EDN1 and Hypertension: Arsenic exposure is also associated with hypertension [102], with proposed mechanisms including increased calcium sensitization and enhanced myosin light chain mediated vasoconstriction [79], arsenic-induced sympathetic hypersensitivity and beta-adrenoceptor stimulation [103], and enhanced expression of endothelin 1 (ET-1) messenger ribonucleic acid (mRNA) [104].