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Effect of flunixin meglumine and oxytocin on uterine response to insemination in mares
Animal Reproduction Science 94 (2006) 252–253
Abstract
Effect of flunixin meglumine and oxytocin on uterine response to insemination in mares夽 T. Reilas a,∗ , A.M. Risco b , M. Kareskoski c , T. Katila c a
MTT Agrifood Research Finland, Animal Production Research, Equines, Varsanojantie 63, 32100 Yp¨aj¨a, Finland b Service of Research and Technological Development, Junta de Extremadura, Estate “La Orden”, 06071 Guadajira (Ba), Spain c University of Helsinki, Department of Clinical Veterinary Sciences, Pohjoinen Pikatie 800, 04920 Saarentaus, Finland Available online 22 April 2006
Oxytocin (OT) stimulates uterine contractions directly and indirectly via release of prostaglandin (PG). Inhibitors of PG suppress uterine contractility and decrease drainage. This study investigated the influence of flunixin meglumine and oxytocin on uterine contractions, presence of intrauterine fluid, and uterine inflammatory reaction after artificial insemination (AI) in normal mares. Treatment with flunixin, a PG-inhibitor, was used in an attempt to create a model for mares susceptible to endometritis. The mares received one of three treatments during the first oestrus. During the second oestrus, ovulation was monitored, but no treatments or samplings were done. During the third oestrus, the mares received the same treatments as in the first cycle, but the sampling times (8 or 25 h) were reversed. When a preovulatory follicle of ≥35 mm associated with uterine oedema and cervical softening was detected, a uterine swab was collected and the mare was inseminated. The mares were treated i.v. with 10 ml saline (group C, n = 10), 0.01 IU/kg oxytocin (group OT, n = 10) or 1.1 mg/kg flunixin meglumine (group FLU, n = 11) 2 h after AI. At 4, 8, and 25 h after AI, groups C and FLU were both injected with saline and group OT with oxytocin. Uterine fluid, oedema and contractions were recorded before and 4, 8 and 25 h after AI (10 min after the treatments) using B-mode ultrasonography. Video recordings of 4-min scans were used to calculate the contraction frequency/min. After 8- or 25-h scans, uterine lavage fluids were collected using 500 ml of Ringer’s solution and endometrial biopsies were obtained. At 8 h, all mares were injected with 1500 IU of hCG. The mares were examined 48 h post AI to detect ovulation and 14–17 days post AI to determine pregnancy rates. 夽 This paper is part of the special issue entitled Proceedings of the Ninth International Symposium on Equine Reproduction, Guest Edited by Margaret J. Evans. ∗ Corresponding author. E-mail address: [email protected] (T. Reilas).
0378-4320/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.anireprosci.2006.04.031
T. Reilas et al. / Animal Reproduction Science 94 (2006) 252–253
253
At 8 h after AI, group FLU had significantly more polymorphonuclear leucocytes (PMNs) in uterine lavage fluid (20.9 ± 6.3 × 106 /ml) than group OT (2.2 ± 0.5 × 106 /ml; mean ± S.E.M., p < 0.05), but not significantly more than group C (4.7 ± 1.4 × 106 /ml). At 25 h, PMN numbers were 1.8 ± 1.3, 0.1 ± 0.1 and 2.2 ± 1.3 × 106 /ml in groups FLU, OT and C, respectively. At 8 h, group FLU tended to have less contractions (1.5 ± 0.4/min) than group OT (3.1 ± 0.6/min) (p = 0.07). The mares in group OT had minimal intrauterine fluid after AI. Because of the small number of mares and wide variation in groups C and FLU, the differences were statistically not significant. Pregnancy rates did not differ between groups (60% in C, 45% in OT and 41% in FLU) or between sampling times (47% at 8 h, 53% at 25 h). Our results suggest that flunixin meglumine increases and early intervention with OT decreases the magnitude of inflammatory reaction after AI.
Abstract
Effect of flunixin meglumine and oxytocin on uterine response to insemination in mares夽 T. Reilas a,∗ , A.M. Risco b , M. Kareskoski c , T. Katila c a
MTT Agrifood Research Finland, Animal Production Research, Equines, Varsanojantie 63, 32100 Yp¨aj¨a, Finland b Service of Research and Technological Development, Junta de Extremadura, Estate “La Orden”, 06071 Guadajira (Ba), Spain c University of Helsinki, Department of Clinical Veterinary Sciences, Pohjoinen Pikatie 800, 04920 Saarentaus, Finland Available online 22 April 2006
Oxytocin (OT) stimulates uterine contractions directly and indirectly via release of prostaglandin (PG). Inhibitors of PG suppress uterine contractility and decrease drainage. This study investigated the influence of flunixin meglumine and oxytocin on uterine contractions, presence of intrauterine fluid, and uterine inflammatory reaction after artificial insemination (AI) in normal mares. Treatment with flunixin, a PG-inhibitor, was used in an attempt to create a model for mares susceptible to endometritis. The mares received one of three treatments during the first oestrus. During the second oestrus, ovulation was monitored, but no treatments or samplings were done. During the third oestrus, the mares received the same treatments as in the first cycle, but the sampling times (8 or 25 h) were reversed. When a preovulatory follicle of ≥35 mm associated with uterine oedema and cervical softening was detected, a uterine swab was collected and the mare was inseminated. The mares were treated i.v. with 10 ml saline (group C, n = 10), 0.01 IU/kg oxytocin (group OT, n = 10) or 1.1 mg/kg flunixin meglumine (group FLU, n = 11) 2 h after AI. At 4, 8, and 25 h after AI, groups C and FLU were both injected with saline and group OT with oxytocin. Uterine fluid, oedema and contractions were recorded before and 4, 8 and 25 h after AI (10 min after the treatments) using B-mode ultrasonography. Video recordings of 4-min scans were used to calculate the contraction frequency/min. After 8- or 25-h scans, uterine lavage fluids were collected using 500 ml of Ringer’s solution and endometrial biopsies were obtained. At 8 h, all mares were injected with 1500 IU of hCG. The mares were examined 48 h post AI to detect ovulation and 14–17 days post AI to determine pregnancy rates. 夽 This paper is part of the special issue entitled Proceedings of the Ninth International Symposium on Equine Reproduction, Guest Edited by Margaret J. Evans. ∗ Corresponding author. E-mail address: [email protected] (T. Reilas).
0378-4320/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.anireprosci.2006.04.031
T. Reilas et al. / Animal Reproduction Science 94 (2006) 252–253
253
At 8 h after AI, group FLU had significantly more polymorphonuclear leucocytes (PMNs) in uterine lavage fluid (20.9 ± 6.3 × 106 /ml) than group OT (2.2 ± 0.5 × 106 /ml; mean ± S.E.M., p < 0.05), but not significantly more than group C (4.7 ± 1.4 × 106 /ml). At 25 h, PMN numbers were 1.8 ± 1.3, 0.1 ± 0.1 and 2.2 ± 1.3 × 106 /ml in groups FLU, OT and C, respectively. At 8 h, group FLU tended to have less contractions (1.5 ± 0.4/min) than group OT (3.1 ± 0.6/min) (p = 0.07). The mares in group OT had minimal intrauterine fluid after AI. Because of the small number of mares and wide variation in groups C and FLU, the differences were statistically not significant. Pregnancy rates did not differ between groups (60% in C, 45% in OT and 41% in FLU) or between sampling times (47% at 8 h, 53% at 25 h). Our results suggest that flunixin meglumine increases and early intervention with OT decreases the magnitude of inflammatory reaction after AI.