U. Kreutzer et T. Jue, METABOLIC RESPONSE IN ARENICOLA-MARINA TO LIMITING OXYGEN AS REFLECTED IN THE H-1-NMR OXYMYOGLOBIN SIGNAL, European journal of biochemistry, 243(1-2), 1997, pp. 233-239
Many intertidal animals can endure prolonged periods of environmental
stress and have developed strategies to preserve a functioning energy
state in the cell. Recent H-1/P-31-NMR techniques have allowed investi
gators to monitor directly mammalian tissue metabolism in vivo. In par
ticular, the signals of myoglobin (Mb) offer a unique opportunity to e
xplore the intracellular oxygen-partial-pressure [p(O-2)] interaction
in Arenicola marina, a standard model to study hypoxia tolerance in in
vertebrates. The present study reveals that the H-1-NMR MbO(2) signal
at -2.9 ppm is detectable in tissue and reflects directly the oxygenat
ed state. As the p(O-2) declines, MbO(2) saturation and oxygen consump
tion decrease. However, phosphotaurocyamine concentration remains unal
tered until the MbO(2) saturation falls below 33%. The extracellular t
o intracellular p(O-2) gradient appears substantial. The study establi
shes the H-1-NMR technique as an approach to measure the intracellular
p(O-2) with an oxygenated state marker and presents the interrelation
ship between oxygen and the metabolic adaptation during hypoxic stress
.