Liver regeneration and energetic changes in rats following hepatic radiation therapy and hepatocyte transplantation by ³¹P MRSI

Liver Int. 2015 Apr;35(4):1145-51. doi: 10.1111/liv.12507. Epub 2014 Mar 15.

Abstract

Background & aims: Radiation-induced liver damage (RILD) is a poorly understood and potentially devastating complication of hepatic radiation therapy (RT) for liver cancers. Previous work has demonstrated that hepatocyte transplantation (HT) can ameliorate RILD in rats. We hypothesized that RT inhibits generation of cellular ATP and suppresses hepatic regeneration.

Methods: To study the metabolic changes that occur in RILD with and without HT, (31)P MRSI data were acquired in rats treated with partial hepatectomy (PH) alone, PH with hepatic irradiation (PHRT) or PHRT with HT (PHRT+HT).

Results: Both [γ -ATP] and ATP/Pi (31)P MRSI signal ratio initially decreased and subsequently returned to baseline levels within 2 weeks after PH, which is consistent with other published data. Persistently reduced [γ-ATP] and ATP/Pi (31)P MRSI signal ratio were observed in rats up to 20 weeks after PHRT. However, progressive increases in [γ -ATP] were observed over time in the group of rats receiving PHRT+HT. Normal [γ -ATP] was observed 20 weeks after PHRT+HT (vs. PH alone), although, ATP/Pi levels did not return to normal after PHRT +HT. Ex vivo histological studies were performed to confirm liver repopulation with transplanted hepatocytes and the amelioration of pathologic changes of RILD.

Conclusions: These findings suggest that (31)P MRSI can be used to monitor the progress of RILD and its amelioration using transplanted hepatocytes to simultaneously restore metabolic function while replacing host hepatocytes damaged by RT.

Keywords: MR spectroscopy; hepatocyte; radiation‐induced liver damage; transplantation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Cell Proliferation
  • Energy Metabolism*
  • Hepatectomy / methods
  • Hepatocytes / metabolism
  • Hepatocytes / pathology
  • Hepatocytes / transplantation*
  • Liver / metabolism
  • Liver / pathology
  • Liver / physiopathology
  • Liver / surgery*
  • Liver Regeneration*
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Proton Magnetic Resonance Spectroscopy
  • Radiation Injuries, Experimental / metabolism
  • Radiation Injuries, Experimental / pathology
  • Radiation Injuries, Experimental / physiopathology
  • Radiation Injuries, Experimental / surgery*
  • Rats, Inbred F344
  • Recovery of Function
  • Time Factors

Substances

  • Adenosine Triphosphate