Hydrogen sulfide production in response to 5 X [10.sup.-3] M 5HT was measured in gills exposed to either 1 mM propargylglycine (PAG), an inhibitor of cystathionine-[gamma]-lyase, or 1 mM aminooxyacetic acid (AOAA), an inhibitor of cystathionine-[beta]-synthase.
Abbreviations: AOAA, aminooxyacetic acid; ANOVA, analysis of variance; ASW, artificial seawater; CBS, cystathionine-[beta]-synthase; cGMP: 3'-5' cyclic quanosine monophosphate; CO, carbon monoxide; CSE, cystathionine-[gamma]-lyase; DMSO, dimethyl sulfoxide; DTT, dithiothreitol, 5HT, 5-hydroxytryptamine; [H.sub.2]S, hydrogen sulfide; NaHS, sodium hydrosulfide; NO, nitric oxide; NOS, nitric oxide synthase; ODQ, oxadiasoloquinoxalin; p, probability; PAG, propargylglycine; PK-G, protein kinase-G; Rp-8-CPT-cGMPS, (Rp-8-[(4-chlorophenyl)thio]-guanosine 3',5'-cyclic monophosphothioate triethylamine); sGC, soluble guanylate cyclase; SNP, sodium nitroprusside; YC-1, 3-(5'-Hydroxymethyl-2'-furyl)-1-benzyl indazole.