Xu Shuang, Guo Shiyu, Jiang Xinhong, Umezawa Teruyasu, Hisamitsu Tadashi
Department of Physiology, School of Medicine, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
Neurosci Lett. 2005 Aug 5;383(3):231-5. doi: 10.1016/j.neulet.2005.04.033.
To explore the potential role of norepinephrine (NE) and nitric oxide (NO) in activities of rat hypothalamus arginine vasopressin (AVP) neurons in response to immune challenge, we observed the effect of prazosin, an antagonist of alpha1-adrenergic receptor, and the specific nitric oxide synthase (NOS) inhibitor N(w)nitro-L-arginine-methylester (L-NAME) on the Fos expression in AVP neurons induced by systemic lipopolysaccharide (LPS) using double immunohistochemistry. Intravenous (i.v.) injection of LPS induced Fos expression in AVP neurons mainly in the hypothalamus paraventricular nucleus (PVN) and in the supraoptic nucleus (SON). The percentage of Fos-positive AVP neurons was dose-dependent. Pretreatment with prazosin (5 mg/kg) effectively suppressed the Fos expression induced by LPS (5 microg/kg), whereas L-NAME (30 mg/kg) did not influence the Fos expression in the AVP neurons induced by LPS (0.25, 0.5, 1, 5 microg/kg). Our results suggest that the activation of central AVP neurons caused by systemic LPS may be mediated by NE through alpha1-adrenergic receptors, but could not be changed by NO.
为探讨去甲肾上腺素（NE）和一氧化氮（NO）在大鼠下丘脑精氨酸血管加压素（AVP）神经元对免疫刺激反应活动中的潜在作用，我们采用双重免疫组化法观察了α1肾上腺素能受体拮抗剂哌唑嗪和特异性一氧化氮合酶（NOS）抑制剂N（ω）-硝基-L-精氨酸甲酯（L-NAME）对全身注射脂多糖（LPS）诱导的AVP神经元中Fos表达的影响。静脉注射LPS可诱导AVP神经元中Fos表达，主要位于下丘脑室旁核（PVN）和视上核（SON）。Fos阳性AVP神经元的百分比呈剂量依赖性。哌唑嗪（5mg/kg）预处理可有效抑制LPS（5μg/kg）诱导的Fos表达，而L-NAME（30mg/kg）对LPS（0.25、0.5、1、5μg/kg）诱导的AVP神经元中Fos表达无影响。我们的结果表明，全身LPS引起的中枢AVP神经元激活可能由NE通过α1肾上腺素能受体介导，但不受NO影响。
