Spurling N W, Savory J
Thromb Haemost. 1978 Jun 30;39(3):592-9.
One-stage prothrombin times of normal and of factor VII-deficient beagle plasma were determined with two types of beagle brain thromboplastin, one prepared from normal beagles and the other from factor VII-deficient beagles. There was little difference between the reagents in the prothrombin times obtained for normal plasma. However, when factor VII-deficient plasma was tested, reagent prepared from factor VII-deficient beagles gave considerably longer prothrombin times than were obtained with the normal reagent and the difference increased with increasing reagent concentration to a maximum at 140 mg/ml. Prothrombin times of a series of mixtures of normal and factor VII-deficient plasma indicated that the presence of only 1/90 part of normal plasma was necessary to compensate for the difference between the two reagents. Determination of the iron content of the reagent suggested that the microcirculation of an average brain contained some 1.8 g of whole blood. The finding that brain thromboplastin prepared from factor VII-deficient beagles is more sensitive to a deficiency of factor VII in plasma, presumably a result of the smaller quantity of factor VII present in the reagent, is compatible with the known kinetics of extrinsic coagulation.
用两种比格犬脑凝血活酶测定正常比格犬血浆和因子 VII 缺乏比格犬血浆的一期凝血酶原时间，一种由正常比格犬制备，另一种由因子 VII 缺乏比格犬制备。对于正常血浆，两种试剂所测得的凝血酶原时间几乎没有差异。然而，当检测因子 VII 缺乏血浆时，由因子 VII 缺乏比格犬制备的试剂所测得的凝血酶原时间比用正常试剂测得的长得多，且随着试剂浓度增加，差异增大，在 140 mg/ml 时达到最大。一系列正常血浆与因子 VII 缺乏血浆混合物的凝血酶原时间表明，仅 1/90 份正常血浆的存在就足以弥补两种试剂之间的差异。试剂铁含量的测定表明，平均大脑的微循环中约含有 1.8 g 全血。由因子 VII 缺乏比格犬制备的脑凝血活酶对血浆中因子 VII 缺乏更敏感，这一发现可能是由于试剂中因子 VII 含量较少，与已知的外源性凝血动力学相符。
