Gaskill Cynthia L, Hoffmann Walter E, Cribb Alastair E
Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada.
Vet Clin Pathol. 2004;33(4):215-22. doi: 10.1111/j.1939-165x.2004.tb00376.x.
Serum total alkaline phosphatase (AP) activity commonly is high in dogs receiving phenobarbital. Specific isoenzymes responsible for this increase are not well documented.
The purposes of this study were 1) to qualitatively and quantitatively describe serum AP isoenzymes in phenobarbital-treated dogs and 2) to monitor changes in serum AP isoenzyme activities associated with phenobarbital treatment over time.
Serum AP isoenzyme activities were determined in a cross-sectional study of 29 dogs receiving phenobarbital (duration of treatment 2 months to 6.5 years). Additionally, in a prospective study of 23 dogs, serum AP isoenzyme activities were determined before and 3 weeks, 6 months, and 12 months after the start of phenobarbital treatment. Isoenzyme activities were quantitatively determined using wheat germ lectin precipitation and levamisole inhibition, and qualitatively (ie, present or absent) evaluated using cellulose acetate affinity electrophoresis.
In phenobarbital-treated dogs with high serum total AP activity in the cross-sectional study, the increase was due predominantly to increased activities of the corticosteroid-induced (C-AP) and liver (L-AP) isoenzymes. Prospectively, serum total AP and L-AP activities were significantly higher at 3 weeks, 6 months, and 12 months after the start of phenobarbital treatment compared with pretreatment values. Serum C-AP and bone isoenzyme (B-AP) activities were significantly higher after 6 and 12 months of treatment. B-AP accounted for only a small amount of the total AP activity. No unusual or previously unidentified AP isoenzymes were identified.
Phenobarbital treatment was associated with increased C-AP and L-AP isoenzyme activities and with a minor increase in B-AP activity. No unique "phenobarbital-induced" isoenzyme was identified. Isoenzyme analysis does not appear to be useful for differentiating between high serum total AP due to phenobarbital therapy and other causes.
接受苯巴比妥治疗的犬血清总碱性磷酸酶（AP）活性通常较高。导致这种升高的特定同工酶尚无充分记录。
本研究的目的是：1）定性和定量描述接受苯巴比妥治疗的犬血清AP同工酶；2）监测与苯巴比妥治疗相关的血清AP同工酶活性随时间的变化。
在一项横断面研究中，对29只接受苯巴比妥治疗（治疗持续时间为2个月至6.5年）的犬测定血清AP同工酶活性。此外，在一项对23只犬的前瞻性研究中，在苯巴比妥治疗开始前以及开始后3周、6个月和12个月测定血清AP同工酶活性。使用麦胚凝集素沉淀法和左旋咪唑抑制法对同工酶活性进行定量测定，并使用醋酸纤维素亲和电泳进行定性（即存在或不存在）评估。
在横断面研究中，血清总AP活性高的苯巴比妥治疗犬中，升高主要归因于皮质类固醇诱导的（C-AP）和肝脏（L-AP）同工酶活性增加。前瞻性研究中，与治疗前值相比，苯巴比妥治疗开始后3周、6个月和12个月时血清总AP和L-AP活性显著更高。治疗6个月和12个月后，血清C-AP和骨同工酶（B-AP）活性显著更高。B-AP仅占总AP活性的一小部分。未鉴定出异常或先前未识别的AP同工酶。
苯巴比妥治疗与C-AP和L-AP同工酶活性增加以及B-AP活性轻微增加有关。未鉴定出独特的“苯巴比妥诱导的”同工酶。同工酶分析似乎无助于区分苯巴比妥治疗引起的血清总AP升高与其他原因。
