Wang Hui, Huai Ruituo, Yang Junqing, Li Yanchun
Shandong Provincial Key Laboratory of Robotics and Intelligent Technology, Shandong University of Science and Technology, 579 Qianwangang Road, Qingdao, Shandong, P.R. China.
Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America.
PLoS One. 2016 Oct 31;11(10):e0165895. doi: 10.1371/journal.pone.0165895. eCollection 2016.
Protein tyrosine kinase (PTK) mediated the tyrosine phosphorylation modification of neuronal receptors and ion channels. Whether such modification resulted in changes of physiological functions was not sufficiently studied. In this study we examined whether the hypoxic respiratory response-which is the enhancement of breathing in hypoxic environment could be affected by the inhibition of PTK at brainstem ventral respiratory neuron column (VRC). Experiments were performed on urethane anesthetized adult rabbits. Phrenic nerve discharge was recorded as the central respiratory motor output. Hypoxic respiratory response was produced by ventilating the rabbit with 10% O2-balance 90% N2 for 5 minutes. The responses of phrenic nerve discharge to hypoxia were observed before and after microinjecting PTK inhibitor genistein, AMPA receptor antagonist CNQX, or inactive PTK inhibitor analogue daidzein at the region of ambiguus nucleus (NA) at levels 0-2 mm rostral to obex where the inspiratory subgroup of VRC were recorded. Results were as follows: 1. the hypoxic respiratory response was significantly attenuated after microinjection of genistein and/or CNQX, and no additive effect (i.e., further attenuation of hypoxic respiratory response) was observed when genistein and CNQX were microinjected one after another at the same injection site. Microinjection of daidzein had no effect on hypoxic respiratory response. 2. Fluorescent immunostaining showed that hypoxia significantly increased the number of phosphotyrosine immunopositive neurons in areas surrounding NA and most of these neurons were also immunopositive to glutamate AMPA receptor subunit GluR1. These results suggested that PTK played an important role in regulating the hypoxic respiratory response, possibly through the tyrosine phosphorylation modification of glutamate AMPA receptors on the respiratory neurons of ventral respiratory neuron column.
蛋白酪氨酸激酶（PTK）介导神经元受体和离子通道的酪氨酸磷酸化修饰。这种修饰是否导致生理功能的变化尚未得到充分研究。在本研究中，我们研究了在脑干腹侧呼吸神经元柱（VRC）处抑制PTK是否会影响低氧呼吸反应，即在低氧环境中呼吸增强的现象。实验在氨基甲酸乙酯麻醉的成年兔身上进行。记录膈神经放电作为中枢呼吸运动输出。通过用10% O₂ - 90% N₂混合气体对兔子通气5分钟来产生低氧呼吸反应。在记录VRC吸气亚组的闩前0 - 2毫米水平的疑核（NA）区域微注射PTK抑制剂染料木黄酮、AMPA受体拮抗剂CNQX或无活性的PTK抑制剂类似物大豆苷元之前和之后，观察膈神经放电对低氧的反应。结果如下：1. 微注射染料木黄酮和/或CNQX后，低氧呼吸反应显著减弱，当在同一注射部位先后微注射染料木黄酮和CNQX时，未观察到叠加效应（即低氧呼吸反应进一步减弱）。微注射大豆苷元对低氧呼吸反应无影响。2. 荧光免疫染色显示，低氧显著增加了NA周围区域磷酸酪氨酸免疫阳性神经元的数量，并且这些神经元中的大多数对谷氨酸AMPA受体亚基GluR1也呈免疫阳性。这些结果表明，PTK在调节低氧呼吸反应中起重要作用，可能是通过对腹侧呼吸神经元柱呼吸神经元上的谷氨酸AMPA受体进行酪氨酸磷酸化修饰来实现的。
