EFFECTS OF ACETALDEHYDE ON THE AUTOMATICITY OF THE GUINEA-PIG SINUS NODE
EFFECTS OF ACETALDEHYDE ON THE AUTOMATICITY OF THE GUINEA-PIG SINUS NODE
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DOI：
10.1016/0741-8329(89)90033-5
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发表时间：
1989-03-01
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
本研究的目的是表征乙醛 (ACA) 对窦房结自动性 (SNA) 的影响。使用在37℃下灌注了Tyrode溶液的豚鼠窦房制剂。细胞内微电极用于监测信噪比（SNR）。乙醛3倍10-5M对SNR没有影响，而3×。 10-3 M 具有正变时作用。 SNR 的增加与辅助起搏纤维的慢舒张去极化 (SDD) 斜率的增加相关，而最大舒张电位 (MDP) 没有变化。乙醛3倍10-2 M发挥双相效应：SNR先增强后降低。普萘洛尔阻断了这种变时作用的积极成分。阴性成分未被普萘洛尔、酚妥拉明或阿托品修饰。结论是ACA对豚鼠窦房结具有正向和负向变时作用。这种双相效应的积极成分是通过 β-肾上腺素能机制介导的，并且与 SDD 的增加有关。负面成分不是由α-或β-肾上腺素或毒蕈碱刺激引起的。
The objective of this investigation was to characterize the effects of acetaldehyde (ACA) on sinus node automaticity (SNA). Guinea pig sinoatrial preparations superfused with Tyrode''s solution at 37.degree.C were used. Intracellular microelectrodes were used to monitor SN rate (SNR). Acetaldehyde 3 .times. 10-5 M had no effect on SNR, while 3 .times. 10-3 M had a positive chronotropic action. The increase in SNR was associated with an increase in the slope of the slow diastolic depolarization (SDD) of subsidiary pacemaker fibers, with no change in the maximum diastolic potential (MDP). Acetaldehyde 3 .times. 10-2 M exerted a biphasic effect: the SNR was enhanced and then depressed. Propranolol blocked the positive component of this chronotropic action. The negative component was not modified by propranolol, phentolamine, or atropine. It is concluded that ACA exerts both positive and negative chronotropic actions on the guinea pig sinus node. The positive component of this biphasic effect is mediated through a beta-adrenergic mechanism and it is associated with an increase in the SDD. The negative component is not due to alpha- or beta-adrenergic or muscarinic stimulation.