Arancibia S, Assenmacher I
Laboratoire de Neurobiologie Endocrinologique, UA 1197 du CNRS, Université de Montpellier II, France.
C R Seances Soc Biol Fil. 1987;181(3):323-31.
The concentrations of TRH in the cerebrospinal fluid (CSF) of the 3rd ventricle were measured with push-pull cannulae in 12 conscious rats. In the basal state the level of TRH in 15 min perfusion samples (210 microliters) were low (2.69 +/- 0.05 pg) and mostly undetectable with the RIA available. However, 70 to 80 min after exposure of the rats to cold (4 degrees C) a short lived but significant rise of TRH was measured in all animals. Post cold peaks amounted to 5.15 +/- 0.5 pg/15 min (p less than 0.001 vs baseline levels). This cold response to CSF TRH was influenced neither by pretreatment of rats with the alpha-adrenergic blocker phentolamine, administered i.p. (40 mg/kg) or i. c. v. (10(-5) M) 1 h before cold exposure, nor by i. c. v. infusion of the alpha 1-adrenergic blocker prazosin (10(-5) M). In rats receiving the blockers the post-cold TRH peaks were 6.76 +/- 1.61 pg/15 min and 5.70 +/- 0.70 pg/15 min, respectively. The possible origin of CSF TRH and the resistance of its cold stimulation to alpha-adrenergic blockers, compared to TRH released into the median eminence are discussed.
采用推挽式套管法，对12只清醒大鼠第三脑室脑脊液（CSF）中的促甲状腺激素释放激素（TRH）浓度进行了测定。在基础状态下，15分钟灌注样本（210微升）中的TRH水平较低（2.69±0.05皮克），使用现有的放射免疫分析法大多检测不到。然而，将大鼠暴露于寒冷环境（4℃）70至80分钟后，所有动物的TRH均出现短暂但显著的升高。冷刺激后的峰值达到5.15±0.5皮克/15分钟（与基线水平相比，p＜0.001）。这种对脑脊液TRH的冷反应，既不受在冷暴露前1小时腹腔注射（40毫克/千克）或脑室内注射（10⁻⁵摩尔）α-肾上腺素能阻滞剂酚妥拉明预处理大鼠的影响，也不受脑室内输注α₁-肾上腺素能阻滞剂哌唑嗪（10⁻⁵摩尔）的影响。接受阻滞剂的大鼠冷刺激后TRH峰值分别为6.76±1.61皮克/15分钟和5.70±0.70皮克/15分钟。本文还讨论了脑脊液TRH的可能来源，以及与释放到正中隆起的TRH相比，其冷刺激对α-肾上腺素能阻滞剂的抵抗性。
