence of beta receptor blockade. The results suggest that inhibition by severe lactic acidosis of the direct inotropic effect of hyperosmolality in isolated cardiac muscle is mediated by lactate ion rather than acidosis per se.
|Original language||English (US)|
|Title of host publication||American Journal of Physiology|
|Number of pages||5|
|State||Published - 1976|
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