McMillen I C, Nowak R, Walker D W, Young I R
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Am J Physiol. 1990 Jan;258(1 Pt 2):R284-7. doi: 10.1152/ajpregu.1990.258.1.R284.
We have investigated the effect of pinealectomy of the pregnant ewe on the 24-h pattern of fetal breathing activity during late gestation. Fetal breathing movements were recorded during 24-h periods on 18 occasions in 5 pinealectomized ewes and on 24 occasions in 6 pineal-intact ewes between 120 and 145 days gestation. All ewes were fed once daily between 1000 and 1300 h and were kept under a light-dark cycle 12:12 h. There was no significant difference in the mean hourly incidence of fetal breathing movements between the pineal-intact (27.2 +/- 0.5 min/h) and pinealectomized (25.5 +/- 0.6 min/h) groups. However, there was a significant difference in the 24-h profiles of fetal breathing movements in the two groups. The peak incidence of fetal breathing occurred between 1900 and 2000 h in the pineal-intact ewes and between 1200 and 1300 h in the pinealectomized ewes. We conclude that maternal pinealectomy alters the daily pattern of a fetal behavioral pattern and that maternal melatonin may therefore provide the fetus with information about time of day.
我们研究了妊娠母羊松果体切除对妊娠后期胎儿呼吸活动24小时模式的影响。在妊娠120至145天期间，对5只松果体切除的母羊进行了18次24小时的胎儿呼吸运动记录，对6只松果体完整的母羊进行了24次记录。所有母羊每天在1000至1300时喂食一次，并保持在12:12小时的明暗周期下。松果体完整组（27.2±0.5分钟/小时）和松果体切除组（25.5±0.6分钟/小时）之间胎儿呼吸运动的平均每小时发生率没有显著差异。然而，两组胎儿呼吸运动的24小时曲线存在显著差异。松果体完整的母羊胎儿呼吸的高峰发生率出现在1900至2000时之间，而松果体切除的母羊则出现在1200至1300时之间。我们得出结论，母体松果体切除会改变胎儿行为模式的日常模式，因此母体褪黑素可能为胎儿提供有关一天中时间的信息。
