Cighetti G, Del Puppo M, Paroni R, Galli Kienle M
University of Milan, Italy.
FEBS Lett. 1990 Nov 12;274(1-2):82-4. doi: 10.1016/0014-5793(90)81334-k.
Irreversible transformation of xanthine dehydrogenase (XDH) to xanthine oxidase (XO) during ischemia was determined measuring XDH and total enzyme activity in kidneys before and after 60 min of clamp of the renal pedicle. Tissue levels of adenine nucleotides, xanthine and hypoxanthine were used as indicators of ischemia. After 60 min of clamping, ATP levels decreased by 72% with respect to controls whereas xanthine and hypoxanthine progressively reached tissue concentrations of 732 +/- 49 and 979 +/- 15 nmol.g tissue-1, respectively. Both total and XDH activities in ischemic kidneys (30 +/- 15 and 19 +/- 1 nmol.min-1.g tissue-1) were significantly lower than in controls when expressed on a tissue weight basis. The fraction of enzyme in the XDH form was however unchanged indicating that the reduction of the nucleotide pool is not accompanied by induction of the type-O activity of xanthine oxidase.
通过测量肾蒂夹闭60分钟前后肾脏中黄嘌呤脱氢酶（XDH）和总酶活性，确定了缺血过程中黄嘌呤脱氢酶向黄嘌呤氧化酶（XO）的不可逆转变。腺嘌呤核苷酸、黄嘌呤和次黄嘌呤的组织水平被用作缺血指标。夹闭60分钟后，与对照组相比，ATP水平下降了72%，而黄嘌呤和次黄嘌呤的组织浓度分别逐渐达到732±49和979±15 nmol·g组织-1。以组织重量为基础表示时，缺血肾脏中的总活性和XDH活性（分别为30±15和19±1 nmol·min-1·g组织-1）均显著低于对照组。然而，XDH形式的酶比例没有变化，这表明核苷酸池的减少并未伴随着黄嘌呤氧化酶O型活性的诱导。
