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BackgroundIntrauterine infusions have been widely used for the treatment of endometritis in the mare. Nevertheless, their consequences on endocrine and endometrial molecular aspects are unknown. We studied the effect of a 1% povidone-iodine solution intrauterine infusion on progesterone levels, endometrial histology and estrogen (ERα) and progesterone (PR) receptor distribution by immunohistochemistry.MethodsFourteen healthy mares were used in this study. Estruses were synchronized and seven mares were treated with intrauterine infusions at days 0 and 2 post ovulation of two consecutive estrous cycles. Uterine biopsy samples were taken on days 6 and 15 post ovulation.ResultsThe treatment did not induce an inflammatory response indicating endometritis, neither affected the ERα. However, it reduced the percentage of PR positive cells (PPC) on day 6 (deep glandular epithelium, control: 95.7 vs. infused: 61.5, P < 0.05). Treated mares tended to have lower progesterone levels on day 2 (3.9 ng/ml vs. 6.6 ng/ml, P = 0.07), and higher levels on day 15 compared with controls (4.4 ng/ml vs. 1.3 ng/ml, P = 0.07).Conclusiona 1% povidone-iodine infusion during days 0 and 2 post ovulation in healthy mares did not induce histological changes indicating endometritis, but altered progesterone concentrations and reduced the expression of endometrial PR at day 6 without affecting the ERα. These changes could reduce embryo survival.

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The effect of side of corpus luteum on uterine gene expression and protein localization of estrogen receptor α (ERα) and progesterone receptor (PR) in healthy cyclic and pregnant mares 13 days after ovulation (day 0) was investigated. Transcervical biopsies were performed to collect endometrium ipsilateral and contralateral regarding the side of corpus luteum on day 13 post-ovulation in cyclic (n = 6) and pregnant (n = 6) mares. Blood samples were collected daily from day 0 until the day of biopsy for 17β-estradiol (E2) and progesterone (P4) determinations. Receptor expression was determined by immunohistochemistry and transcript expression by real time RT-PCR. Serum E2 and P4 concentrations were not affected by reproductive status. The contralateral horn presented higher percentage of positive cells for ERα than the ipsilateral horn (P < .05), but side did not affect PR. ERα showed low staining and no main effect of pregnancy was found, but pregnant mares had lower protein expression of PR (19.8 vs. 40.4 ± 5.3%, P < .01). The contralateral horn tended to present higher expression of ERα mRNA (1.33 vs. 0.97 ± 0.17, P < .10) and PR mRNA (1.96 vs. 1.57 ± 0.52, P < .09). ERα mRNA relative expression was lower in the pregnant group (0.88 vs. 1.44 ± 0.19, P < .05). The interaction of reproductive status and side of corpus luteum tended to affect PR mRNA expression as pregnant mares had a lower PR mRNA content in the ipsilateral horn than cyclic mares. To our knowledge, this is the first study that describes the behavior of steroid receptors in the endometrium of mares regarding side of corpus luteum.

O objetivo deste trabalho foi a avaliação da produção do leite e de seus componentes químicos de animais Corriedale e cruzas de Corriedale x Milchschaf. Foram utilizadas 33 ovelhas Corriedale, 43 cruzas Corriedale x Milchschaf (F1) e 23 cruzas F1 (Corriedale x Milchschaf) x Milchschaf (F2). Os animais foram ordenhados duas vezes ao dia, de setembro a dezembro de 2002. No total, foram realizados cinco controles leiteiros com intervalo de vinte e um dias. As amostras para composição química foram analisadas para determinação de gordura, proteína e lactose. Foi utilizado o delineamento completamente casualizado para avaliação do efeito do genótipo sobre a produção de leite corrigida para os 100 dias, e sobre a produção de gordura, proteína e lactose. No modelo matemático, a idade, o número de cordeiros ao parto e a condição corporal foram utilizadas como covariáveis. Houve diferença significativa (P<0,0001) entre os genótipos para a produção de leite (kg), gordura, proteína e lactose (g) corrigidas aos 100 dias de lactação, de modo que o genótipo F1 e F2 mostraram-se mais produtivos.