Histomorfometria microcotiledonar da placenta de éguas com placentite ascendente induzida submetidas a diferentes tratamentos

Abstract

Fetal health is influenced by the functions of the placenta, epithelochoral, diffuse and microcotylated organ. Pathologies, such as placentitis, can lead to the detachment of the uterus-placenta union, resulting in pictures of fetal hypoxia and disturbances in hormonal production. The aim of the present study was to investigate the effects of estradiol on the microcotyledons of the placenta of mares with induced placentitis submitted to different treatments with the aid of digital image analysis. Thirty Crioulas mares were used during the breeding seasons of 2012, 2013 and 2014. Placentitis was induced by intra-cervical infusion of Streptococcus equi subspecies zooepidemicus between days 280-295 of gestation. Hormone therapy together with clinical evaluation started 48 hours after induction and the mares were divided into groups according to the therapy administered: G1 (n = 5) non-induced mares; G2 (n = 5) mares with induced placentitis treated with antibiotic therapy and anti- inflammatory (sulfamethoxazole and trimethoprim -SMT + Flunexin Meglumine -FM); G3 (n = 5) mares with induced placentitis treated with SMT + FM plus estradiol cypionate (ECP); G4 (n = 5) mares with induced placentitis treated with SMT + FM plus ECP and Altrenogest; G5 (n = 5) mares with induced placentitis treated with SMT + FM plus Altrenogest; G6 (n = 5) untreated mares. After assisted delivery, histological samples were obtained from four points on each placenta for the portion of the cervical star; pregnant horn; non-pregnant horn and uterine body. The slides were evaluated by optical microscopy, scanned and processed using NIH ImageJ 1.48r software. The mean microcotyledon capillary area of the portion referring to the cervical star and the non-pregnant horn of G1 and G3 were higher than the other groups (p <0.05). While the mean microcotyledon capillary area of the uterine body was larger in G1, compared to the other groups. When the microcotyledon area of the pregnant horn of G1 and G3 was analyzed, they were larger than that observed in the other groups (p <0.05). The microcotyledon area of the non-pregnant horn of G1 and G3 was superior to the other groups. Thus, the group of mares treated with ECP showed a better microcotyledon response, compared to other treatments.