OXYTOCIN RELEASE FOLLOWING OSMOTIC ACTIVATION OF OXYTOCIN NEURONS IN PARAVENTRICULAR AND SUPRAOPTIC NUCLEI
OXYTOCIN RELEASE FOLLOWING OSMOTIC ACTIVATION OF OXYTOCIN NEURONS IN PARAVENTRICULAR AND SUPRAOPTIC NUCLEI
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DOI：
10.1113/jphysiol.1978.sp012293
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发表时间：
1978-01-01
影响因子：
5.5
通讯作者：
FORSLING, ML
中科院分区：
文献类型：
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作者：
BRIMBLE, MJ;DYBALL, REJ;FORSLING, ML
记录了总共35个逆向识别的神经元在室旁核（PV）和视上核（SO）的麻醉泌乳大鼠。在记录期间，通过注射NaCl、LiCl或甘露醇的高渗溶液，血浆渗透压升高12 m-osmole/kg。9个PV神经元（平均放电率4.2 ± 0.01）。1.0（SE）尖峰/秒）被归类为催产素细胞，因为它们在反射性排乳之前产生一系列活动。这些都没有表现出爆发（阶段性）的发射模式。10个PV神经元（平均放电率1.8 ±. 0.2在注射高渗氯化钠之前或之后相性地放电，并被归类为加压素细胞。剩余的6个PV电池（平均放电率1.6 ± 1.5）。0.9峰值/秒）显示没有与乳汁排出相关的爆发性放电，并且没有阶段性放电。通过注射高渗NaCl增加血浆渗透压使PV催产素细胞的平均放电率增加至7.0 ± 0.01。1.0峰值/秒PV核中的血管加压素细胞的反应性低得多，注射后的平均放电率为2.9 ± 1.5。0.4峰值/秒第3组PV神经元无反应。血浆催产素浓度（通过放射免疫测定法测定）从2.1 . ±. 0.3对照期μ U[微单位]/ml至10.9 ±。2.8μ U/ml。腹膜内注射1 ml 1.5 M NaCl后30分钟，2.8在注射第二次1 ml 1.5M NaCl后，催产素和加压素神经元在SO核的血浆渗透压的增加注射后的高渗溶液氯化锂或甘露醇的反应是类似的观察时，血浆渗透压升高NaCl。神经垂体系统中的催产素和加压素细胞都对血浆的渗透压而不是对Na+或Cl-浓度有反应。催产素细胞的渗透激活释放足够的催产素以增加其血浆浓度。SO核和PV核之间可能存在功能差异。
Recordings were made from a total of 35 antidromically identified neurons in the paraventricular (PV) and supraoptic (SO) nuclei of urethane-anesthetized lactating rats. During recording plasma osmotic pressure was raised by 12 m-osmole/kg by injection of hypertonic solutions of NaCl, LiCl, or mannitol. Nine PV neurons (mean firing rate 4.2 .+-. 1.0 (SE) spikes/s) were classified as oxytocin cells because they gave a burst of activity before reflex milk ejections. None of these showed a bursting (phasic) firing pattern. Ten PV neurons (mean firing rate 1.8 .+-. 0.2 spikes/s) fired phasically either before or after injection of hypertonic NaCl and were classified as vasopressin cells. The remaining 6 PV cells (mean firing rate 1.6 .+-. 0.9 spikes/s) showed no bursts of firing related to milk ejection and did not fire phasically. Increasing plasma osmotic pressure by injection of hypertonic NaCl increased the mean firing rate of PV oxytocin cells to 7.0 .+-. 1.0 spikes/s. Vasopressin cells in the PV nucleus were much less responsive and the mean firing rate after injection was 2.9 .+-. 0.4 spikes/s. The 3rd group of PV neurons was unresponsive. Plasma oxytocin concentration (determined by radioimmunoassay) increased from 2.1 .+-. 0.3 .mu.U[microunits]/ml in the control period to 10.9 .+-. 2.8 .mu.U/ml. Thirty minutes after i.p. injection of 1 ml 1.5 M NaCl and to 14.8 .+-. 2.8 .mu.U/ml following injection of a 2nd 1 ml 1.5 M NaCl. The responses of oxytocin and vasopressin neurons in the SO nucleus to an increase in plasma osmotic pressure following injections of hypertonic solutions of LiCl or mannitol were similar to those observed when plasma osmotic pressure was raised by NaCl. Both oxytocin and vasopressin cells in the neurohypophyseal system are responsive to the osmotic pressure of the blood plasma rather than to Na+ or Cl- concentration. Osmotic activation of oxytocin cells releases sufficient oxytocin to increase its plasma concentration. There may be a functional difference between the SO and PV nuclei.