title: Progesterone production in mares and echographic evaluation of the corpora lutea formed after follicular aspiration.
abstract: Ultrasound-guided follicular aspiration was performed in 26 Criollo crossbred mares, followed by the evaluation of ultrasonographic images of the Corpus luteum (CL) that was formed after puncture of follicles of different diameters (Group 25-29 mm; Group 30-35 mm and Group >35 mm). Serum progesterone (P(4) ) concentrations were measured to determine CL function. The size of the CL was measured and the CL was classified based on the following echoscore: 1- anechoic tissue; 2- poorly defined luteal structure with low echogenicity; 3- echogenicity analogous to a luteal structure. The proportion of aspirated follicles that formed a functional CL (based on P(4) concentration) 8 days after aspiration was 57.1% (4/7; CL size 25-29 mm), 75.0% (6/8; CL size 30-35 mm) and 72.7% (8/11; CL size >35 mm), respectively (p > 0.05). The echographic scores of aspirated follicles (indicating the presence or absence of a CL) were consistent with serum P(4) concentrations (p < 0.0001). Of 26 aspirations, 18 resulted in luteal function confirmed by increased progesterone concentrations ([P(4) ] > 1.0 ng/ml); 17 of these mares (94.4%) had an echoscore (2-3) compatible with luteinization (p = 0.0372). Eight days after aspiration, serum [P(4) ] > 2.0 ng/ml was associated with high (p = 0.0056) CL echoscore (3) in 15 of 17 mares (88.2%). The echoscore used in this study was valuable as a screening test to detect the presence of a functional CL after aspiration. An echoscore of 3 served as a practical and efficient method to confirm luteinization.
authors: Department of Large Animal Clinics, Federal University of Santa Maria, Santa Maria, Brazil.
authors: F D
authors: FD
authors: Mozzaquatro
authors: J P
authors: JP
authors: Verstegen
authors: R H
authors: RH
authors: Douglas
authors: M H T
authors: MH
authors: Troedsson
authors: F D
authors: FD
authors: Delacorte
authors: C A M
authors: CA
authors: Silva
authors: M I B
authors: MI
authors: Rubin
mesh_terms: D000818:Animals; D003338:Corpus Luteum / Q000502:physiology*; D005260:Female; D006736:Horses / Q000502:physiology*; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism*
chemical_list: D011374:Progesterone