An energy-rich diet causes rumen papillae proliferation associated with more IGF type 1 receptors and increased plasma IGF-1 concentrations in young goats
An energy-rich diet causes rumen papillae proliferation associated with more IGF type 1 receptors and increased plasma IGF-1 concentrations in young goats
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DOI：
10.1093/jn/134.1.11
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发表时间：
2004-01-01
影响因子：
4.2
通讯作者：
Voigt, J
中科院分区：
文献类型：
--
作者：
Shen, ZM;Seyfert, HM;Voigt, J
我们验证了这样一种假设，即日粮能量依赖性的瘤胃乳头大小的变化伴随着全身性胰岛素样生长因子(IGF)-1浓度和瘤胃乳头IGF-1受体(IGF-1R)的相应变化。将24只青年公羊随机分为两组(n=12)，分别饲喂高水平(HL)代谢能[1200kJ/(kg(0.75)d)]和低水平(LL)[500kJ/(kg(0.75)d)]日粮42d，两组瘤胃总SCFA浓度无显著差异，但HL组丁酸摩尔比例提高70%(P<；0.05)。HL组瘤胃、腹侧瘤胃囊和腹侧盲囊组织中乳头的长度和宽度均大于对照组(P<；0.05)，表面积比对照组大50~100%(P<；0.05)。对阿米洛利敏感的Na+跨瘤胃上皮转运，HL组高于LL组(P<；0.05)。此外，HL组血浆IGF-1浓度约为LL组的两倍(P<；0.05)，瘤胃上皮IGF-1R的最大结合量也高于LL组(P<；0.05)。在瘤胃乳头中检测到IGF-1R和IGF-1mRNA，但不受日粮处理的影响。体外培养的瘤胃上皮细胞经胰岛素样生长因子-1(25或50µg/L)处理后，其DNA合成和细胞增殖能力均显著高于不加胰岛素样生长因子-1组(P<0.05)。因此，依赖能量的日粮瘤胃形态和功能的变化伴随着系统LGF-1和瘤胃LGF-1R的相应变化。
We tested the hypothesis that the dietary energy-dependent alterations of the rumen papillae size are accompanied by corresponding changes in systemic insulin-like growth factor (IGF)-1 concentration and in rumen papillary IGF type 1 receptors (IGF-1R). Young male goats (n = 24) were randomly allocated to two groups (n = 12) and fed a high level (HL) metabolizable energy [1200 kJ/(kg(0.75.)d)] or a low level (LL) [500 kJ/(kg(0.75.)d)] diet for 42 d. The concentration of ruminal total SCFA did not differ between the groups, but the molar proportion of butyric acid was enhanced by 70% in the HL group (P < 0.05). Both the length and width of the papillae were greater (P < 0.05) in the HL group, and the surface was 50-100% larger (P < 0.05) in the tissue sampled from the artrium ruminis, the ventral ruminal sac and the ventral blind sac. Transport of Na+ across the rumen epithelium, which is amiloride sensitive, was higher (P < 0.05) in the HL than in the LL group. Furthermore, the plasma IGF-1 concentration was about twofold higher in the HL group (P < 0.05), and the maximal rumen epithelial IGF-1 R binding was also higher in the HL (P < 0.05) than in the LL group. IGF-1 R mRNA and IGF-1 mRNA were detected in rumen papillae; however, they were unaffected by dietary treatments. DNA synthesis and cell proliferation of cultured rumen epithelial cells were higher (P < 0.05) after IGF-1 treatment (25 or 50 mug/L) compared with those in the medium without IGF-1. Thus dietary energy-dependent alterations of rumen morphology and function are accompanied by corresponding changes in systemic lGF-1 and ruminal lGF-1R.