Heparin and hyperbaric oxygenation in enteric autonomic neuron preservation for transplant.

ABSTRACT

BACKGROUND: Previous studies have suggested that the addition of heparin to a preservation solution attenuated the autonomic dysfunction observed in rat jejunum and in addition that hypothermic hyperbaric oxygenation may play a role as a preservation technique. However, these studies did not address the lesion indices of the autonomic enteric neurons. We sought to investigate whether the autonomic enteric neurons are injured during cold ischemic preservation and whether administration of heparin or hyperbaric oxygenation prevents this lesion. METHODS: Jejunal segments (2 cm; n = 20) of Wistar rats (12-16 weeks old) were maintained in lactated Ringer's solution without or with heparin (H- and H+, respectively) at 4 degrees C under normobaric conditions. Other jejunal segments (n = 10) were maintained at 4 degrees C in H- under hyperbaric oxygenation conditions (HBO). After preservation for 12 hours, H-, H+, and HBO preparations fixed in 10% formaldehyde were stained with hematoxylin and eosin. The lesion indices were expressed as the mean number of affected neurons (karyorhexis, nuclear dislocation, cytoplasmic vacuolisation) per 100 neurons present in intramural ganglia. Statistical analysis was performed using the Mann-Whitney test (P < .05). RESULTS: The histologic studies showed that enteric autonomic neurons were damaged in H- jejunal segments. The lesion indices observed were karyorhexis 90/100, nuclear dislocation 85/100, and cytoplasmic vacuolization 82/100. The autonomic neurons in H+ and HBO segments seemed to be normal and significantly well-preserved (P < .001). CONCLUSION: Hypothermic hyperbaric oxygenation and heparin prevented lesions in cold ischemic preservation of enteric autonomic neurons.