Positive inotropic effect of some taurine-related compounds on guinea-pig ventricular strips perfused with low calcium medium.

Taurine exerts a positive inotropic effect at a low calcium concentration. Of the compounds chemically related to taurine only L-cysteic and 2-aminobenzenesulfonic acid mimic taurine action. Their effect is concentration-dependent and not linked to the restoration of taurine tissue concentration in guinea-pig ventricular strips. Our data demonstrate that: (1) carbon chain length between amino and sulfonic groups is a crucial factor in the development of activity. (2) Substitution of the sulfonic group with other acid functions such as the substitution of the primary amino group or the introduction of the -COOH group onto the beta-carbon brings about a lack of activity.