Table 1: Pharmacologic enzyme inhibitors.

Inhibitor Specificity Route Reference L-NAME Nonselective NOS Oral [20, 42, 43] NOHA Arginase Inhaled [39, 44, 45] nor-NOHA Arginase Inhaled, intraperitoneal [19, 38, 42, 46, 47] L-NMMA Arginase Inhaled [48] ABH Arginase Inhaled [49] BEC Arginase Oropharyngeal aspiration [50]

List of abbreviations: N (G-) nitro-L-arginine methyl ester (L-NAME), nitric oxide synthase (NOS), N-hydroxy-L-arginine (NOHA), N-hydroxy-nor-L-arginine (nor-NOHA), NG-monomethyl-L-arginine (L-NMMA), 2(S)-amino-6-boronohexanoic acid (ABH), S-(2-boronoethyl)-l-cysteine (BEC).