“…It has been proposed from the experiments in rats that even low levels of Pb 2+ interfere with the contractile proteins of the heart and their contraction cycle (Katsnelson et al, 2020;Silva et al, 2015). More recent reports also found a negative inotropic of the Pb 2+ exposome (Klinova et al, 2020;Protsenko et al, 2018Protsenko et al, , 2019. However, some reports maintain that Pb 2+ has a positive inotropic effect in rats (Fioresi et al, 2014).…”