Krishna B R, King R G, Brennecke S P
Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.
J Perinat Med. 1992;20(3):197-202. doi: 10.1515/jpme.1992.20.3.197.
The aim of this study was to examine the role of calcium in the release of acetylcholine (ACh) from the fetal circulation of the dually perfused human placenta. The viability of this preparation was demonstrated; Glucose consumption and lactate production (as sums of both the fetal and maternal values) over the 4 h perfusion period were 13.9 +/- 4.2 mmol/kg/h (mean +/- SEM, n = 7) and 15.1 +/- 2.0 mmol/kg/h (n = 13) respectively. Mean pH levels of the fetal and maternal effluent perfusates were 7.26 +/- 0.02 (n = 5) and 7.32 +/- 0.01 (n = 5). None of these parameters varied significantly from 1 to 4 h of perfusion. ACh output into the fetal vessels after 1 h of perfusion was 0.31 +/- 0.02 nnmol/min/g wt weight (n = 5) in the presence of physostigmine (2.7 uM) and did not vary significantly from 1 to 4 h of perfusion. Perfusion with Ca+(+)-free Krebs solution and 2 mM EDTA (but not with Krebs in the absence of EDTA, or with both Ca++ and EDTA, or in the presence of 3.78 mM Ca++) for 60 min resulted in a significant reduction of ACh output in the fetal perfusate. Output in the former case was partially restored on subsequent perfusion with normal Krebs for 60 min. These results suggest ACh release in perfused human placenta lobules is at least partially Ca+(+)-dependent.
本研究的目的是探讨钙在双灌注人胎盘胎儿循环中乙酰胆碱（ACh）释放中的作用。已证实该制剂具有活力；在4小时灌注期内，葡萄糖消耗和乳酸产生（胎儿和母体值之和）分别为13.9±4.2 mmol/kg/h（平均值±标准误，n = 7）和15.1±2.0 mmol/kg/h（n = 13）。胎儿和母体流出灌注液的平均pH值分别为7.26±0.02（n = 5）和7.32±0.01（n = 5）。在灌注1至4小时期间，这些参数均无显著变化。在毒扁豆碱（2.7 μM）存在的情况下，灌注1小时后胎儿血管中的ACh输出量为0.31±0.02 nmol/min/g湿重（n = 5），在灌注1至4小时期间无显著变化。用无Ca++的Krebs溶液和2 mM EDTA灌注（但不用无EDTA的Krebs溶液，或同时用Ca++和EDTA，或在3.78 mM Ca++存在的情况下）60分钟，导致胎儿灌注液中ACh输出量显著降低。在前一种情况下，随后用正常Krebs溶液灌注60分钟，输出量部分恢复。这些结果表明，灌注人胎盘小叶中ACh的释放至少部分依赖于Ca++。
