The roles of the insulin-like growth factor system and leptin as possible mediators of the effects of nutritional restriction on age at puberty and compensatory growth in dairy heifers.
The roles of the insulin-like growth factor system and leptin as possible mediators of the effects of nutritional restriction on age at puberty and compensatory growth in dairy heifers.
复制标题
胰岛素样生长因子系统和瘦素作为营养限制对青春期年龄和奶牛代偿性生长影响的可能介质的作用。
DOI：
10.4314/sajas.v30i2.3865
复制
发表时间：
2000
影响因子：
0.8
通讯作者：
P. Cronjé
中科院分区：
文献类型：
--
作者：
G. Luna;P. Cronjé
本实验的目的是确定胰岛素样生长因子-1（IGF-1）、IGF结合蛋白（IGFBPs）、瘦素和葡萄糖的血液浓度变化在多大程度上与黑白花小母牛青春期的补偿性生长和年龄相关。将12头小母牛（6个月大; 179.8 kg体重）分配至两种饮食处理之一，持续30周。处理被设计成在实验的前13周期间产生两种不同的生长速率，即0.3kg/d（限制处理）或0.6kg/d（对照处理）。从第14周至第30周，限制组接受与对照组相同量的饲料/kg体重（补偿期）。对照组的小母牛比限制组提前四周进入青春期。青春期平均体重为256.3 kg，未受给药影响。在补偿阶段，与对照组相比，先前限制的动物的生长速率更大，饲料转化率上级。血浆IGF-1和IGFBP-3浓度在限制组高于对照组在早期代偿期。IGFBP-3的浓度增加，并在青春期达到峰值，即使青春期发生在不同的年龄。相反，IGF-1的浓度在先前限制的动物中在最大生长速率点达到峰值，并且在两种治疗中与青春期年龄没有明确的关系。血浆瘦素浓度增加，直到青春期在两个治疗，即使青春期的日期不同。在青春期，两种治疗的血糖浓度均未发生变化;然而，在限制期后发现治疗之间存在差异。治疗或采样期间IGFBP-2浓度无差异。可以得出结论，葡萄糖，IGF-1和IGFBP-3的浓度受到营养限制和饱食，并可能在一定程度上有助于补偿性生长的内分泌调节。提示青春期发育过程中瘦素和IGFBP-3浓度的升高可能是青春期开始的生理信号。
（南非动物科学杂志，2000，30（2）：155-163）
The aim of this experiment was to determine to what extent changes in the blood concentrations of insulin-like growth factor-1 (IGF-1), IGF binding proteins (IGFBPs), leptin and glucose are associated with compensatory growth and age at puberty in Friesian heifers. Twelve heifers (6 months old; 179.8 kg body weight) were allocated to one of two dietary treatments for 30 weeks. Treatments were designed to result in two different growth rates during the first 13 weeks of the experiment, viz. 0.3 kg/d (restriction treatment) or 0.6 kg/d (control treatment). From week 14 to 30, the restricted group received the same amount of feed per kg bodyweight as was fed to the control group (compensatory phase). Heifers in the control treatment reached puberty four weeks earlier than the restricted group. Mean body weight at puberty was 256.3 kg and was not affected by treatment. During the compensatory phase, the growth rate of the previously restricted animals was greater, and feed conversion ratio superior, compared to that of the control group. Plasma IGF-1 and IGFBP-3 concentrations were higher in the restricted group than in the control group during the early compensatory phase. Concentrations of IGFBP-3 increased and peaked at puberty for both treatments, even though puberty occurred at different ages. In contrast, concentrations of IGF-1 peaked at the point of maximum growth rate in the previously restricted animals, and in neither treatment was there a clear relationship with the age of puberty. Plasma leptin concentrations increased until puberty in both treatments even though the date of puberty differed. Plasma glucose concentration did not change at puberty for either treatment; however, differences between treatments were found after the restriction period. There were no differences in IGFBP-2 concentrations between treatments or sampling periods. It is concluded that concentrations of glucose, IGF-1 and IGFBP-3 are affected by nutritional restriction and repletion, and may contribute in some measure to the endocrine regulation of compensatory growth. It is suggested that the increased concentrations of leptin and IGFBP-3 during pubertal development may act as physiological signals for the onset of puberty.
(South African Journal of Animal Science, 2000, 30(2): 155-163)
DOI：
10.1210/endo.137.2.8593808
发表时间：
1996
期刊：
Endocrinology.
影响因子：
--
作者：
Bucholtz,DC;Vidwans,NM;Herbosa,CG;Schillo,KK;Foster,DL
通讯作者：
Foster,DL
一种通过蛋白质印迹法检测胰岛素样生长因子结合蛋白的快速、非放射性方法。
DOI：
10.1210/endo.137.12.8940413
发表时间：
1996
期刊：
Endocrinology.
影响因子：
--
作者：
Fowlkes,JL;Serra,D
通讯作者：
Serra,D
影响因子：
3.6
作者：
Foster, DL;Nagatani, S
通讯作者：
Nagatani, S