THE EFFECTS OF HALOTHANE AND ISOFLURANE ON THE PHOSPHOENERGETIC STATEOF THE LIVER DURING HEMORRHAGIC-SHOCK IN RATS - AN IN-VIVO P-31 NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPIC STUDY

We studied the effects of halothane versus isoflurane on the phosphoen ergetic state and intracellular pH (pH(i)) of the rat liver using in v ivo P-31 nuclear magnetic resonance (NMR) spectroscopy during and afte r hemorrhagic shock. Seventeen rats were anesthetized with 1 minimum a lveolar anesthetic concentration of halothane or isoflurane. The mean arterial blood pressure was reduced to 40 mm Hg and maintained at this level for 45 min by withdrawing blood from the common carotid artery. The shed blood was then returned slowly. In vivo P-31 NMR spectra wer e consecutively collected throughout the study. The phosphoenergetic s tate of the liver was evaluated from the changes in adenosine triphosp hate (ATP) and inorganic phosphate (P-i) levels. pH(i) was calculated from the chemical shifts of P-i and alpha-ATP peaks. During hemorrhagi c shock, beta-ATP decreased to 35% and 45%, and P-i increased to 300% and 230% of their initial values in the halothane and isoflurane group s, respectively. Intracellular acidosis was more severe in the halotha ne group. The recoveries of beta-ATP and P-i were better in the isoflu rane group. Halothane showed a more detrimental effect than isoflurane on the hepatic phosphoenergetic level during and after hemorrhagic sh ock.