Measurement of pentane in expiratory gas during rabbit hepatic ischemia/reperfusion by solid-phase microextraction and gas chromatography–mass spectrometry (SPME GC/MS)

Abstract

The aim of this study was to determine the changes in the pentane concentration of expiratory gas as well as the relationship between this pentane concentration and hepatic oxidative stress during rabbit hepatic ischemia/reperfusion using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC/MS). 45 white male rabbits with body weights between 2.5 and 3.0 kg were randomly assigned to the following three groups: the 10 min ischemia group (group S); the 20 min ischemia group (group M); or the 30 min ischemia group (group L). Expiratory gases were collected prior to ischemia (T0) and for 1, 10, 20, 30, 60 and 120 min (T1-T6) following reperfusion. Pentane concentrations were determined using SPME and GC/MS. In addition, arterial blood samples were collected, and serum aminotransferase (AST) and malondialdehyde (MDA) concentrations were measured. In the three groups, the pentane concentrations of the expiratory gases at points T1 and T2 were significantly increased (P < 0.05) compared with those at point T0, and the serum AST and MDA concentrations at points T5 and T6 were also significantly increased (P < 0.05) compared with those at point T0. Therefore, the use of SPME in combination with GC/MS represents an improved anesthesia system that can be used to continuously measure the concentration of pentane in expiratory gases, which can reflect the degree of oxidative stress during hepatic ischemia/reperfusion.

A systematic review on the detection of volatile organic compounds in exhaled breath in experimental animals in the context of gastrointestinal and hepatic diseases

“…Overall, the sample size ranged from 5 to 56 animals. Only 6 of the studies used a separate control group [ 32 – 35 , 38 , 39 ] whereas the other studies used animals as their own control collecting breath samples prior to disease induction [ 36 , 37 , 40 , 41 ]. Standardization of diet, fasting status, day/night rhythm and environmental air varied between the included studies.…”

“…For 1 of these studies, the diet was specifically adapted to a high-fat diet in order to induce non-alcoholic steatohepatitis [ 32 ]. In the other 5 studies, all animal had ad libitum access to a standard chow and water [ 33 , 34 , 37 , 39 , 41 ]. A period of fasting, prior to breath collection, was applied in 4 of the 10 (40%) studies [ 34 , 37 , 39 , 40 ].…”

“…In the other 5 studies, all animal had ad libitum access to a standard chow and water [ 33 , 34 , 37 , 39 , 41 ]. A period of fasting, prior to breath collection, was applied in 4 of the 10 (40%) studies [ 34 , 37 , 39 , 40 ]. In all of these studies fasting consisted of 12 hours food restriction, but unlimited access to water.…”

“…Standardization of the day/night rhythm is described in 4 of the 10 studies using 12h/12h light/dark cycles [ 32 , 35 , 37 , 40 ]. In only 3 studies, measures were taken to limit possible influences of environmental air by either by collecting and analyzing the room air [ 33 ], collecting both room air and blanks of the sampling system [ 35 ] or using highly purified synthetic air for ventilation of the experimental animal [ 34 ].…”

“…70% of the studies (n = 7) reported the use of anesthetics while collecting exhaled air via a tracheal cannula or tracheostomy [ 33 – 37 , 39 , 40 ]. Although the method of anesthesia differs, all studies describe the specific anesthetic agent that was used.…”