[ 摘要 ]

人類乙醯化作用為多形性，在單一正染色體的特定部位上，有兩個主要的對偶基因，共同調節肝臟乙醯轉移酵素（ N-acetyltransferase ）的活性， 其表現型可區分為快型與慢型兩種。本研究以咖啡因（ Caffeine）為一代謝探針，應用於台灣地區原住民不同族別間之乙醯氾基因表現型 分佈， 以六個原住民鄉的國中， 840 位學童為研究樣本，給予喝一罐市售罐裝咖啡， 2 小時後收集單次尿液以高效率液相層析法（ HPLC ），分析尿液中兩個咖啡因之主要代謝物， AFMU （ 5-acetylamino-6- formylamino-3-methyluracil ）與 1X （1-methylxanthine ）之Peak area ratio 來辨別乙醯化作用的狀態。研究結果顯示，乙醯化作用之遺傳表現型自然呈現 Trimodal 分佈，各族慢型乙醯化比例由高到低順序為排灣族I 48.95 ％、泰雅族 48.81 ％、阿美族 29.82 ％、排灣族II 29.17 ％、布農族23.08％、閩南人 21.26 ％， 客家人慢型比例最低， 只有 14.81 ％，原住民混合慢型佔 37.29％， 介於最高與最低之間，而其他混合慢型佔 19.67 ％，接近閩南人慢型乙醯化比例。族別間表現型的差異具有統計上顯著相關。 AFMU/1X ratio 在各種影響因素中， 以性別具統計顯著差異，抽菸、喝酒、是否生病與是否服藥均無差別。快型與慢型在各種相關因素之間則完全無統計之顯著差異，差異完全由族別所引起。根據族群遺傳學定律，本研究之乙醯化作用三基因型 rr（同型合子慢型）、 Rr （異型合子快型）、 RR （同型合子快型）的分佈， 除阿美族外，基因頻率均與哈溫平衡定律一致。

[ 英文摘要 ]

Acetylation activity is polymorphism. The liver N-acetyl-

transferase isgoverned by two major alleles at a single

autosomal locus, the phenotype canbe classified as ''''slow'''' and

''''fast''''. Caffeine used as a metabolic probe foracetylator

phenotyping in Taiwan aborigines. 840 students of 6 middle

schoolin aboriginal regions were studied. We collected 2 hour

spot urine sampleafter a can of coffee was drank. We

determined the acetylator phenotype statusby! measuring the

peak area ratio of two caffeine metabolites,

5-acetylamino-6-formylamino-3- methyl-uracil (AFMU) and

1-methylxanthine (1X),using a high- performance liquid

chromatographic method. The frequencydistribution of

acetylator phenotype had been demonstrated to be trimodal.

Theslow acetylator was 48.95% in PaiwanI, 48.81% in Atayal,

29.82% in Ami, 29.17%in PaiwanII, 23.08% in Bunun, 21.26% in

Fukien-Taiwanese, 14.81% in Hakka isthe lowest. Aboriginal

mixed is 37.29%, between the highest and the lowestfrequency

of aborigines. Other mixed is 19.67%, closed to Fukien-

Taiwanese.The interethnic difference was related to the status

of acetylator phenotype.Genders were relative to AFMU/1X ratio,

but smoke, drink, sick and drugs werenot. According to

trimodal distribution of acetylator phenotype,

thedistribution of genotype of rr (homozygous slow acetylator),

Rr (heterozygousacetylator), RR(homozygous rapid

acetylator) were consistent withHardy-Weinberg theory of

population genetics, except Ami.