EFFECTS OF ACETALDEHYDE ON MEMBRANE-POTENTIALS OF SINUS NODE PACEMAKER FIBERS
EFFECTS OF ACETALDEHYDE ON MEMBRANE-POTENTIALS OF SINUS NODE PACEMAKER FIBERS
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DOI：
10.1016/0741-8329(90)90057-j
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发表时间：
1990-01-01
期刊：
影响因子：
2.3
通讯作者：
CARPENTIER, RG
中科院分区：
文献类型：
--
作者：
BROWN, RA;CARPENTIER, RG
本文报道的实验是为了描述乙醛在肾上腺素能和胆碱能阻断缺失和存在的情况下对窦房结辅助起搏器纤维膜电位（MP）的影响。将豚鼠窦房制剂与Tyrode溶液在37℃下灌注，并以5 Hz电刺激。用细胞内微电极记录窦房结辅助起搏器纤维的MP。乙醛3倍。10-6米和3倍。10-3 M对最大舒张电位（MDP）无影响，3 -3 M对最大舒张电位（MDP）无影响。10-5米和3倍。10- 2m对MDP施加了去极化效果，而不影响超调（OS）。MDP的下降与动作电位（AAP）振幅和第0相最大速度（Vmax O）的降低有关。乙醛对MDP的抑制作用不被肾上腺素受体阻滞剂或阿托品所消除。乙醛浓度在3倍。10-5和3倍。10 ~ 2 M延长动作电位持续时间（APD）。乙醛3倍。即使在阿托品或心得安存在的情况下，10-3 M也不影响MDP。肾上腺素能阻滞剂不能消除乙醛的apd延长作用。综上所述，乙醛对MDP和APD的作用不依赖于肾上腺素能和胆碱能机制。
The experiments reported here were performed to characterize the effects of acetaldehyde on membrane potentials (MP) of sinus node subsidiary pacemaker fibers in the absence and presence of adrenergic and cholinergic blockade. Guinea pig sinoatrial preparations were superfused with Tyrode''s solution at 37.degree.C while electrically stimulated at 5 Hz. Intracellular microelectrodes were used to record the MP of sinus node subsidiary pacemaker fibers. Acetaldehyde 3 .times. 10-6 M and 3 .times. 10-3 M had no effect on maximum diastolic potential (MDP), while 3 .times. 10-5 M and 3 .times. 10-2 M exerted a depolarizing effect on the MDP, without affecting the overshoot (OS). The fall in MDP was associated with a reduction in the amplitude of the action potential (AAP) and the maximum velocity of phase 0 (Vmax O). The depressant effect of acetaldehyde on MDP was not abolished by adrenergic blockers or atropine. Concentrations of acetaldehyde between 3 .times. 10-5 and 3 .times. 10-2 M prolonged the action potential duration (APD). Acetaldehyde 3 .times. 10-3 M did not affect MDP even in the presence of atropine or propranolol. The APD-prolonging effect of acetaldehyde was not abolished by adrenergic blockers. In summary, the actions of acetaldehyde on MDP and APD were independent of adrenergic and cholinergic mechanisms.