Effect of Anatoxin-a(s) from Anabaena flos-aquae NRC-525-17 on Blood Pressure, Heart Rate, Respiratory Rate, Tidal Volume, Minute Volume, and Phrenic Nerve Activity in Rats. (Reannouncement with New Availability Information).

摘要

The effects of anatoxin from the cyanobacterium Anabaena flos-aquae 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 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.