DRUG ACETYLATION--BIOCHEMICAL AND MOLECULAR STUDIES

基因决定的药物新陈代谢差异会影响 特殊药物中毒的风险。这些代谢产物的鉴定 差异可以提供对这些疾病的发病机制的理解。 毒性反应，并可能有助于预防。一口井- 人类特有的药物遗传缺陷涉及缺乏 胞浆芳香胺N-乙酰转移酶(NAT)。NAT缺乏症一直是 与人类相关的药物毒性风险增加，如 磺胺类、普鲁卡因胺、肼和异烟肼。这只狗是 唯一自然发生的磺胺过敏症模型 人类。此外，这只狗在NAT中也有一个模糊的缺陷 活动。因此，这些研究的具体目的是 描述狗胞浆芳香胺N-乙酰化的这种缺陷， 比较其生化性质、分子基础和患病率 这一缺陷与在人类中描述的缺陷不同，并表征了 另一条微体乙酰化途径。最初，南方人 犬基因组DNA印迹和聚合酶链式反应扩增将用于 筛选犬NAT基因，然后对犬进行蛋白质印迹分析 肝细胞胞浆NAT蛋白。Northern印迹、DNA测序和 如果鉴定出犬NAT基因(S)，将进行基因表达研究。 如果没有发现犬类基因，与狗有关的食肉动物也会被发现 筛选NAT基因的存在以确定进化 基因丢失的本质。犬微粒体体外酶活性测定方法的研究 高效液相色谱检测将用于表征替代乙酰化 小路。

Genetically determined differences in drug metabolism can influence the risk of idiosyncratic drug toxicity. Identification of these metabolic differences can provide an understanding of the pathogenesis of these toxic reactions and may contribute to their prevention. One well- characterized pharmacogenetic defect in humans involves a deficiency of cytosolic arylamine N-acetyltransferase (NAT). NAT deficiency has been associated in humans with increased risk of toxicity from drugs such as sulfonamides, procainamide, hydralazine, and isoniazid. The dog is the only naturally occurring model for sulfonamide hypersensitivity in humans. In addition, the dog has a poorly defined defect in NAT activity. Therefore, the specific aims of these studies are to characterize this defect in cytosolic arylamine N-acetylation in dogs, to compare the biochemical nature, molecular basis, and prevalence of this defect to that described in humans, and to characterize the role of an alternative microsomal acetylation pathway. Initially, Southern blotting and PCR amplification of canine genomic DNA will be use to screen for canineNAT genes, followed by Western blot analysis of canine hepatic cytosol for NAT protein. Northern blotting, DNA sequencing, and gene expression will be pursued if canine NAT gene(s) are identified. If no canine genes are found, carnivores related to dogs will also be screened for the presence of NAT genes to determine the evolutionary nature of gene loss. In vitro enzymatic assays in canine microsomes and HPLC detection will be used to characterize alternative acetylation pathways.