Hindman H B, Knox W E
Enzyme. 1978;23(6):395-403. doi: 10.1159/000458608.
A sensitive and precise assay of guanase was based on the conversion of 14C-guanine to uric acid in the presence of excess xanthine oxidase. The enzyme was entirely soluble in rat tissues and no inhibitors of it were detected. The most active tissues were red blood cells, lung and lactating mammary gland, with more than twice the activity of liver. The contained blood could account for the low activity in adult skeletal muscle and some other tissues. All fetal tissues examined were without activity. Activity in mammary gland rose fourfold during lactation and dropped precipitously during involution, with a secondary rise associated in time with the loss of cells from the gland. Reticulocytes present normally and after hemorrhagic anemia appeared to account for substantially all of the high guanase activity in red blood cells. The guanase level could be used to predict the degree of reticulocytosis in rats within confidence limits of +/- 0.2%. The virtual absence of guanase in human red cells was confirmed, even in bloods containing elevated reticulocyte numbers.
鸟嘌呤酶的一种灵敏且精确的测定方法是基于在过量黄嘌呤氧化酶存在的情况下，将14C - 鸟嘌呤转化为尿酸。该酶在大鼠组织中完全可溶，且未检测到其抑制剂。活性最高的组织是红细胞、肺和泌乳期乳腺，其活性是肝脏的两倍多。所含血液可解释成年骨骼肌和其他一些组织中活性较低的原因。所有检测的胎儿组织均无活性。乳腺中的活性在泌乳期间增加四倍，在退化期间急剧下降，伴随着与腺体细胞丢失时间相关的二次升高。正常情况下以及出血性贫血后出现的网织红细胞似乎是红细胞中所有高鸟嘌呤酶活性的主要来源。鸟嘌呤酶水平可用于在±0.2%的置信限内预测大鼠的网织红细胞增多程度。即使在网织红细胞数量升高的血液中，也证实了人类红细胞中几乎不存在鸟嘌呤酶。
