Nicol M B, Hirst J J, Walker D W
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Neurosci Lett. 1998 Sep 4;253(2):111-4. doi: 10.1016/s0304-3940(98)00627-2.
The effect of infusing the neuroactive steroids pregnanolone and iso-pregnanolone on somatosensory evoked potentials (SEP) and electrocortical (ECoG) activity was studied in unanaesthetised fetal sheep, 130-135 days gestation. Intravenous infusion of pregnanolone (6 mg/kg per h) significantly increased the proportion of high voltage ECoG (56.1+/-4.8% vs. control 43.5+/-3.2%, P < 0.05), and decreased low voltage ECoG (43.9+/-4.8% vs. control 56.6+/-3.2%, P < 0.05). Pregnanolone treatment decreased the amplitude of the N25 peak of the SEP (89.9+/-2.8% of control, P < 0.05) evoked following stimulation of the skin of the upper lip. In contrast, iso-pregnanolone treatment had no effect on ECoG activities, or on the amplitude and latency of peaks in the SEP. We conclude that 3alpha-hydroxy pregnane steroids are active at GABA(A) receptors in fetal sheep and can modulate sleep/wake activity before birth.
在妊娠130 - 135天的未麻醉胎羊中，研究了注入神经活性甾体孕烷醇酮和异孕烷醇酮对体感诱发电位（SEP）和皮层电图（ECoG）活动的影响。静脉输注孕烷醇酮（6毫克/千克/小时）显著增加了高电压ECoG的比例（56.1±4.8%对对照组43.5±3.2%，P < 0.05），并降低了低电压ECoG的比例（43.9±4.8%对对照组56.6±3.2%，P < 0.05）。孕烷醇酮处理降低了刺激上唇皮肤后诱发的SEP的N25峰的振幅（为对照组的89.9±2.8%，P < 0.05）。相比之下，异孕烷醇酮处理对ECoG活动或SEP中各峰的振幅和潜伏期均无影响。我们得出结论，3α - 羟基孕烷甾体在胎羊的GABA(A)受体上具有活性，并且可以在出生前调节睡眠/觉醒活动。
