Alvaro Ruben E, Hasan Shabih U, Chemtob Sylvain, Qurashi Mansour, Al-Saif Saif, Rigatto Henrique
Departments of Pediatrics, Physiology and Reproductive Medicine, University of Manitoba, WR004--Women's Hospital, 735 Notre Dame Avenue, Winnipeg, Man., Canada R3E 0L8.
Respir Physiol Neurobiol. 2004 Nov 30;144(1):35-44. doi: 10.1016/j.resp.2004.08.006.
We have previously observed that the infusion of a placental extract inhibits breathing movements in fetal sheep, suggesting that a placental factor may be responsible for the inhibition of fetal breathing. Our preliminary results suggested that a small peptide or a substance bound to a peptide was likely responsible for this inhibition. Since prostaglandins are found in high concentrations in the placenta, it is possible that they may be responsible for the inhibition of breathing observed with the placental extract. We hypothesized that if prostaglandins were the active factors in the placental extract, then inhibition of the production of placental prostaglandins should eliminate the activity of the extract. We infused untreated and indomethacin/ASA-treated placental extracts into the carotid artery of eight chronically instrumented fetal sheep continuously over 3 h. The concentration of all prostaglandins measured in the untreated placental extracts were significantly higher than in the indomethacin/ASA-treated extracts. Only the infusion of the untreated placental extract induced a significant decreased in the incidence of fetal breathing. Fetal plasma prostaglandins increased significantly only with the infusion of the untreated placental extracts. These findings suggest that the inhibition of breathing observed with the placental extract is likely related to prostaglandins.
我们之前观察到，输注胎盘提取物会抑制胎羊的呼吸运动，这表明可能有一种胎盘因子导致了胎儿呼吸的抑制。我们的初步结果表明，一种小肽或与肽结合的物质可能是这种抑制作用的原因。由于前列腺素在胎盘中的浓度很高，所以它们有可能是导致胎盘提取物所观察到的呼吸抑制的原因。我们推测，如果前列腺素是胎盘提取物中的活性因子，那么抑制胎盘前列腺素的产生应该会消除提取物的活性。我们将未经处理的以及用吲哚美辛/阿司匹林处理过的胎盘提取物连续3小时持续输注到8只长期植入仪器的胎羊的颈动脉中。在未经处理的胎盘提取物中测得的所有前列腺素的浓度均显著高于用吲哚美辛/阿司匹林处理过的提取物。只有输注未经处理的胎盘提取物才会导致胎儿呼吸发生率显著降低。只有在输注未经处理的胎盘提取物时，胎儿血浆中的前列腺素才会显著增加。这些发现表明，胎盘提取物所观察到的呼吸抑制可能与前列腺素有关。
