牛妊娠早期、中期和晚期的肝脏类固醇代谢酶活性。
Hepatic steroid metabolizing enzyme activity during early, mid, and late bovine pregnancy.
作者信息
Hart C G, Camacho L E, Swanson K C, Vonnahme K A, Lemley C O
机构信息
Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
Department of Animal Sciences, North Dakota State University, Fargo, ND 58108, USA.
出版信息
Domest Anim Endocrinol. 2014 Oct;49:31-8. doi: 10.1016/j.domaniend.2014.05.003. Epub 2014 May 29.
The objective was to examine hepatic steroid inactivating enzymes throughout gestation and determine the effect of early to mid-gestation maternal nutrient restriction followed by realimentation on the activity of these enzymes. On day 30 of gestation, cows were assigned to dietary treatments: control (CON; 100% National Research Council; n = 18) and restricted (RES; 60% National Research Council; n = 30). On day 85, cows were slaughtered (CON, n = 6 and RES, n = 6), remained on control (CC, n = 12) and restricted (RR, n = 12), or were realimented to control (RC, n = 11). On day 140, cows were slaughtered (CC, n = 6; RR, n = 6; RC, n = 5), remained on control (CCC, n = 6; RCC, n = 5), or were realimented to control (RRC, n = 6). On day 254, all remaining cows were slaughtered. Jugular blood samples were collected before the slaughter for steroid analysis. At slaughter, maternal liver samples were collected for hepatic enzyme activity analysis. Activity of cytochrome P450 3A decreased (P = 0.05) from mid- to late-gestation. Peroxisome proliferator-activated receptor alpha DNA binding activity was increased (P < 0.01) on day 140 and 254 of gestation vs day 85. Concentrations of estradiol-17β (E2) increased (P < 0.01) as gestation proceeded, whereas progesterone concentrations (P4) tended to increase (P = 0.06) from mid- to late-gestation. Activity of cytochrome P450 1A and 2C were decreased (P < 0.05) in nutrient restricted cows vs control, whereas concentrations of E2 were increased (P < 0.05) in nutrient restricted cows vs control. A longer period of nutrient realimentation from mid- to late-gestation increased (P < 0.05) aldo-keto reductase 1C activity and decreased (P < 0.05) P4 concentrations compared with the shorter period of nutrient realimentation. In addition, significant negative correlations were observed for cytochrome P450 3A activity vs E2 (r(2) = -0.30; P < 0.05) and aldo-keto reductase 1C activity vs P4 (r(2) = -0.29; P < 0.05). The present study implicates hepatic steroid inactivation in the partial modulation of peripheral concentrations of E2 and P4 during gestation.
目的是研究整个妊娠期肝脏类固醇失活酶，并确定妊娠早期至中期母体营养限制后再喂食对这些酶活性的影响。在妊娠第30天，将奶牛分配到不同饮食处理组：对照组（CON；100%美国国家研究委员会标准；n = 18）和限制组（RES；60%美国国家研究委员会标准；n = 30）。在第85天，屠宰部分奶牛（CON组n = 6头，RES组n = 6头），其余奶牛继续维持对照饮食（CC组，n = 12头）和限制饮食（RR组，n = 12头），或改为对照饮食（RC组，n = 11头）。在第140天，屠宰部分奶牛（CC组n = 6头；RR组n = 6头；RC组n = 5头），其余奶牛继续维持对照饮食（CCC组，n = 6头；RCC组，n = 5头），或改为对照饮食（RRC组，n = 6头）。在第254天，屠宰所有剩余奶牛。屠宰前采集颈静脉血样进行类固醇分析。屠宰时，采集母体肝脏样本进行肝酶活性分析。细胞色素P450 3A的活性从妊娠中期到晚期降低（P = 0.05）。与妊娠第85天相比，妊娠第140天和第254天过氧化物酶体增殖物激活受体α DNA结合活性增加（P < 0.01）。随着妊娠进展，雌二醇-17β（E2）浓度升高（P < 0.01），而孕酮浓度（P4）从妊娠中期到晚期呈上升趋势（P = 0.06）。与对照组相比，营养限制奶牛的细胞色素P450 1A和2C活性降低（P < 0.05），而营养限制奶牛的E2浓度升高（P < 0.05）。与较短时间的营养再喂食相比，妊娠中期到晚期较长时间的营养再喂食增加了醛糖酮还原酶1C的活性（P < 0.05），并降低了P4浓度（P < 0.05）。此外，观察到细胞色素P450 3A活性与E2之间存在显著负相关（r(2) = -0.30；P < 0.05），醛糖酮还原酶1C活性与P4之间存在显著负相关（r(2) = -0.29；P < 0.05）。本研究表明，肝脏类固醇失活在妊娠期外周E2和P4浓度的部分调节中起作用。
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