Abstract: Abstract: Objective To observe the effects of palygorskite corncob bedding on the contents of cytochrome P450 ( CytP450) and cytochrome b5 ( Cytb5) ，and activity of CYP1A2 and CYP2E1 in the rat liver cells． Method 120 SD rats were randomly divided into ordinary wood shavings group，corn stalk group，palygorskite corncob group and control group． The contents of CytP450 and Cytb5，and activity of CYP1A2 and CYP2E1 were determined after 30 days，60 days，and 90 days of feeding． Result After 60 days and 90 days of feeding，the difference in CytP450 content between ordinary wood shavings group and control group and between corn stalk group and control group was significant ( P ＜ 0. 05) ，however，the difference was not significant between palygorskite corncob group and the control group ( P ＞ 0. 05) ． The differences in liver microsomal Cytb5 content，and CYP1A2 and CYP2E1 activity were not significant among the groups ( P ＞ 0. 05) ． Conclusion The palygorsklte corncob did not exert inhibiting effect and inducing effect on liver microsomal CytP450，Cytb5，CYP1A2 and CYP2E1，and ordinary wood shavings had stronger inducing effect on rat liver CytP450 and corn stalk had weak inducing effect on rat liver CytP450．

Key words: the palygorskite corncob, bedding, cytochrome P450, inducing effect

摘要： 摘要: 目的观察凹土玉米芯垫料对大鼠肝脏细胞色素P450( CytP450) 、细胞色素b5( Cytb5) 含量及大鼠肝微粒 体CYP1A2 和CYP2E1 活性的影响。方法将SD 大鼠随机分为普通刨花组、玉米秸组、凹土玉米芯组和对照组，饲 养30 d、60 d、90 d 时测定大鼠肝脏微粒体CytP450、Cytb5 的含量和CYP1A2，CYP2E1 活性。结果60—90 d 时普 通刨花组、玉米秸组与空白对照组之间CytP450 含量有显著性差异( P ＜ 0. 05) ，凹土玉米芯组与对照组之间没有显 著性差异( P ＞ 0. 05) ; 肝微粒体Cytb5 含量、CYP1A2、CYP2E1 活性各组均没有明显差异( P ＞ 0. 05) 。结论凹土玉 米芯对大鼠肝脏细胞微粒体CytP450、Cytb5、CYP1A2 和CYP2E1 没有诱导或抑制作用，普通刨花组对大鼠肝 CytP450 有较强的诱导作用，玉米秸也有不同程度的诱导作用，但低于普通刨花的诱导作用。

关键词: 凹土玉米芯, 垫料, 细胞色素P450, 诱导作用