title: Concentration of phenylbutazone (PBZ) and 13, 14-dihydro-15 keto PGF(2alpha) (PGFM) in blood and seminal plasma of stallions treated with PBZ.
abstract: Three stallions, 3 to 5 yr old and approximately 550 kg bodyweight, were used in a switchback experimental design to study the effect of daily, oral administration of 3g PBZ on the concentrations of PBZ and PGFM in blood (plasma) and seminal plasma (SP). Control and treatment periods were each 24 days' duration. Blood and semen samples were simultaneously collected every three days during these periods. Each stallion served consecutively as a control, treated, control, and treated subject for 24 days in each of the four periods. Concentrations of PBZ were obtained using HPLC and PGFM by specific RIA. Concentrations (mean +/- SE) of PBZ averaged 9.2 +/- 0.12 ug/ml in plasma but were undetectable in SP following the treatments. There was no significant difference in the plasma levels of PGFM between pre- and post- treatment values. However, there was a significant difference (P<0.001) in PGFM concentrations of seminal plasma before and after treatment. Results of this study suggest that daily, oral adminisration of 3g PBZ for 24 days to mature stallions can significantly decrease seminal plasma concentrations of PGFM. The physiological significance of this observation remains speculative.
authors.affiliation: Department of Reproduction, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610 USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Larsen
authors.forename: L F
authors.initials: LF
authors.lastname: Archbald
authors.forename: C L
authors.initials: CL
authors.lastname: Chen
authors.forename: R R
authors.initials: RR
authors.lastname: Gronwall
authors.forename: J L
authors.initials: JL
authors.lastname: Collier
authors.forename: A C
authors.initials: AC
authors.lastname: Asbury
authors.forename: W W
authors.initials: WW
authors.lastname: Thatcher