Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
Brain Res. 2012 Nov 5;1483:1-12. doi: 10.1016/j.brainres.2012.08.028. Epub 2012 Sep 6.
Arginine-vasopressin (AVP) is a nonapeptide of hypothalamic origin that has been shown to exert many important cognitive and physiological functions in neurons and terminals of both the central and peripheral nervous system (CNS and PNS). Here we report for the first time that AVP induced an increase in intracellular Ca²⁺ concentration (Ca²⁺) in non-neuronal cells isolated from the rat dorsal root ganglion (DRG) and cultured in vitro. The ratiometric Ca²⁺ measurements showed that AVP evoked Ca²⁺ responses in the non-neuronal cells and these concentration-dependent (100 pM to 1 μM) responses increased with days in vitro in culture, reaching a maximum amplitude after 4-5 day. Immunostaining by anti-S-100 antibody revealed that more than 70% of S-100 positive cells were AVP-responsive, indicating that glial cells responded to AVP and increased their Ca²⁺. The responses were inhibited by depletion of the intracellular Ca²⁺ stores or in the presence of inhibitors of phospholipase C, indicating a metabotropic response involving inositol trisphosphate, and were mediated by the V₁ subclass of AVP receptors, as evidenced by the use of the specific blockers for V₁ and OT receptors, (d(CH₂)₅¹,Tyr(Me)²,Arg⁸)-Vasopressin and (d(CH₂)₅¹,Tyr(Me)²,Thr⁴,Orn⁸,des-Gly-NH₂⁹)-Vasotocin, respectively. V(1a) but not V(1b) receptor mRNA was expressed sustainably through the culture period in cultured DRG cells. These results suggest that AVP modulates the activity of DRG glial cells via activation of V(1a) receptor.
精氨酸加压素（AVP）是一种源自下丘脑的九肽，已被证明在中枢和外周神经系统（CNS 和 PNS）的神经元和末梢中发挥许多重要的认知和生理功能。在这里，我们首次报道 AVP 诱导分离自大鼠背根神经节（DRG）并在体外培养的非神经元细胞内细胞内 Ca²⁺浓度（Ca²⁺）增加。比率 Ca²⁺测量表明，AVP 可诱发非神经元细胞中的 Ca²⁺反应，这些浓度依赖性（100 pM 至 1 μM）反应随着体外培养天数的增加而增加，在 4-5 天后达到最大幅度。用抗 S-100 抗体进行免疫染色显示，超过 70%的 S-100 阳性细胞对 AVP 有反应，表明胶质细胞对 AVP 有反应并增加了它们的 Ca²⁺。细胞内 Ca²⁺储存耗尽或存在磷脂酶 C 抑制剂时，反应被抑制，表明存在涉及三磷酸肌醇的代谢反应，并且通过使用 V₁ 类 AVP 受体的特异性阻滞剂来介导，如（d(CH₂)₅¹，Tyr(Me)²，Arg⁸）-Vasopressin 和（d(CH₂)₅¹，Tyr(Me)²，Thr⁴，Orn⁸，des-Gly-NH₂⁹）-Vasotocin 分别为 V₁ 和 OT 受体的特异性阻滞剂。在培养的 DRG 细胞中，V(1a)受体 mRNA 可持续表达，而 V(1b)受体 mRNA 则在培养过程中持续表达。这些结果表明，AVP 通过激活 V(1a)受体调节 DRG 胶质细胞的活性。
