Kotsampasi B, Balaskas C, Papadomichelakis G, Chadio S E
Laboratory of Anatomy and Physiology of Domestic Animals, Department of Animal Science and Aquaculture, Agricultural University of Athens, Athens, Greece.
Anim Reprod Sci. 2009 Aug;114(1-3):135-47. doi: 10.1016/j.anireprosci.2008.08.017. Epub 2008 Aug 19.
The nutritional status of females during pregnancy can have profound effects on the fetus reproductive system development that could affect the reproductive potential as later as in adulthood (fetal programming). The aim of the present study was to examine the effects of maternal nutrient restriction imposed during different periods of gestation on pituitary responsiveness at different ages postnatal and on Sertoli cell number in male offspring. Pregnant ewes were fed to 100% of Metabolizable Energy and Crude Protein requirements throughout pregnancy (Control) or to 50% from 0 to 30 (R1) or from 31 to 100 days of gestation (R2). Male lambs were selected and fed to appetite throughout the study. At 2, 5.5 and 10 months of age a GnRH challenge was conducted. At slaughter (10 months) testes were removed and examined histologically. Maternal undernutrition did not affect the time of the onset of puberty, defined as the first increase in plasma testosterone concentrations > or =1 ng/ml. The LH and FSH response to GnRH challenge did not differ between groups at 2 and 5.5 months but at 10 months of age a higher (P<0.05) FSH response was found in R2 group. Testes weight did not differ between groups at slaughter. Mean Sertoli cell number was significantly lower in animals of R2 group compared with Control (P<0.01). A smaller seminiferous tubules diameter was detected in R2 group (P<0.05), while the diameter of the lumen was similar in all groups. Collectively, these results provide clear evidence for a direct effect of nutrient restriction during pregnancy on Sertoli cell number in adulthood. The lower number of Sertoli cells is the most candidate factor for the higher pituitary activity through a reduction in the suppressive effect of inhibin.
孕期女性的营养状况会对胎儿生殖系统发育产生深远影响，这种影响甚至可能在成年后期影响生殖潜能（胎儿编程）。本研究的目的是探讨孕期不同阶段实施的母体营养限制对雄性后代出生后不同年龄垂体反应性以及支持细胞数量的影响。将怀孕母羊在整个孕期饲喂至可代谢能量和粗蛋白需求的100%（对照组），或在妊娠0至30天（R1）或31至100天（R2）饲喂至50%。在整个研究过程中选择雄性羔羊并按食欲喂养。在2、5.5和10月龄时进行GnRH刺激试验。在屠宰时（10月龄）取出睾丸并进行组织学检查。母体营养不足并未影响青春期开始的时间，青春期定义为血浆睾酮浓度首次升高至≥1 ng/ml。在2和5.5月龄时，各组对GnRH刺激的LH和FSH反应无差异，但在10月龄时，R2组的FSH反应更高（P<0.05）。屠宰时各组睾丸重量无差异。与对照组相比，R2组动物的平均支持细胞数量显著降低（P<0.01）。在R2组中检测到较小的生精小管直径（P<0.05），而所有组管腔直径相似。总体而言，这些结果为孕期营养限制对成年期支持细胞数量的直接影响提供了明确证据。支持细胞数量减少是通过降低抑制素的抑制作用导致垂体活性升高的最可能因素。
