The toxicity of cyanobacterial toxins in the mouse: II Anatoxin-a

• Published in: Human & experimental toxicology 1999-03, Vol.18 (3), p.168-173
• Main Authors: Fawell, J K, Mitchell, R E, Hill, R E, Everett, D J
• Format: Article
• Language: English
• Subjects: Abnormalities, Drug-Induced - etiology; Animals; Bacterial Toxins - chemistry; Bacterial Toxins - toxicity; Bacteriology; Behavior, Animal - drug effects; Behavior, Animal - physiology; Biological and medical sciences; Central Nervous System - drug effects; Chickens; Drug Evaluation, Preclinical; Female; Fundamental and applied biological sciences. Psychology; Guinea Pigs; Ileum - drug effects; In Vitro Techniques; Male; Marine Toxins - chemistry; Marine Toxins - toxicity; Mice; Microbiology; Microcystins; Muscle Contraction - drug effects; Neck Muscles - drug effects; Neck Muscles - physiology; Nicotine - pharmacology; No-Observed-Adverse-Effect Level; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Phrenic Nerve - drug effects; Pregnancy; Psychomotor Performance - drug effects; Psychomotor Performance - physiology; Rats; Toxicity Tests; Tropanes
• ISSN: 0960-3271; 1477-0903
• DOI: 10.1177/096032719901800306

Blooms of cyanobacteria are known to have caused poisoning in fish, waterfowl, animals and man. One of the low molecular weight toxins responsible for this is the neurotoxin anatoxin-a which has been detected in reservoirs used for domestic water supplies. While the acute behaviour of this alkaloid is clear, there is uncertainty regarding the effects on man of ingestion of anatoxin-a at low levels over longer periods. In order to assess this risk, a series of in vitro and in vivo experiments were undertaken to investigate the pharmacology, sub-acute toxicity, and the teratogenicity of anatoxin-a in the mouse. The results of this work were as follows: (1) Pharmacological screening studies confirmed that anatoxin-a is a potent nicotinic agonist which can produce neuromuscular blockade and death by respiratory arrest. Recovery from a single sub-lethal dose is rapid and complete; (2) Repeated sub-lethal oral administration over 28 days in the mouse did not produce any reliable evidence of treatment-related toxicity; (3) From a preliminary screening study anatoxin-a does not appear to be a developmental toxicant in the mouse. These results indicate that a guideline value for anatoxin-a in drinking water of 1 μg l-1 would provide an adequate margin of safety.