ACE and hypertensive disorder: In vivo and in vitro studies with animals have shown that chronic lead exposure causes hypertension and cardiovascular disease by altering the renin-angiotensin system due to elevated ACE activity [14]–[16], inhibition of Na+, K+- ATPase [17], induction of oxidative stress, reduction of nitric oxide bioavailability [1], [18]–[21] and depletion of antioxidant reserves [22].