The effect of semen extender supplemented with pentoxifylline on post-breeding inflammation response assessed by endometrial cytology

Abstract

Since pentoxifylline appears to participate from two concurrent methods of action: as rheological agent, improving blood flow to compromised tissues, and as immunomodulatory agentit was hypothesized that pentoxifylline could participate positively on post-breeding inflammation response. The aim of this study was to evaluate, through cytology, the uterine inflammatory response caused by pentoxifylline added to skim milk extender. Thirty five cycles from 15 mares were utilized. When diagnosed in estrus mares were examined daily via transrectal palpation and ultrasound examination, when the dominant follicle reach 35 mm in diameter, 2500 IU of hCG (Vetecor ) intravenously, was administered. After 30 hours, ultrasound examinations were made every 6 hours, in order to inseminate mares immediately after ovulation. For artificial insemination, mares were randomly divided into 5 groups: C (control): no deposition of semen, nor extender, just mimicking the AI procedure (n1⁄47); E: deposition of skim milk based extender (Botusemen , Botupharma) (n1⁄47); EP: deposition of skim milk based extender plus pentoxifylline (7.18 mM, Sigma-Aldrich) (n1⁄47); S: deposition of semen with skim milk based extender (without pentoxifylline) (n1⁄47); and SP: deposition of semen withskim milk based extender containing pentoxifylline (7.18 mM) (n1⁄47). The inseminate dose wasa total of 1x109 sperm and 50% of motility. Endometrial samples were collected at six hours after insemination. Samples were collected rotating the cytobrush, in contact with the uterine wall. Slides for cytology were prepared by rolling the cytobrush onto a glass microscope slide and airdried, stained using Panotico Rapido (Laborclin Ltda.), airdried and examined by light microscopy at 400x magnification. Three hundred cells per slide were examined and classified as endometrial epithelial cells and polymorphonuclear cells (PMN). Inflammatory response was gradednormal ( 75% of PMN). All variables were analyzed byanalysis of variance, and the range was compared by LSD test, using SAS 9.3 version (2010). This study clearly shows a major (p 0.05), but both showed more (p<0.05) PMN than E group. In addition, the SP group showed major (p<0.05) inflammatory response than EP group. Nevertheless, the Control group (C) was statistically different (p<0.05) only from SP group. In conclusion, pentoxifylline does stimulate a greater mechanisms defense, since increased neutrophils migration to uterine lumen whereas may promote faster endometrial recovery.