title: Validation of a serum immunoassay to measure progesterone and diagnose pregnancy in the West Indian manatee (Trichechus manatus).
abstract: The objective was to validate a high-sensitivity chemiluminescent assay of serum progesterone concentrations for pregnancy diagnosis in manatees. Assay analytical sensitivity was 0.1 ng/mL, with mean intra- and inter-assay coefficients of variation of 9.7 and 9.2%, respectively, and accuracy had a mean adjusted R(2) of 0.98. Methods comparison (relative to Siemen's Coat-A-Count RIA) demonstrated r=0.98, Deming regression slope of 0.95, and an intercept of 0.01. Based on ROC analysis, a progesterone concentration >or=0.4 ng/mL was indicative of pregnancy. Assay results were not significantly altered by two freeze-thaw cycles of samples. Characteristic progesterone concentrations during pregnancy were Months 1-4 (1.7-4.7 ng/mL), 5-8 ( approximately 1.0 ng/mL), and 10 and 11 (0.3-0.5 ng/mL), whereas two late-pregnant females with impending abortion had progesterone concentrations of 0.1 ng/mL. Among pregnant females, maximum progesterone concentrations occurred in autumn (3.9+/-1.8 ng/mL), and were greater during all seasons than concentrations in non-pregnant females (0.1-0.2 ng/mL). Progesterone concentrations were also significantly higher in pregnant females than in non-pregnant females and males. This highly sensitive, specific, and diagnostic assay will be valuable for monitoring pregnancy and abortion in manatees.
authors.affiliation: University of Florida College of Veterinary Medicine, Aquatic Animal Health Program, 2015 SW 16th Avenue, P.O. Box 100126, Gainesville, FL 32610-0126, USA. ktripp@savethemanatee.org
authors.forename: K M
authors.initials: KM
authors.lastname: Tripp
authors.forename: J P
authors.initials: JP
authors.lastname: Verstegen
authors.forename: C J
authors.initials: CJ
authors.lastname: Deutsch
authors.forename: R K
authors.initials: RK
authors.lastname: Bonde
authors.forename: M
authors.initials: M
authors.lastname: Rodriguez
authors.forename: B
authors.initials: B
authors.lastname: Morales
authors.forename: D L
authors.initials: DL
authors.lastname: Schmitt
authors.forename: K E
authors.initials: KE
authors.lastname: Harr