title: Monthly variations in the pharmacokinetics of antipyrine in the rat: circannual rhythm or random variation?
abstract: We examined the pharmacokinetics of antipyrine in the rat over an 18 month period to determine whether or not the variations in pharmacokinetic parameters previously reported exhibited a circannual rhythm. While the clearance of antipyrine varied over the study period, no discernible rhythmic pattern was found. Comparing this data with previously published work also failed to demonstrate a rhythmic pattern of variability. Unlike previous investigations, we found only relatively small variations in antipyrine volume of distribution and half-life from month to month. These data indicate that the monthly variability in the pharmacokinetics of antipyrine in the rat are random and do not exhibit a circannual rhythm.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy & Allied Health Professions, Wayne State University, Detroit, Michigan 48202.
authors.forename: C K
authors.initials: CK
authors.lastname: Svensson
authors.forename: M T
authors.initials: MT
authors.lastname: Chong
authors.forename: D J
authors.initials: DJ
authors.lastname: Edwards
mesh_terms: D000818:Animals; D000983:Antipyrine / Q000493:pharmacokinetics*; D008297:Male; D008657:Metabolic Clearance Rate; D010507:Periodicity; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000983:Antipyrine