Increase of the Delayed Neurotoxicity of the Organophosphorus Pesticide “Phosvel” in Starved Hens / 日本農村医学会雑誌

ABSTRACT

Phosvel is an organophosphorus pesticide known to produce delayed neurotoxicity. In our earlier investigation, the neurotoxicity was greater in hens which fasted for two weeks than in those which were normally or force fed for some weeks. This suggested a relationship between the sensitivity to the neurotoxicity of phosvel and the amount of adipose tissue of animals receiving this compound.<BR>In this study, neurotoxicity levels in five groups of hens, each fasted for different duration (3, 6, 9, 12 and 15 days) before administration of phosvel, were compared with normally fed hens. The results are as follows;<BR>1. A single oral dose of phosvel was administered to each hen at the rate of 250 mg/kg body weight.<BR>2. There were no abnormal hens in the fed group or the ‘3 days fasting’ group.<BR>3. In the ‘6 days fasting’ group, 2 out of 5 hens showed ataxia and one of them developed mild paralysis. But no hens died in this group.<BR>4. However, in both groups of ‘9’ and ‘15 days fasting’, all hens were attacked by delayed neurotoxic effect. Three out of five in each group died after developing severe paralysis.<BR>5. One bird in the ‘12 days fasting’ group died due to the acute poisoning of phosvel on day 3 after administration. This was a very rare case in the series of studies of the compound. Three out of 4 remaining hens developed severe paralysis and one of these affected hens died.<BR>6. In general, the longer the animals fasted the greater was the delayed neurotoxic effect, however, if the adipose tissue of the animals was cosumed more than a certain level by enforced fasting, the neurotoxicity tended to be markedly increased.