title: Correlation of five radioimmunoassay systems for measurement of bovine plasma pregnancy-associated glycoprotein concentrations at early pregnancy period.
abstract: The measurement of serum or plasma PAG concentrations is currently used as a specific method for pregnancy diagnosis in cattle. In this study, the correlation between five radioimmunoassay systems (RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool) developed for measurement of PAG concentrations in ruminant species was investigated in plasma from pregnant Friesian Holstein females. Plasma PAG concentrations (ng/mL) measured by different RIA systems were significantly correlated between them ( > or = 0.81; P<0.001). PAG concentrations increased significantly from Day 21 (n=27) to 30 (n=37) after AI by use of all PAG-RIA systems. From Day 30 to 80 after AI, lower PAG concentrations were observed when using the homologous system RIA-497. The addition of several proteinase inhibitors changed neither the non specific binding nor the B(0) binding to the tracer. Our results suggest that all tested PAG-RIA (RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool) are highly correlated and can be useful to follow PAG concentrations in samples collected during the first trimester of gestation.
authors.affiliation: Laboratory of Endocrinology and Animal Reproduction, Faculty of Veterinary Medicine, University of Liege, B-4000 Liege, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Ayad
authors.forename: N M
authors.initials: NM
authors.lastname: Sousa
authors.forename: J
authors.initials: J
authors.lastname: Sulon
authors.forename: J L
authors.initials: JL
authors.lastname: Hornick
authors.forename: M
authors.initials: M
authors.lastname: Iguer-Ouada
authors.forename: J F
authors.initials: JF
authors.lastname: Beckers
mesh_terms: D000818:Animals; D002417:Cattle / Q000097:blood; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D010298:Parity; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000097:blood*; D011261:Pregnancy Trimester, First / Q000502:physiology; D011270:Pregnancy, Animal; D011863:Radioimmunoassay / Q000379:methods / Q000662:veterinary*; D012756:Sheep / Q000097:blood
chemical_list: D006023:Glycoproteins; D011257:Pregnancy Proteins