Cairns J A, Klassen G A
Circulation. 1977 Aug;56(2):284-8. doi: 10.1161/01.cir.56.2.284.
Canine myocardial CPK was partially purified and injected into 11 conscious mongreal dogs. From serial serum CPK measurements in each dog, mean Kd was calculated as 0.0047 +/- 0.0009 (+/- SD) min-1. Correlation coefficients indicated that CPK disappearance rate was well described by a single exponential expression. Kd measured on consecutive days in four dogs varied minimally. CPK distribution space ranged from 74 to 134% of plasma volume. Propranolol loading with 0.3 mg/kg or 2 mg/kg, followed by hourly maintenance doses, resulted in increased Kd in eight of ten dogs, mean Kd rising from .0048 min-1 to .0059 min-1 (P less than 0.02). Propranolol appeared to increase plasma volume but had no significant effect on the relationship of CPK distribution space to plasma volume. If the serial CPK technique were used to measure infarct size, using an average Kd, propranolol might produce artifactual reduction of infarct size measuremnt by increasing Kd and possibly by increasing plasma volume. The obligation to assess the effect upon CPK Kd and distribution space of an agent designed to limit infarct size is apparent.
犬心肌肌酸磷酸激酶（CPK）被部分纯化后注射到11只清醒的杂种犬体内。通过对每只犬的血清CPK进行连续测量，计算出平均解离常数（Kd）为0.0047±0.0009（±标准差）分钟⁻¹。相关系数表明，CPK的消失速率可用单一指数表达式很好地描述。在四只犬中连续几天测量的Kd变化极小。CPK分布空间为血浆容积的74%至134%。以0.3毫克/千克或2毫克/千克的剂量静脉注射普萘洛尔，随后每小时给予维持剂量，结果在十只犬中有八只犬的Kd增加，平均Kd从0.0048分钟⁻¹升至0.0059分钟⁻¹（P<0.02）。普萘洛尔似乎增加了血浆容积，但对CPK分布空间与血浆容积的关系没有显著影响。如果使用连续CPK技术测量梗死面积，采用平均Kd值，普萘洛尔可能会通过增加Kd以及可能增加血浆容积而导致梗死面积测量值出现人为降低。显然，有必要评估旨在限制梗死面积的药物对CPK Kd和分布空间的影响。
