Immunolocalization of Leptin and its Receptor (ObR-b) in Equine Placenta at Term and Plasma Level Measurement in the Late Gestation

• Published in: Journal of equine veterinary science Vol. 78; pp. 1 - 5
• Main Authors: Pazinato, Fernanda Maria, Curcio, Bruna da Rosa, Varela Junior, Antonio Sergio, Corcini, Carine Dahl, Wendt, Camila Gervini, Moreira, Fabiana, Schmit, Rubia Alves, Nogueira, Carlos Eduardo Wayne
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-07-2019
• Subjects: Autocrine action; Immunofluorescence; Mares; Placental metabolism; Placental metabolism; Autocrine action; Immunofluorescence; Mares
• ISSN: 0737-0806; 1542-7412
• DOI: 10.1016/j.jevs.2019.03.008

Placental tissues from humans, rodents, and farm animal contain leptin and its receptor. Expression of leptin has already been described in horses, although there is no description about immunolocalization of leptin and its receptor. The aim of the present study was to investigate the presence and distribution of leptin and ObR-b in the equine placenta at term by immunofluorescence staining, and the changes on plasma leptin concentrations during late gestation. The present study involved eight Criollo-type mares carrying healthy pregnancies. Blood samples were collected during the third trimester of gestation, at foaling, and at 24 hours after foaling. Leptin concentrations were analyzed via radioimmunoassay. Plasma leptin concentrations did not change from the 8th to the 10th month of gestation and displayed a discrete decrease 24 hours after parturition (P = .07). The expression of leptin and ObR-b was observed in the cytoplasm of pseudostratified epithelial cells in the areolar region and in the epithelium of microcotyledons. Also, leptin receptor was allocated in the apical surface of the cells. The presence of leptin and its receptor (ObR-b) in the placenta of mares at term supports an endocrine and autocrine/paracrine action of leptin within this organ.
•Leptin and its receptor are present in equine placenta at term.•Leptin and its receptor promote an intrinsic endocrine regulation in placenta.•Plasma leptin level remained constant from eighth month of gestation until foaling.