牛奶中雌性激素对雄性幼鼠血脂代谢的影响

Effects of Female Sex Hormones in Cow's Milk on Blood Lipid in Young Male Rats

目的研究牛奶中雌性激素对雄性幼鼠血脂代谢的影响。方法48只21日龄雄性SD幼鼠随机等分为4组,每组12只。分别定量喂食妊娠奶牛奶、市售纯牛奶、产后奶牛奶和实验配方奶。于其53日龄时应用全自动生化分析仪检测各组幼鼠血清总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)和尿肌酐(Cr)水平;应用免疫化学发光法(ICMA)检测各组幼鼠血清孕酮(P4)、尿游离雌三醇(UFE3)水平。采用SPSS13.0软件进行统计学分析。结果妊娠奶牛奶、市售纯牛奶、产后奶牛奶和实验配方奶乳清中的总雌二醇分别为1189.66pmol/L、833.98pmol/L、588.17pmol/L和286.48pmol/L;P4分别为9.76nmol/L、10.18nmol/L、2.83nmol/L和0.92nmol/L;血清TC分别为(1.78±0.29)mmol/L、(1.94±0.20)mmol/L、(2.10±0.28)mmol/L和(2.11±0.22)mmol/L,产后奶牛奶组和实验配方奶组与妊娠奶牛奶组比较差异均有统计学意义(Pa<0.05);4组间血清TG、HDL-C、LDL-C、P4和UFE3/Cr差异均无统计学意义(Pa>0.05)。结论妊娠奶牛奶可能对雄性SD幼鼠有降血清TC作用,其机制可能与雌二醇和P4联合作用有关。

Objective To investigate the effects of female sex hormones in cow＇s milk on metabolism of blood lipid in ＂young male rats. Methods Forty - eight male Sprague - Dawley rats aged 21 days old were assigned randomly to 4 groups, each containing 12 rats, and fed with quantitative milk from postpartum cow, milk from pregnant cow, commercial whole milk and artificial milk, respectively. Serum total cholesterol （ TC ）, triacylglyeriol （TG）, high - density lipoprotein cholesterol （ HDL - C ）, low - density lipoprotein cholesterol （ LDL - C ） and urinary creatinine （Cr） were determined with automatic biochemical analyzer. Serum progesterone（ P4 ） and urinary free estriol（ UFE3 ） were determined with immunochemiluminometric assays after all rats were killed at 53 days old. SPSS 13.0 software was used to analyze the data. Resuits Total estradiol and P4 were 1 189.66 pmol/L,833.98 pmol/L,588.17 pmol/L,286, 48 pmol/L and 9.76 nmol/L, 10.18 nmol/L, 2. 83 nmol/L,0.92 nmol/L in milk from pregnant cow,commercial whole milk,milk from postpartum cow and artificial milk groups,respectively. Serum TC were respectively （ 1.78± 0.29 ） mmol/L, （ 1.94 ± 0.20） mmol/L, （2.10 ± 0.28 ） mmol/L and （2.11 ±0.22 ） mmol/L in pregnant.milk, commercial whole milk, postpartum milk and artificial milk groups, and TC in pregnant milk group was lower than that in postpartum milk group or artificial milk group（ P 〈 0.05 ）. No difference was observed in serum TG, HDL - C, LDL - C, P4 and UFE3/Cr among 4 groups （P, 〉 0. 05）. Conclusion Milk from pregnant cow may reduce serum TC in young male SD rats, which may be related to the conjoined effect of estradiol and P4-