连续监测法测定血清山梨醇脱氢酶

Kinetic determination of serum sorbitol dehyrogenase activity

以ＮＡＤ＋、山梨醇为底物，３７℃ｐＨ１０的甘氨酸／氢氧化钠为缓冲体系，建立血清山梨醇脱氢酶（ＳＤＨ）的连续监测法。ＮＡＤ＋、山梨醇和Ｚｎ２＋的最终浓度分别为０．４７、１９和１．９ｍｍｏｌ／Ｌ，ＫＮＡＤ＋、Ｋ山梨醇分别为０．０９和１．２ｍｍｏｌ／Ｌ。在此条件下，确定ＳＤＨ线性范围为０～１８０Ｕ／Ｌ，批内ＣＶ为３．９％，批间ＣＶ为５．２％，６０例健康成人血清ＳＤＨ正常参考值为０～３．１Ｕ／Ｌ。初步临床观察表明，急性肝损伤时该酶明显升高，肝外梗阻、心肌梗塞等非肝病患者血清ＳＤＨ一般不增高。

Serum sorbitol dehydrogenase(SDH)activity was determined by kinetic assay,and the enzymic reaction was researched.The assay contained 0 47 mmol/L NAD +,19 mmol/L D sorbitol and 1 9 mmol/L Zn 2+ in 0 1 mol/L glycine buffer,pH 10 0(37℃).The Km for serum SDH were 1 2 mmol/L(D sorbitol)and 0 09 mmol/L(NAD +)respectively.This method had a detection limit of 180 U/L,within run CV 3 9% and day to day CV 5 2%.In a prospective study,we investigated 60 healthy volunteers,and obtained normal values for serum SDH fron 0 to 3 1 U/L.Via clinical observation,it showed that serum SDH activity increased significantly at hepatic diseases,and hardly changed at non hepatic disease cases such as obstructive jaundice,myocardial infraction,etc.