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Neurotoxicity by the dividing administration of critical dose of phosvel.

Kinebuchi H; Konno N
Proceedings of the VII International Congress of Rural Medicine, September 17-21, Salt Lake City, Utah. International Association of Agricultural Medicine, 1978 Sep; :285-287
The effect of dose division on the neurotoxicity of phosvel (21609905) (leptophos) was studied in hens. White-Leghorn-hens were given 250 milligrams per kilogram (mg/kg) leptophos orally in a single dose or the equivalent as 50, 83, or 125mg/kg daily for up to 5 days. In a second experiment, hens were given 25mg/kg leptophos daily for 10 days, 10mg/kg daily for 25 days, 7.5mg/kg daily for 33 days, or 5mg/kg daily for 50 days. In a third experiment, hens were given a total of 250mg/kg leptophos either as a 50mg/kg dose once a day for 5 days or fractionated into five doses given daily every other day or every third, fourth, or fifth day. The birds were observed for clinical signs of toxicity. Hens given single 125 or 250mg/kg doses of leptophos showed transient lethargy and loss of appetite. Ataxia developed 8 to 14 days after treatment in hens given 50 or 83mg/kg leptophos for 5 days. Three of five hens given 25mg/kg leptophos daily for 10 days and four of five given 10mg/kg daily for 25 days developed ataxia. One of five hens given 7.5mg/kg for 33 days or 5mg/kg for 50 days developed ataxia or paralysis. Most hens given five fractionated doses of 250mg/kg leptophos every third, fourth, and fifth days developed ataxia. Four of five hens given five fractionated doses every third day progressed to paralysis. One of five birds in the other five fractional dose groups also progressed to paralysis. The authors conclude that dividing the doses of leptophos increases its neurotoxicity. This may reflect more efficient absorption of divided small doses than a single large dose.
NIOSH-Grant; Grants-other; In-vivo-studies; Animal-studies; Organo-phosphorus-compounds; Pesticides; Neurotoxic-effects; Clinical-symptoms; Laboratory-techniques; Dose-response
Prev Med & Environmental Hlth University of Iowa Inst/agric Med & Environ Hlth Iowa Oakdale, Iowa 52319
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Conference/Symposia Proceedings
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Other Occupational Concerns; Grants-other
Source Name
Proceedings of the VII International Congress of Rural Medicine, September 17-21, Salt Lake City, Utah
Performing Organization
University of Iowa, Iowa City, Iowa
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division