Untersuchung TNF-[alpha]-vermittelter Effekte auf präovulatorische Ovarien von Jungsauen
2009
The
process of ovulation has been linked to an inflammatory reaction, which
includes the infiltration of different leukocyte populations into the tissue
of mature Graafian follicles, the activation of resident
immune cells and the local production of cytokines. Hypothetically, cytokines
produced in the nearby uterus may reach the ovary via a so called counter
current transfer, in parts where the uterus vein is neighboured by the arteria ovarica.
In the present
study, we tested the hypothesis that TNF-α reaching the porcine ovary
via the arteria ovarica
triggers resident mast cells and thereby induces degranulation and mediator secretion which eventually
promote preovulatory events.
A
bilateral surgical approach in the pig using 14 spontaneous cycling gilts was
used. Recombinant porcine TNF-α at 2 or 20 ng
in one ml was injected into the ovarian artery of one side and PBS into the contralateral side up to 10 h after the detection of
oestrus. The ovaries were ectomized 45 min later.
Follicular fluid was aspirated and analysed for histamine concentrations.
Ovarian tissue was dissected into four regions to be analysed by histology, immunohistochemistry and quantitative RT-PCR. The Pappenheim stain was used for the quantitative analysis
of mast cells. Immunohistochemistry was performed
using specific anti-TNF-α and anti-TNF-α receptor I
antibodies. The mRNA expression of eight chemokines,
cytokines and enzymes
(TNF-α, GM-CSF, TGF-s, IL-10, CXCL8, IL-6, PTGS2, lipoxygenase-5) was
analysed by qRT-PCR.
An in
vivo model for delivering cytokine-mediated effects to the porcine ovary was
established successfully. In this study no evidence was found for a direct
action of mast cell-mediated TNF-α dependent effects
on preovulatory follicles. Nontheless,
we cannot rule out, that TNF-α may influence preovulatory
follicles in the porcine system - a variety of cells located in ovarian
tissue may act as a target for direct TNF-α mediated effects. The selective upregulation of the pro-inflammatory PTGS2 and the
selective down-regulation of other pro-inflammatory mediators (TNF-α, CXCL8) caused by TNF-α-application indicates that the ovulatory cascade is not a classical inflammatory
response.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
0
References
0
Citations
NaN
KQI