Tissue-dependent variation of hydrogen sulfide homeostasis in anoxic freshwater turtles

TY - JOUR

T1 - Tissue-dependent variation of hydrogen sulfide homeostasis in anoxic freshwater turtles

AU - Jensen, Birgitte

AU - Pardue, Sibile

AU - Kevil, Christopher G.

AU - Fago, Angela

PY - 2019/6

Y1 - 2019/6

N2 - Hydrogen sulfide (H2S) controls numerous physiological responses. To understand its proposed role in metabolic suppression, we measured free H2S and bound sulfane sulfur (BSS) in tissues of the freshwater turtle Trachemys scripta elegans, a species undergoing strong metabolic suppression when cold and anoxic. In warm normoxic turtles, free H2S was higher in red blood cells (RBCs) and kidney (∼9–10 µmol l−1) than in brain, liver and lung (∼1–2 µmol l−1). These values overall aligned with the tissue H2S-generating enzymatic activity. BSS levels were similar in all tissues (∼0.5 µmol l−1) but ∼100-fold higher in RBCs, which have a high thiol content, suggesting that RBCs function as a circulating H2S reservoir. Cold acclimation caused significant changes in free and bound H2S in liver, brain and RBCs, but anoxia had no further effect, except in the brain. These results show tissue-dependent sulfide signaling with a potential role in brain metabolic suppression during anoxia in turtles.

AB - Hydrogen sulfide (H2S) controls numerous physiological responses. To understand its proposed role in metabolic suppression, we measured free H2S and bound sulfane sulfur (BSS) in tissues of the freshwater turtle Trachemys scripta elegans, a species undergoing strong metabolic suppression when cold and anoxic. In warm normoxic turtles, free H2S was higher in red blood cells (RBCs) and kidney (∼9–10 µmol l−1) than in brain, liver and lung (∼1–2 µmol l−1). These values overall aligned with the tissue H2S-generating enzymatic activity. BSS levels were similar in all tissues (∼0.5 µmol l−1) but ∼100-fold higher in RBCs, which have a high thiol content, suggesting that RBCs function as a circulating H2S reservoir. Cold acclimation caused significant changes in free and bound H2S in liver, brain and RBCs, but anoxia had no further effect, except in the brain. These results show tissue-dependent sulfide signaling with a potential role in brain metabolic suppression during anoxia in turtles.

KW - Anoxia

KW - Gasotransmitter

KW - Metabolic suppression

KW - Red blood cell

KW - Trachemys scripta

UR - http://www.scopus.com/inward/record.url?scp=85068238631&partnerID=8YFLogxK

U2 - 10.1242/jeb.203976

DO - 10.1242/jeb.203976

M3 - Journal article

C2 - 31109970

AN - SCOPUS:85068238631

SN - 0022-0949

VL - 222

JO - Journal of Experimental Biology

JF - Journal of Experimental Biology

IS - 12

M1 - jeb203976

ER -