生理学报
生理學報
생이학보
ACTA PHYSIOLOGICA SINICA
2005年
1期
91-96
,共6页
腺苷A1受体%面神经后核内侧区%呼吸节律%吸气神经元%放电频率
腺苷A1受體%麵神經後覈內側區%呼吸節律%吸氣神經元%放電頻率
선감A1수체%면신경후핵내측구%호흡절률%흡기신경원%방전빈솔
adenosine A1 receptors%the medial region of the nucleus retrofacialis%rhythmical respiration%inspiration-related neurons%discharge frequency
实验旨在探讨腺苷A1受体在对基本呼吸节律调制中的可能作用.制作新生大鼠离体延髓脑片标本,主要包含面神经后核内侧区(themedial regionofthenucleus retrofacialis,mNRF),并保留完整的舌下神经根.以改良Kreb's液灌流脑片,记录mNRF吸气神经元的电活动,并同步记录舌下神经根呼吸节律性放电(respiratory rhythmical discharge activity,RRDA).在灌流液中先分别单独给予腺苷A1受体的特异性拮抗剂8-环戊-1,3-二丙基黄嘌呤(8-cyclopentyl-1,3-dipropylxanthine,DPCPX)和特异性激动剂R-苯异丙基-腺苷(R-phenylisopropyl-adenosine,R-PIA);再分别先后给予R-PIA和R-PIA+DPCPX,观察RRDA和吸气神经元电活动的变化.结果显示,给予腺苷A1受体拮抗剂DPCPX后,呼气时程和呼吸周期明显缩短,吸气神经元中期放电的频率和峰频率显著增大;给予腺苷A1受体激动剂R-PIA后,吸气时程、积分幅度和吸气神经元中期放电的频率和峰频率均显著降低,呼吸周期明显延长,且R-PIA的呼吸抑制作用可部分地被DPCPX逆转.实验结果提示,腺苷A1受体可能通过介导吸气神经元的抑制性突触输入参与节律性呼吸的调制.
實驗旨在探討腺苷A1受體在對基本呼吸節律調製中的可能作用.製作新生大鼠離體延髓腦片標本,主要包含麵神經後覈內側區(themedial regionofthenucleus retrofacialis,mNRF),併保留完整的舌下神經根.以改良Kreb's液灌流腦片,記錄mNRF吸氣神經元的電活動,併同步記錄舌下神經根呼吸節律性放電(respiratory rhythmical discharge activity,RRDA).在灌流液中先分彆單獨給予腺苷A1受體的特異性拮抗劑8-環戊-1,3-二丙基黃嘌呤(8-cyclopentyl-1,3-dipropylxanthine,DPCPX)和特異性激動劑R-苯異丙基-腺苷(R-phenylisopropyl-adenosine,R-PIA);再分彆先後給予R-PIA和R-PIA+DPCPX,觀察RRDA和吸氣神經元電活動的變化.結果顯示,給予腺苷A1受體拮抗劑DPCPX後,呼氣時程和呼吸週期明顯縮短,吸氣神經元中期放電的頻率和峰頻率顯著增大;給予腺苷A1受體激動劑R-PIA後,吸氣時程、積分幅度和吸氣神經元中期放電的頻率和峰頻率均顯著降低,呼吸週期明顯延長,且R-PIA的呼吸抑製作用可部分地被DPCPX逆轉.實驗結果提示,腺苷A1受體可能通過介導吸氣神經元的抑製性突觸輸入參與節律性呼吸的調製.
실험지재탐토선감A1수체재대기본호흡절률조제중적가능작용.제작신생대서리체연수뇌편표본,주요포함면신경후핵내측구(themedial regionofthenucleus retrofacialis,mNRF),병보류완정적설하신경근.이개량Kreb's액관류뇌편,기록mNRF흡기신경원적전활동,병동보기록설하신경근호흡절률성방전(respiratory rhythmical discharge activity,RRDA).재관류액중선분별단독급여선감A1수체적특이성길항제8-배무-1,3-이병기황표령(8-cyclopentyl-1,3-dipropylxanthine,DPCPX)화특이성격동제R-분이병기-선감(R-phenylisopropyl-adenosine,R-PIA);재분별선후급여R-PIA화R-PIA+DPCPX,관찰RRDA화흡기신경원전활동적변화.결과현시,급여선감A1수체길항제DPCPX후,호기시정화호흡주기명현축단,흡기신경원중기방전적빈솔화봉빈솔현저증대;급여선감A1수체격동제R-PIA후,흡기시정、적분폭도화흡기신경원중기방전적빈솔화봉빈솔균현저강저,호흡주기명현연장,차R-PIA적호흡억제작용가부분지피DPCPX역전.실험결과제시,선감A1수체가능통과개도흡기신경원적억제성돌촉수입삼여절률성호흡적조제.
This study was designed to investigate whether adenosine A1 receptors could modulate primary rhythmical respiration in mammals. Experiments were performed in in vitro brainstem slice preparations from neonatal rats. These preparations included the medial region of the nucleus retrofacialis (mNRF) with the hypoglossal nerve rootlets retained. The activity of the inspiration-related neurons (I neurons) in mNRF and respiratory rhythmical discharge activity (RRDA) of the hypoglossal nerve rootlets were simultaneously recorded by using microelectrodes and suction electrodes, respectively. Possible roles of adenosine A 1 receptors in rhythmical respiration were investigated by administration of adenosine A1 receptor agonist R-phenylisopropyl-adenosine (R-PIA) and its specific antagonist 8-cyclopentyl-1,3- dipropylxanthine (DPCPX) into a modified Kreb's perfusion solution (MKS). DPCPX induced a significant decrease in the expiratory time and the respiratory cycles, and an increase in the discharge frequency and peak frequency of I neurons in the middle phase of inspiration. However, R-PIA significantly decreased the inspiratory time and integral amplitude as well as prolonged respiratory cycle. Moreover, the discharge frequency and the peak frequency of I neurons were decreased in the middle phase of inspiration, but not in the initial and terminal phases. The effect of R-PIA on rhythmical discharges could be partially reversed by additional application of DPCPX. These results indicate that adenosine A1-receptors are possibly involved in the modulation of rhythmical respiration through the inhibitory synaptic input from I neurons.
