Pregnancy alters cardiac receptor afferent discharge in rats.
Pregnancy alters cardiac receptor afferent discharge in rats.
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怀孕改变大鼠心脏受体传入放电。
DOI：
10.1152/ajpregu.2000.278.1.r149
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Hodgson,TM
中科院分区：
文献类型：
--
作者：
Hines,T;Hodgson,TM
刺激心脏受体(CR)的反射效应在妊娠大鼠中减弱。我们通过测量右心房压力(RAP)升高的单纤维活动来测试在妊娠期间是否减少了CR传入放电，这是因为麻醉的妊娠和处女大鼠失去了窦主动脉神经。从右侧颈迷走神经的细丝中分离出单纤维活性。记录心房注射生理盐水(25-300μ，L)后CR放电、RAP和动脉压的变化。两组间静息RAP相似，孕鼠自发CR放电(1.95±0.21 Hz)与处女大鼠低频(LF)受体自发放电(1.30±0.2 Hz)相似。在未怀孕的处女鼠，CR的一部分(24%)有较高频率(9.91±1.19赫兹)的自发放电。在刺激过程中，妊娠大鼠的RAP水平和CR放电增加显著增加，但CR活动聚集在一个LF放电范围内。因此，妊娠可能通过增加刺激阈值或通过选择性地灭活一部分HF放电受体来降低CR传入神经元的活性。
Reflex effects of cardiac receptor (CR) stimulation are attenuated in pregnant rats. We tested whether CR afferent discharge is reduced during pregnancy by measuring single fiber activity in response to increases in right atrial pressure (RAP) in anesthetized pregnant and virgin rats with sinoaortic denervation. Single fiber activity was isolated from fine filaments of the right cervical vagus nerve. Changes in CR discharge, RAP, and arterial pressure were recorded in response to atrial saline injections (25–300 μl). Resting RAP was similar between groups, and spontaneous CR discharge was similar in pregnant rats (1.95 ± 0.21 Hz) and in low-frequency (LF) receptors in virgin rats (1.30 ± 0.2 Hz). In virgin, but not pregnant rats, a subset (24%) of CR had higher-frequency (HF) spontaneous discharge (9.91 ± 1.19 Hz). During stimulation, the level of RAP above which CR firing increased was significantly higher in pregnant rats, but CR activity was clustered into an LF discharge range. Thus gestation appears to reduce the activity of CR afferents, possibly by increasing stimulus threshold or by selective inactivation of a subset of HF discharging receptors.