Elettrogenesi cardiaca e piridossina

Ceriani, Teresa ; Sciorelli, Gianalfredo ; Ventura, Ulderico ; Rindi, Gianguido

Atti della Accademia nazionale dei Lincei. Rendiconti della Classe di scienze fisiche, matematiche e naturali, Série 8, Tome 55 (1973) no. 1-2, pp. 127-131

Résumé

Pyridoxine deficiency was induced in the rat with a free-pyridoxine diet and assayed by the determination of total vitam in B6 content in heart, liver and gastrocnemius muscle. Ventricular myocardial cell action potentials were measured in situ in the hearts both of pyridoxine-deficient rats and of pyridoxine-supplemented rats. Intracellular action potentials were recorded at spontaneous frequency and at frequencies increased to higher levels. Pyridoxine deficiency caused a noticeable bradycardia and lowered the rates of depolarization and repolarization phases of ventricular action potentials thus lengthening their duration. The modifications of ventricular action potentials and frequency were largely restored by pyridoxine administration. The mechanisms by which pyridoxine deficiency seems to affect cardiac electrogenesis are pointed out.