L-lysine α-oxidase (LO) is an L-amino acid oxidase with antitumor, antimicrobial and antiviral properties. Pharmacokinetic (PK) studies were carried out by measuring LO concentration in plasma and tissue samples by enzyme immunoassay. L-lysine concentration in samples was measured spectrophotometrically using LO. After single i.v. injection of 1.0, 1.5, 3.0 mg/kg the circulating T_1/2 of enzyme in mice varied from 51 to 74 min and the AUC_0–inf values were 6.54 ± 0.46, 8.66 ± 0.59, 9.47 ± 1.45 μg/ml × h, respectively. LO was distributed in tissues and determined within 48 h after administration with maximal accumulation in liver and heart tissues. Mean time to reach the maximum concentration was highest for the liver—9 h, kidney—1 h and 15 min for the tissues of heart, spleen and brain. T_1/2 of LO in tissues ranged from 7.75 ± 0.73 to 26.10 ± 2.60 h. In mice, plasma L-lysine decreased by 79% 15 min after LO administration in dose 1.6 mg/kg. The serum L-lysine levels remained very low from 1 to 9 h (< 25 μM, 17%), indicating an acute lack of L-lysine in animals for at least 9 h. Concentration of L-lysine in serum restored only 24 h after LO administration. The results of LO PK study show that it might be considered as a promising enzyme for further investigation as a potential anticancer agent.

L-赖氨酸 α-氧化酶 (LO) 是一种 L-氨基酸氧化酶，具有抗肿瘤、抗菌和抗病毒特性。药代动力学 (PK) 研究是通过酶免疫测定法测量血浆和组织样品中的 LO 浓度来进行的。使用 LO 分光光度法测量样品中的 L-赖氨酸浓度。单次静脉注射 1.0、1.5、3.0 mg/kg后，小鼠体内酶的循环 T _1/2从 51 到 74 分钟_不等，AUC _0–inf值分别为 6.54 ± 0.46、8.66 ± 0.59、9.47 ± 1.45 μg/ml × h。LO 分布在组织中，并在给药后 48 小时内测定，在肝脏和心脏组织中积累最大。肝脏达到最大浓度的平均时间最长为 9 小时，肾脏为 1 小时，心脏、脾脏和脑组织为 15 分钟。Ť _1/2组织中 LO 的范围从 7.75 ± 0.73 到 26.10 ± 2.60 小时。在小鼠中，以 1.6 mg/kg 剂量给予 LO 后 15 分钟，血浆 L-赖氨酸降低了 79%。从 1 小时到 9 小时，血清 L-赖氨酸水平仍然非常低（< 25 μM，17%），表明动物中 L-赖氨酸严重缺乏至少 9 小时。LO 给药后仅 24 小时，血清中 L-赖氨酸的浓度就恢复了。LO PK 研究的结果表明，它可能被认为是一种有前景的酶，可作为潜在的抗癌剂进行进一步研究。