摘要
BACKGROUND Alcoholism is regarded as a risk factor for vitamin B_(12)(VB_(12))deficiency.Because V B_(12) serves as a coenzyme of methylmalonyl-CoA mutase,a key enzyme in propionate metabolism,the ^(13)C-propionate breath test(PBT)has been studied as a non-invasive diagnostic modality for VB_(12) deficiency.However,the conventional PBT requires 2 h,which is inconvenient in clinical practice.We hypothesized that a faster PBT can be used to evaluate propionate metabolism and is more easily adaptable for clinical practice.AIM To evaluate a faster PBT for assessing the effects of long-term ethanol consumption on propionate metabolism in ethanol-fed rats(ERs).METHODS ERs were obtained by replacing standard drinking water(for control rats,CRs)with 16%ethanol solution in descendants of F344/DuCrj rats.Faster PBT was performed by administering ^(13)C-propionate aqueous solution to male and female ERs and CRs by inserting a metal tubule from the mouth to the stomach;exhaled gas was collected in a bag to measure its ^(13)CO_(2)/12CO_(2) isotope ratio via infrared isotope spectrometry.Serum VB_(12) and alanine transaminase(ALT)levels were measured via chemiluminescence immunoassay and the lactate dehydrogenaseultraviolet method,respectively.We evaluated statistical differences in mean body weight,change in ^(13)CO_(2)(Δ^(13)CO_(2)‰),peakΔ^(13)CO_(2)‰,and serum VB_(12) and ALT,between males and females and between ERs and CRs using the t-test and Mann-Whitney U test for normally and non-normally distributed variables,respectively.RESULTS Males weighed significantly more than females(P<0.001);CRs weighed significantly more than ERs(P<0.008).Δ^(13)CO_(2) reached a peak(C_(max))at 20 min and 30 min in females and males,respectively,decreasing after 20-30 min without rebound in all groups.Males had significantly higher C_(max) andΔ^(13)CO_(2) at 15-45 min than females(P<0.05;for all pairs).Propionate metabolism was enhanced in male ERs relative to male CRs,whereas metabolism did not differ markedly between ERs and CRs fo
基金
the Japan Society for the Promotion of Science KAKENHI Grant, No. JP21K18089
