TY - JOUR
T1 - H2s concentrations in the heart after acute h2s administration
T2 - Methodological and physiological considerations
AU - Sonobe, Takashi
AU - Haouzi, Philippe
N1 - Publisher Copyright:
© 2016 the American Physiological Society.
PY - 2016/12
Y1 - 2016/12
N2 - In this study, we have tried to characterize the limits of the approach typically used to determine H2S concentrations in the heart based on the amount of H2S evaporating from heart homogenates—spontaneously, after reaction with a strong reducing agent, or in a very acidic solution. Heart homogenates were prepared from male rats in control conditions or after H2S infusion induced a transient cardiogenic shock (CS) or cardiac asystole (CA). Using a method of determination of gaseous H2S with a detection limit of 0.2 nmol, we found that the process of homogenization could lead to a total disappearance of free H2S unless performed in alkaline conditions. Yet, after restoration of neutral pH, free H2S concentration from samples processed in alkaline and nonalkaline milieus were similar and averaged ~0.2-0.4 nmol/g in both control and CS homogenate hearts and up to 100 nmol/g in the CA group. No additional H2S was released from control, CS, or CA hearts by using the reducing agent tris (2-carboxyethyl) phosphine or a strong acidic solution (pH < 2) to “free” H2S from combined pools. Of note, the reducing agent DTT produced a significant sulfide artifact and was not used. These data suggest that 1) free H2S found in heart homogenates is not a reflection of H2S present in a “living” heart and 2) the pool of combined sulfides, released in a strong reducing or acidic milieu, does not increase in the heart in a measurable manner even after toxic exposure to sulfide.
AB - In this study, we have tried to characterize the limits of the approach typically used to determine H2S concentrations in the heart based on the amount of H2S evaporating from heart homogenates—spontaneously, after reaction with a strong reducing agent, or in a very acidic solution. Heart homogenates were prepared from male rats in control conditions or after H2S infusion induced a transient cardiogenic shock (CS) or cardiac asystole (CA). Using a method of determination of gaseous H2S with a detection limit of 0.2 nmol, we found that the process of homogenization could lead to a total disappearance of free H2S unless performed in alkaline conditions. Yet, after restoration of neutral pH, free H2S concentration from samples processed in alkaline and nonalkaline milieus were similar and averaged ~0.2-0.4 nmol/g in both control and CS homogenate hearts and up to 100 nmol/g in the CA group. No additional H2S was released from control, CS, or CA hearts by using the reducing agent tris (2-carboxyethyl) phosphine or a strong acidic solution (pH < 2) to “free” H2S from combined pools. Of note, the reducing agent DTT produced a significant sulfide artifact and was not used. These data suggest that 1) free H2S found in heart homogenates is not a reflection of H2S present in a “living” heart and 2) the pool of combined sulfides, released in a strong reducing or acidic milieu, does not increase in the heart in a measurable manner even after toxic exposure to sulfide.
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U2 - 10.1152/ajpheart.00464.2016
DO - 10.1152/ajpheart.00464.2016
M3 - Article
C2 - 27638880
AN - SCOPUS:85005950727
SN - 0363-6135
VL - 311
SP - H1445-H1458
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 6
ER -