Fang Fang, Jiao Yong-gang, Li Guo-cai, Wu Zhong-hai
Department of Physiology, Southern Medical University, Guangdong, Guangzhou 510515, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2009 Dec;29(12):2410-3.
To explore the role of glial cell metabolism in the generation and regulation of central respiratory rhythm.
The medulla oblongata slices (600-700 microm) containing the medial region of the nucleus retrofacialis (mNRF) with the hypoglossal nerve rootlets retained from 12 neonatal (0-3 days) Sprague-Dawley rats were prepared and perfused with modified Kreb's solution (MKS). Upon recording of respiratory rhythmical discharge activity (RRDA) of the rootlets of the hypoglossal nerve, the brain slices were treated with glial cell metabolism antagonist L-methionine sulfoximine (L-MSO, 50 micromol/L) for 20 min followed by application of glial cell metabolism agonist L-glutamine (L-GLN, 30 micromol/L) for 20 min, or with L-MSO for 20 min with additional L-GLN for 20 min. The changes in the RRDA of the rootlets of the hypoglossal nerve in response to the treatments were recorded.
L-MSO prolonged the respiratory cycle (RC) and expiratory time (TE), and reduced the integral amplitude (IA) and the inspiratory time (TI) in the brain slices. L-GLN induced a significant decrease in RC and TE, but IA and TI showed no obvious variations. The effect of L-MSO on the respiratory rhythm was reversed by the application of L-GLN.
Glial cell metabolism may play an important role in the modulation of RRDA in neonatal rat brainstem.
探讨胶质细胞代谢在中枢呼吸节律产生与调节中的作用。
从12只新生（0 - 3天）的Sprague-Dawley大鼠制备含面神经后核内侧区域（mNRF）并保留舌下神经根的延髓切片（600 - 700微米），用改良的克雷布斯溶液（MKS）灌注。在记录舌下神经根的呼吸节律性放电活动（RRDA）后，将脑片用胶质细胞代谢拮抗剂L-蛋氨酸亚砜胺（L-MSO，50微摩尔/升）处理20分钟，然后应用胶质细胞代谢激动剂L-谷氨酰胺（L-GLN，30微摩尔/升）20分钟，或用L-MSO处理20分钟并额外给予L-GLN 20分钟。记录舌下神经根RRDA对这些处理的变化。
L-MSO延长了脑片中的呼吸周期（RC）和呼气时间（TE），并降低了积分幅度（IA）和吸气时间（TI）。L-GLN使RC和TE显著降低，但IA和TI无明显变化。应用L-GLN可逆转L-MSO对呼吸节律的影响。
胶质细胞代谢可能在新生大鼠脑干RRDA的调节中起重要作用。
