Otten Winfried, Kanitz Ellen, Tuchscherer Margret, Schneider Falk, Brüssow Klaus-Peter
Behavioural Physiology, Research Institute for the Biology of Farm Animals, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
Theriogenology. 2004 Jun;61(9):1649-59. doi: 10.1016/j.theriogenology.2003.09.009.
The effect of adrenocorticotropic hormone (ACTH) administration on plasma cortisol concentrations was determined in pregnant gilts and their fetuses. In a first experiment, 100 IU ACTH (Synacthen Depot) was administered intramuscularly to the gilts every second day from Days 49 to 75 of gestation. ACTH injections were carried out at 08:00 h and, thereafter, 10 blood samples were taken within the following 8h via jugular catheters. Blood samples were analysed for plasma cortisol concentrations, and results were compared with values from animals which were treated with physiological saline and untreated animals (blood sampling only). The values for plasma cortisol concentrations increased until 3h after ACTH applications to a mean maximum level of 276.5+/-17.2 nmol/l in the whole 4-week stimulation period. Plasma cortisol levels did not return to pre-treatment values within the 8 h post-injection. No differences in cortisol levels were found between the physiological saline and untreated control, and no habituation of the adrenocortical response to ACTH was found during the 4-week stimulation period. In a second experiment, 100 IU ACTH were administered to pregnant gilts at gestation Day 65. After 3 h, fetuses were recovered under general anaesthesia and blood samples were taken from the umbilical vein, artery, and, after decapitation, from periphery. Application of ACTH to the sows significantly increased their plasma cortisol concentrations (P<0.001), and also increased plasma cortisol concentrations in peripheral blood samples from the fetuses (P=0.09) and in the umbilical vein (P<0.001) and artery (P<0.01), respectively. Plasma ACTH concentrations did not differ in fetuses from ACTH-treated or control sows. The results show that in gilts the adrenocortical response to an exogenous application of Synacthen Depot is consistent over time during mid-gestation. Furthermore, cortisol but not ACTH levels were increased in fetuses from ACTH-treated sows, indicating that maternal cortisol can cross the placenta during mid-gestation. The stimulation of maternal cortisol release through exogenous ACTH with subsequent elevation of fetal cortisol levels is, therefore, a useful approach for studying effects of elevated maternal glucocorticoids in prenatal stress studies in pigs.
研究了促肾上腺皮质激素（ACTH）给药对妊娠后备母猪及其胎儿血浆皮质醇浓度的影响。在第一个实验中，从妊娠第49天至75天，每隔一天给后备母猪肌肉注射100 IU ACTH（长效合成促皮质素）。ACTH注射在08:00进行，之后，在接下来的8小时内通过颈静脉导管采集10份血样。分析血样中的血浆皮质醇浓度，并将结果与用生理盐水处理的动物和未处理动物（仅采血）的值进行比较。在整个4周的刺激期内，血浆皮质醇浓度在ACTH给药后3小时内升高至平均最高水平276.5±17.2 nmol/l。注射后8小时内，血浆皮质醇水平未恢复到治疗前值。生理盐水处理组和未处理对照组之间的皮质醇水平无差异，且在4周刺激期内未发现肾上腺皮质对ACTH的反应出现适应性变化。在第二个实验中，在妊娠第65天给妊娠后备母猪注射100 IU ACTH。3小时后，在全身麻醉下取出胎儿，并从脐静脉、动脉采血，断头后从外周采血。给母猪注射ACTH显著提高了它们的血浆皮质醇浓度（P<0.001），也分别提高了胎儿外周血样（P=0.09）、脐静脉（P<0.001）和动脉（P<0.01）中的血浆皮质醇浓度。来自ACTH处理母猪或对照母猪的胎儿血浆ACTH浓度没有差异。结果表明，在妊娠中期，后备母猪对外源性长效合成促皮质素的肾上腺皮质反应随时间保持一致。此外，ACTH处理母猪的胎儿中皮质醇水平升高而ACTH水平未升高，这表明母体皮质醇在妊娠中期可以穿过胎盘。因此，通过外源性ACTH刺激母体皮质醇释放并随后提高胎儿皮质醇水平，是研究母体糖皮质激素升高对猪产前应激影响的一种有用方法。
