ACTION POTENTIAL MODIFICATIONS IN RAT MYOCARDIAL CELLS DURING VITAMIN A DEFICIENCY

¹ Institute of Human Physiology of the University of Pavia, Pavia (Italy)

Ventricular cell action potentials were measured in situ using intracellular microelectrodes in the hearts of vitamin A-deficient rats, both at the spontaneous heart rate and at rates increased to various higher levels. The changes found indicate that a lack of vitamin A in the tissue may modify the ion permeability underlying cardiac electrogenesis, without affecting cardiac energetic metabolism. Results are discussed in the light of recent theories that vitamin A may stabilize the structure of cell membranes and control their permeability.

Note:

This work was supported in part by a grant from Consiglio Nazionale delle Ricerche, Rome.

We wish to thank Professor G. Rapuzzi for invaluable advice and criticism of the manuscript.

We are most grateful to Prodotti Roche of Milan for a generous supply of ‘Arovit’.