Brassard J A, Meyers K M
Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California.
J Lab Clin Med. 1994 Jul;124(1):55-62.
The effects of azotemia on von Willebrand factor (vWf) plasma concentration, structure, and function were studied by utilizing canine models for both uremic bleeding and type I vWf deficiency (vWd). Seventy-five percent to 80% renal mass reduction in eight mixed-breed dogs induced marked azotemia (blood urea nitrogen [BUN] 103 +/- 7 mg/dl [mean +/- SEM]; creatinine 5.8 +/- 1 mg/dl) and prolonged mean buccal mucosal bleeding time (BMBT) from 1.8 +/- 0.2 minutes to 7.0 +/- 0.4 minutes. The mean vWf plasma concentration increased from 0.88 +/- 0.11 U/ml to 1.26 +/- 0.14 U/ml. The pre- and postsurgical sodium dodecyl sulfate-agarose gel electrophoresis multimeric patterns were similar in all dogs. Administration of cryoprecipitate from pooled azotemic mixed-breed dog plasma to five Doberman pinschers with type I vWd increased the mean plasma vWf from 0.14 +/- 0.01 U/ml to 0.48 +/- 0.04 U/ml and decreased the BMBT from 7.1 +/- 0.6 minutes to 3.14 +/- 0.09 minutes. After renal mass reduction, five type I vWd Dobermans developed marked azotemia (BUN 79 +/- 8.6 mg/dl; creatinine 3.7 +/- 0.6 mg/dl) and prolonged BMBT (16.1 +/- 3.6 minutes). Findings in the eight azotemic mixed-breed dogs indicated that (1) vWf plasma levels were normal to increased in azotemic dogs; (2) vWf structure and multimeric distribution were not altered in canine azotemia; and (3) vWf was functional when placed in a non-azotemic environment. The prolongation of the BMBT in azotemic vWd dogs indicated that factors other than alteration of vWf function were responsible for the prolonged BMBT in canine azotemia.
利用犬类尿毒症出血模型和I型血管性血友病因子缺乏症（vWd）模型，研究了氮质血症对血管性血友病因子（vWf）血浆浓度、结构和功能的影响。八只杂种犬肾质量减少75%至80%，导致明显的氮质血症（血尿素氮[BUN]103±7mg/dl[平均值±标准误]；肌酐5.8±1mg/dl），平均口腔黏膜出血时间（BMBT）从1.8±0.2分钟延长至7.0±0.4分钟。vWf血浆平均浓度从0.88±0.11U/ml增加至1.26±0.14U/ml。所有犬术前和术后十二烷基硫酸钠-琼脂糖凝胶电泳多聚体模式相似。将混合的氮质血症杂种犬血浆冷沉淀给予五只患有I型vWd的杜宾犬，使血浆vWf平均水平从0.14±0.01U/ml增加至0.48±0.04U/ml，并使BMBT从7.1±0.6分钟缩短至3.14±0.09分钟。肾质量减少后，五只I型vWd杜宾犬出现明显的氮质血症（BUN 79±8.6mg/dl；肌酐3.7±0.6mg/dl），BMBT延长（16.1±3.6分钟）。八只氮质血症杂种犬的研究结果表明：（1）氮质血症犬的vWf血浆水平正常或升高；（2）犬类氮质血症中vWf结构和多聚体分布未改变；（3）vWf置于非氮质血症环境中时具有功能。氮质血症vWd犬的BMBT延长表明，除vWf功能改变外，其他因素也导致了犬类氮质血症中BMBT延长。
