Fate of avermectin B sub 1a in rats

Journal Article · Wed Feb 28 23:00:00 EST 1990 · Journal of Agricultural and Food Chemistry; (USA)

DOI:https://doi.org/10.1021/jf00093a058· OSTI ID:6524610

Maynard, M S; Halley, B A; Green-Erwin, M; Alvaro, R; Gruber, V F; Hwang, Shuchen; Bennett, B W; Wislocki, P G ^[1]

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1. Merck, Sharp and Dohme Research Labs., Three Bridges, NJ (USA)

Male and female rats were administered ({sup 3}H)avermectin B{sub 1a} or a mixture of ({sup 3}H)- and ({sup 14}C)avermectin B{sub 1a} as a single oral dosage at 1.4 or 0.14 mg/kg. Most of the dose (69-82%) was recovered in the feces, with 1% or less found in the urine. The total residue levels in liver, kidney, muscle, and fat tissues were <5.3 ppm at 1 day after dosing and essentially depleted within 7 days after dosing. For all tissues analyzed, the depletion half-life of the total radioactive residue was approximately 1.2 days, while the half-life of avermectin B{sub 1a} was between 0.6 and 1.0 day. The tissue residue was shown to be qualitatively similar between the tissue type, dose, sex, pretreatment with or without unlabeled avermectin B{sub 1a}, and label ({sup 3}H or {sup 14}C). A major metabolite (3{double prime}-desmethyl) and a minor metabolite (24-hydroxymethyl) isolated and identified from rat liver microsomal incubations of avermectin B{sub 1a} were identified in the rat tissues. These two metabolites and avermectin B{sub 1a} accounted for > 85% of the tissue residue. The fate of ({sup 3}H)avermectin B{sub 1a} was the same as the fate of ({sup 14}C)avermectin B{sub 1a}, demonstrating the stability of the {sup 3}H label on avermectin B{sub 1a} and the validity of its use in animal metabolism studies.

• OSTI ID: 6524610
• Journal Information: Journal of Agricultural and Food Chemistry; (USA), Journal Name: Journal of Agricultural and Food Chemistry; (USA) Vol. 38:3; ISSN JAFCA; ISSN 0021-8561
• Country of Publication: United States
• Language: English

Related Subjects

553003* -- Agriculture &amp; Food Technology-- Pest &amp; Disease Control-- (1987-)
60 APPLIED LIFE SCIENCES
ANIMALS
BODY
CARBON 14 COMPOUNDS
CLEARANCE
DIGESTIVE SYSTEM
EXCRETION
GLANDS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIVER
MAMMALS
METABOLISM
METABOLITES
ORAL ADMINISTRATION
ORGANS
PESTICIDES
RATS
RODENTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES