Edman P, Nylén U, Sjöholm I
J Pharmacol Exp Ther. 1983 Apr;225(1):164-7.
L-asparaginase was immobilized under aseptic conditions in spherical microparticles of polyacrylamide. To avoid direct contact between blood and enzyme, we have applied the immobilized L-asparaginase in microparticles on the outer surface of the capillary fibers of a hemofilter. The hemofilters were very efficient in the transformation of L-asparagine to L-aspartic acid, both in vitro and in vivo. L-Asparagine in buffer (50 microM in 5 liters) was converted to L-aspartic acid within 60 min after circulation through a hemofilter containing 2000 I.U. of L-asparaginase. Circulating L-asparagine in healthy sheep (about 40-50 microM was reduced to low levels after 2 to 3 hr of perfusion with a unit containing 2000 I.U. of L-asparaginase. The reduction persisted for 3 to 4 hr after terminated treatment. Repeated, extracorporeal treatments in sheep showed that the L-asparagine decrease induced an increased resynthesis of L-asparagine, probably due to the action of the L-asparagine synthetase.
L-天冬酰胺酶在无菌条件下固定于聚丙烯酰胺球形微粒中。为避免血液与酶直接接触，我们将固定化L-天冬酰胺酶应用于血液滤过器毛细管纤维外表面的微粒中。该血液滤过器在体外和体内将L-天冬酰胺转化为L-天冬氨酸方面都非常有效。缓冲液中的L-天冬酰胺（5升中50微摩尔）在通过含有2000国际单位L-天冬酰胺酶的血液滤过器循环60分钟内转化为L-天冬氨酸。健康绵羊体内循环的L-天冬酰胺（约40 - 50微摩尔）在用含有2000国际单位L-天冬酰胺酶的装置灌注2至3小时后降至低水平。终止治疗后，这种降低持续3至4小时。绵羊的重复体外治疗表明，L-天冬酰胺的减少导致L-天冬酰胺的再合成增加，这可能是由于L-天冬酰胺合成酶的作用。
