Fig. 5. Twenty-four hour production of H₂S by trout in the presence of no inhibitors (Control), the cystathionine -lyase inhibitor, D,L-propargylglycine (PPG; 20 mmol l^-1) or the cystathionine ß-synthase inhibitor, amino-oxyacetic acid (AOA; 1 mmol l^-1). Values are means ± s.e.m. ^*Significantly different from control; significantly different from control and PPG; all samples were from pooled bladders and analyzed in triplicate.