Schulz C, Lehnert H
Department of Endocrinology and Metabolism, University Hospital of the Otto von Guericke University, Magdeburg, Germany.
Neuroendocrinology. 1996 May;63(5):454-8. doi: 10.1159/000127071.
In the present study the effects of different doses of corticotropin-releasing factor (CRF) and the CRF antagonist alpha-helical CRF on locus coeruleus (LC) neurons were studied in anesthetized male Wistar rats. To monitor the release of noradrenaline (NA) and its metabolite 3-methoxy-4-hydroxyphenylethylene glycol (MHPG), a microdialysis probe was implanted into the parietal cortex, a major projection area of the LC. Saline, 0.17, 0.51 nmol CRF and a combination of 5.1 nmol alpha-helical CRF and 0.51 nmol CRF were applied to the LC via a fused silica capillary. While both doses of CRF augmented NA in parietal cortex dialysates (0.51 nmol CRF: from 0.0206 to 0.0266 pmol/sample; 0.17 nmol CRF: from 0.0147 to 0.0170 pmol/sample), saline did not affect NA concentration. The metabolite MHPG also increased, but in a more prolonged time course. The antagonist alpha-helical CRF attenuated the CRF effects. The increase of extraneuronal NA concentration monitored in the cortical samples indicates an augmented depolarization rate of noradrenergic LC neurons. This clearly demonstrates the activation of these neurons by CRF, suggesting physiological interactions of CRF and noradrenergic neurons.
在本研究中，我们在麻醉的雄性Wistar大鼠中研究了不同剂量的促肾上腺皮质激素释放因子（CRF）和CRF拮抗剂α-螺旋CRF对蓝斑（LC）神经元的影响。为了监测去甲肾上腺素（NA）及其代谢产物3-甲氧基-4-羟基苯乙二醇（MHPG）的释放，将微透析探针植入顶叶皮质，这是LC的一个主要投射区域。通过熔融石英毛细管将生理盐水、0.17、0.51 nmol CRF以及5.1 nmol α-螺旋CRF与0.51 nmol CRF的组合应用于LC。两种剂量的CRF均增加了顶叶皮质透析液中的NA（0.51 nmol CRF：从0.0206增至0.0266 pmol/样本；0.17 nmol CRF：从0.0147增至0.0170 pmol/样本），而生理盐水未影响NA浓度。代谢产物MHPG也增加，但时间过程更长。拮抗剂α-螺旋CRF减弱了CRF的作用。在皮质样本中监测到的细胞外NA浓度的增加表明去甲肾上腺素能LC神经元的去极化速率增加。这清楚地证明了CRF对这些神经元的激活，提示CRF与去甲肾上腺素能神经元之间存在生理相互作用。
