Anticholinergic suppression of ovine fetal swallowing activity
Anticholinergic suppression of ovine fetal swallowing activity
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DOI：
10.1016/s0002-9378(97)70024-3
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发表时间：
1997-11-01
影响因子：
9.8
通讯作者：
Ross, MG
中科院分区：
文献类型：
--
作者：
Nijland, MJM;Chao, CR;Ross, MG
目的：胎儿吞咽作为液体吸收的主要途径，对羊水量的调节有重要作用，近期可达到500至1000 ml/天。近期绵羊胎儿吞咽活动主要发生在低电压皮层电活动。考虑到潜在的刺激改变皮层电活动，我们假设胎儿给药中枢作用胆碱能拮抗剂可用于调节胎儿吞咽活动。探讨胆碱能调制的吞咽活动，我们研究了胎儿吞咽和皮层电活动的中枢和外周胆碱能抑制硫酸阿托品。研究设计：单胎羊胎儿（n = 6）长期准备血管导管和甲状舌骨，颈，胸食管肌电图和双顶皮层电电极。在静脉注射硫酸阿托品（1 mg/kg）（1 ml 0.15 mol/L氯化钠）之前和之后2小时监测吞咽和皮层电活动。或者，在随后的一天，使用阿托品硝酸甲酯（3 mg/kg）进行相同的研究，阿托品硝酸甲酯是一种不能穿过血脑屏障的阿托品类似物。硫酸阿托品降低低电压皮层电活动（56% +/- 5%至14% +/- 4%），增加高压皮层电活动（40% +/- 5%至81% +/- 5%），不改变中间皮层电活动（4% +/- 1%至5% +/- 1%）。硫酸阿托品给药后，胎儿吞咽活动从每小时46 +/- 12次降低至12 +/- 2次。甲基硝酸阿托品对胎儿皮层电活动或吞咽活动均无明显影响。胎儿动脉压，血浆渗透压，pH值，Pco（2），和PO-2没有改变。结论：中枢胆碱能拮抗作用抑制低电压胎儿皮层电和吞咽活动在羊胎儿。探索自发或诱导胎儿吞咽的研究在得出吞咽活动变化的结论时，应考虑胎儿的行为状态。
OBJECTIVE: Fetal swallowing contributes importantly to amniotic fluid volume regulation as the primary route of fluid resorption, reaching 500 to 1000 ml/day near term. Near-term ovine fetal swallowing activity occurs predominantly during low-voltage electrocortical activity. In view of the potential to pharmacologically alter electrocortical activity, we hypothesized that fetal administration of a centrally acting cholinergic antagonist may be used to modulate fetal swallowing activity. To explore cholinergic modulation of swallowing activity, we examined fetal swallowing and electrocortical activity in response to central and peripheral cholinergic suppression by atropine sulfate.STUDY DESIGN: Singleton ovine fetuses (n = 6) were chronically prepared with vascular catheters and thyrohyoid, nuchal, and thoracic esophageal electromyogram and biparietal electrocortical electrodes. Swallowing and electrocortical activity were monitored for 2 hours before and after intravenous injection (1 ml of 0.15 mol/L sodium chloride) of atropine sulfate (1 mg/kg). Or, a subsequent day an identical study was performed with use off atropine methyl nitrate (3 mg/kg), an atropine analog that does not cross the blood-brain barrier.RESULTS: Atropine sulfate decreased low-voltage electrocortical activity (56% +/- 5% to 14% +/- 4%), increased high-voltage electrocortical activity (40% +/- 5% to 81% +/- 5%), and did not change intermediate electrocortical activity (4% +/- 1% to 5% +/- 1%). Fetal swallowing activity decreased from 46 +/- 12 to 12 +/- 2 swallows per hour after atropine sulfate administration. Atropine methyl nitrate had no discernible effect on either fetal electrocortical or swallowing activity. Fetal arterial pressure, plasma osmolality, pH, Pco(2), and Po-2 did not change.CONCLUSIONS: Central cholinergic antagonism suppresses low-voltage fetal electrocortical and swallowing activity in the ovine fetus. Studies exploring spontaneous or induced fetal swallowing should consider the behavioral state of the fetus when conclusions are drawn about changes in the swallowing activity.