Abkürzungen - Stiftung Tierärztliche Hochschule Hannover

7. Summary
Alexandra Görgens:
Influence of repeated artificial insemination and sperm components on properties of
uterine neutrophilic granulocytes of mares
Coitus or artificial insemination (IS) in mares is always followed by an immigration of
leukocytes into the endometrium and into the uterine lumen which is dominated by
polymorphonuclear neutrophilic granulocytes (PMN). This physiological reaction aims at the
elimination of residual spermatozoa and contaminating bacteria.
After breeding, some mares develop a persistent endometritis, resulting in poor pregnancy
rates. PMN are considered to play an important role in the pathogenesis of these breeding-
induced, persistent endometritis. Rather few is known about the dynamics of the PMN influx
into the uterus, especially after repeated IS, and about factors which exert an influence on this
process. Further, less is known about the functional properties of intrauterine PMN.
At first, an animal model for the simulation of a repeated IS has been established. The aim
was to generate a methodological tool which allows for the quantification and characterization
uterine PMN functionality after single or repeated IS as well as the analysis of the respective
pregnancy rates. Initial experiments showed that intrauterine application of fresh semen and
of the chemokine recombinant human Interleukin 8 (rhIL-8) result in a comparable PMN
influx into the uterus. As already known from previous work with rhIL-8, fresh semen
provoked maximal intrauterine PMN numbers six hours after IS, a number which is still
elevated after 48 hours. Therefore, for simulated repeated IS, mares were infused with rhIL-8
on day 1 and 24 hours later inseminated with fresh semen. Mares of the control group
received a single IS of fresh semen. To harvest uterine leukocytes, the uterus was flushed six
hours after IS (or after infusion with rhIL-8) with phosphate buffered saline (PBS) – a
technique similar to the embryo transfer technique.
Flow cytometric methods were used to quantify immigrated uterine leukocytes as well as to
test their viability, their morphology, their phenotype and their phagocytic capacity. All
parameters were compared with contemporary separated blood PMN.
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