Cook W O, Iwamoto G A, Schaeffer D J, Beasley V R
Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois, Urbana 61801.
J Environ Pathol Toxicol Oncol. 1989 Dec;9(5-6):393-400.
The effects of anatoxin-a(s) [antx-a(s)] from the cyanobacterium Anabaena flos-aquae NRC-525-17 on mean arterial blood pressure, heart rate, respiratory rate, tidal volume, minute volume, and phrenic nerve activity were evaluated in anesthetized Sprague-Dawley rats. Anatoxin-a(s) was administered by continuous intravenous infusion. The initial effect of the toxin was to slow the heart rate and reduce arterial blood pressure, followed by much more pronounced reductions in these parameters. The marked decline in heart rate and blood pressure frequently occurred before there was a large decrease in respiratory minute volume [reduced by only 15.4 +/- 3% (mean +/- S.E.) compared to the predose period], suggesting that antx-a(s) has an important muscarinic action on the cardiovascular system in vivo. Phrenic nerve amplitude increased, but, nevertheless, tidal and minute volumes decreased progressively, indicating that antx-a(s), unlike most low-molecular-weight organophosphorus cholinesterase inhibitors, does not have any remarkable inhibitory action on central mediation of respiration.
在麻醉的Sprague-Dawley大鼠中，评估了来自水华鱼腥藻NRC-525-17的类毒素-a(s) [anatoxin-a(s)，简称antx-a(s)] 对平均动脉血压、心率、呼吸频率、潮气量、分钟通气量和膈神经活动的影响。通过持续静脉输注给予antx-a(s)。毒素的初始作用是使心率减慢和动脉血压降低，随后这些参数出现更显著的下降。心率和血压的显著下降常常在呼吸分钟通气量大幅降低之前出现 [与给药前相比仅降低了15.4±3%（平均值±标准误）]，这表明antx-a(s) 在体内对心血管系统具有重要的毒蕈碱样作用。膈神经振幅增加，但潮气量和分钟通气量仍逐渐下降，这表明与大多数低分子量有机磷胆碱酯酶抑制剂不同，antx-a(s) 对呼吸的中枢调节没有任何显著的抑制作用。
