pH降低和尼古丁对家兔颈动脉体化学感受器活动的影响  

EFFECTS OF L0W pH AND NICOTINE ON CAROTID B0DY CHEMORECEPTOR ACTIVITY IN THE RABBIT

作　　者：庄甲举[1] 庞雷[2] 董力[2] 

机构地区：[1]解放军石家庄医学高等专科学校科研中心,石家庄050081 [2]河北省医学科学院生理研究室,石家庄050021

出　　处：《生理学报》1997年第5期589-593,共5页Acta Physiologica Sinica

基　　金：国家自然基金!39270279

摘　　要：在29只家兔的颈动脉体-窦神经标本，记录了55个窦神经中化学感受性传入单位的电活动。结果如下：（1）灌流液pH降低时，所有单位的放电均增加，频率由0．86±0．21增至1．75±040imp／s（P＜0.001）。（2）在灌洗液中加入尼古丁（1，3，6，10和15μg/ml）后，10个单位的自发放电频率，由0．60±0.21分别增加到0．96±0．21，1．19±0.30，1．24±0．29，1．48±0．41和1．82±0．39imp／s，呈明显的剂量依赖性肝（r=0．94，P＜O．001）。简箭毒可阻断尼古丁的作用，但对自发放电无显著影响。（3）当以酸性Locke氏溶液灌流标本时，19个单位的放电频率由0.95±0．34增至1.84±0．55imp／s；在酸性灌流液中加入尼古丁后，放电频率由0.96±0．25增至1．53±0．24imp／s；与单纯酸刺激时相比，放电频率增加幅度减小（P＜0．05）。（4）17个自发放电频率为1.08±0．33imp／s的单位，换以酸性Locke氏液灌流后，放电频率增加到1．64±0．43imp／s；加筒箭毒后，由对照的1.01±0.34增至1．70±0．43imp／s；灌流液pH降低时筒箭毒对化学感受性单位放电频率的变化无显著影响。上述结果提示：（1）ACh在颈动脉体化学感受性功能方面可能仅起调质的作用。The unit discharges of carotid chemosensory afferent fihers were rec0rded in the in vitro carotid body (CB ) -sinus nerve preparations (n = 55 ) from 29 ralibits. The results were as follows: (1 ) The discharge of all the units increased from 0. 86± 0. 21 to 1. 75 ± 0.40 imp/s (P < 0. 001 ) upon lowering the pH of modified Locke solution. (2)Addition of nicotine at doses of 1, 3, 6, 10 and 15 μg/ml to the solution led to a dosedependent increase in the discharge from 0.6O ± O.21 to 0.96 ± 0.21, 1.19 1 0. 30,1 .24 ± 0.29, 1.48 ± 0.41 and 1 .82 ± O.39 imp/s, respectively (r = 0.94, P <0.001 ) n =10). Nicotinic stimulati0n was antagonized by D-tub0curarine but the basal discharge was not significantly affected. (3) Superfusion of the CB with acid solution increased the discharge from O.95 ± O.34 to 1 .84 ± 0.55 imp/s (P < 0.0l, n = 19);Afer injections of nicotine 1～ 5 pg/Inl to acid perfusate the unit discharge showed an increase from 0.96 ± 0.25 to 1 .53 ± 0.24,imp/s. The degree of increase was less as compared with that due to mere acidification (P < 0. 05) - (4) D-tubocurarine did not alter the action of acid solution on chemosensory discharge (P > 0.05, n = l7). The present results suggest that ACh might act only as a modulator on carotid chemosensory activity without involving N-cholinergic receptor directly as did by low pH perfusion of CB.

关 键 词：颈动脉体 化学感受器 PH值 尼古丁 

分 类 号：R339.172[医药卫生—人体生理学]