Different effects of partial pressure in a high-pressure gaseous mixture of carbon monoxide and oxygen for rat heart preservation

Naoyuki Hatayama,Hiroki Yokota,Kaori Fukushige,Shuichi Hirai,Masahiro Itoh,Munekazu Naito

doi:10.1038/s41598-019-43905-0

Naoyuki Hatayama, Hiroki Yokota + Show 4 more

Open Access

https://doi.org/10.1038/s41598-019-43905-0

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Abstract

We maintained the function of an extracted rat heart after 24–48 h preservation in a high-pressure gaseous mixture of carbon monoxide (CO) and oxygen (O2). Here, we assessed the effects of different partial pressures of hyperbaric CO and O2 for 24–48 h at 4 °C on rat heart preservation and compared conditions including immersion in University of Wisconsin solution. Preserved hearts were transplanted into recipient rats via heterotopic cervical heart transplantation for in vivo evaluation and perfused using the Langendorff system for ex vivo evaluation. The survival rate of transplanted hearts was 100% at postoperative day 7 in the CO + O2 (PCO:PO2 = 1.5:2.0 atm) group but only 33% in the CO + O2 (PCO:PO2 = 2.0:1.5 atm) group. Langendorff system and histopathological analysis revealed that the left ventricular pressure of preserved hearts in the CO + O2 (PCO:PO2 = 1.5:2.0 atm) group was better than the CO + O2 (PCO:PO2 = 2.0:1.5 atm). We demonstrate that exposure of rat hearts to hyperbaric CO and O2 is superior to the immersion method and that partial pressure of hyperbaric CO and O2 is crucial to preservation.

Highlights

Carbon monoxide (CO) is regarded as poisonous because of its high affinity for haemoglobin that causes rapid elevation of carboxyhemoglobin to toxic levels that compromise oxygen delivery to the tissues[1,2]
We developed a high-pressure gas (HPG) preservation method using a mixture of carbon monoxide (CO) and O2 gases and succeeded in resuscitating extracted rat hearts following 48 h of preservation under conditions of CO + O2 (PCO:PO2 = 4:3 atm)[13]
University of Wisconsin (UW) solution was vigorously bubbled at 4 °C before use for 5 min with compressed 5% CO gas mixed in air

Summary

Introduction

Carbon monoxide (CO) is regarded as poisonous because of its high affinity for haemoglobin that causes rapid elevation of carboxyhemoglobin to toxic levels that compromise oxygen delivery to the tissues[1,2]. We developed a high-pressure gas (HPG) preservation method using a mixture of CO and O2 gases and succeeded in resuscitating extracted rat hearts following 48 h of preservation under conditions of CO + O2 (PCO:PO2 = 4:3 atm)[13]. We selected a lower partial pressure mixed gas composed of CO + O2 (PCO:PO2 = 2.0:1.5 atm) for kidney graft and found an improved graft survival[16]. In this way, the appropriate total and partial pressures differ for each organ, and the partial pressures of CO and O2 for HPG remain unknown. This study aimed to evaluate the difference of partial pressure between CO and O2 on HPG in rat hearts

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