Magnetic Resonance Spectroscopy for Evaluation of Liposome-Encapsulated Hemoglobin as a Resuscitation Fluid

Abstract:

Liposome-encapsulated hemoglobin (LEH) based on a novel, synthetic, non-phospholipid was developed, and evaluated for cerebral energy metabolism in a 40% hemorrhage rat model. The markers of tissue energetics were monitored by ¹H- and ³¹P-magnetic resonance spectroscopy (MRS). After hemorrhage, ¹H-MRS showed an increase in the levels of lactate and pyruvate. These markers returned to baseline values following LEH resuscitation. Both LEH and saline were able to exert a neuron-protective effect as indicated by the recovery of N-acetylaspartate. ³¹P MRS showed a fall in phosphocreatine after hemorrhage, which upon LEH or saline resuscitation returned to the baseline values. Similarly, inorganic phosphate increased after bleeding, but returned to normal after resuscitation. LEH resuscitation also recovered β-ATP levels, but saline resuscitation provided only a modest recovery. The results indicate the utility of MRS to monitor cerebral metabolism in hemorrhage/resuscitation. The data is also supportive of the new LEH formulation as an oxygen carrier.

Keywords::

• Liposome-encapsulated hemoglobin
• hypovolemic shock
• cerebral energy metabolism
• magnetic resonance spectroscopy

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.