Simmen R C, Simmen F A, Hofig A, Farmer S J, Bazer F W
Department of Animal Science, University of Florida, Gainesville 32611-0701.
Endocrinology. 1990 Nov;127(5):2166-74. doi: 10.1210/endo-127-5-2166.
The present studies were undertaken to define potential regulation of endometrial insulin-like growth factor-I (IGF-I) synthesis and secretion by steroid hormones and to correlate conceptus- and serum-derived estrogens with these events. Four experimental groups of gilts were studied: 1) prepubertal gilts administered estradiol (E) and/or progesterone (P4) daily for up to 15 days; 2) mature gilts ovariectomized (ovx) on day 2 of the estrous cycle, and then administered E, P4, or E plus P4 from days 4-11 after estrus; 3) unilaterally pregnant gilts on day 12 or 16 after the onset of estrus; and 4) cyclic gilts administered E on day 11 and hysterectomized 1, 6, 12, or 24 h after E. IGF-I mRNA was measured by blot hybridization of total cellular RNAs, while a specific RIA was used to quantitate levels of tissue and uterine luminal fluid (ULF) IGF-I. In prepubertal gilts, E or P4 increased uterine IGF-I mRNA levels and IGF-I protein. Mature, ovx gilts treated with E, P4, or E plus P4 had increased levels of endometrial IGF-I mRNAs and protein and luminal IGF-I. The magnitude of E or P4 induction was comparable and was not additive. Gravid horns on day 12 had higher amounts of IGF-I in ULF compared to day 12 nongravid horns or day 16 gravid and nongravid horns. However, no significant differences in the amounts of endometrial IGF-I mRNA and tissue IGF-I content between horns on each day were detected. Acute treatment of cyclic gilts (day 11) with E increased levels of endometrial IGF-I mRNAs and luminal IGF-I 1 h after treatment. The effect of E was transient and was reversed within 24 h of E injection. IGF-II and IGF-binding protein-2 mRNAs were regulated by E and P4 distinct from IGF-I mRNAs. These results indicate that E and P4 are involved in the normal regulation of uterine IGF-I synthesis and/or secretion. However, the relative contributions of serum and conceptus-derived estrogens in these processes during the preimplantation period in the pig remain to be defined.
本研究旨在确定甾体激素对子宫内膜胰岛素样生长因子-I（IGF-I）合成和分泌的潜在调节作用，并将来自胚胎和血清的雌激素与这些事件联系起来。对四组实验母猪进行了研究：1）青春期前母猪，每天给予雌二醇（E）和/或孕酮（P4），持续15天；2）在发情周期第2天进行卵巢切除（ovx）的成年母猪，然后在发情后第4 - 11天给予E、P4或E加P4；3）发情开始后第12天或第16天的单侧怀孕母猪；4）在第11天给予E并在注射E后1、6、12或24小时进行子宫切除的周期性发情母猪。通过对总细胞RNA进行印迹杂交来测量IGF-I mRNA，同时使用特异性放射免疫分析法（RIA）定量组织和子宫腔液（ULF）中IGF-I的水平。在青春期前母猪中，E或P4可增加子宫IGF-I mRNA水平和IGF-I蛋白。用E、P4或E加P4处理的成年、卵巢切除母猪，其子宫内膜IGF-I mRNA和蛋白水平以及腔液IGF-I均升高。E或P4诱导的幅度相当，且无叠加效应。与第12天的非妊娠角或第16天的妊娠和非妊娠角相比，第12天妊娠角的ULF中IGF-I含量更高。然而，每天两角之间的子宫内膜IGF-I mRNA量和组织IGF-I含量未检测到显著差异。对周期性发情母猪（第11天）急性给予E可使子宫内膜IGF-I mRNA水平和腔液IGF-I在处理后1小时升高。E的作用是短暂的，在注射E后24小时内恢复。IGF-II和IGF结合蛋白-2 mRNA受E和P4调节，与IGF-I mRNA不同。这些结果表明，E和P4参与子宫IGF-I合成和/或分泌的正常调节。然而，在猪的植入前期，血清和胚胎来源的雌激素在这些过程中的相对贡献仍有待确定。
