Interleukin 8 in the cervix of non-pregnant ewes

Abstract

Studies of cervical artificial insemination of ewes at hormone-synchronized oestrus indicate that the cervix remains relatively impenetrable to semen, in contrast to naturally breeding animals. During parturition the inflammatory response plays an important part in cervical dilation and possibly, to a lesser extent, in the non-pregnant cervix at oestrus to facilitate the transcervical transport of semen. The expression of interleukin 8 (IL-8), a pro-inflammatory cytokine in the ovine cervix, has been mapped and quantified, using semi-quantitative in situ hybridization, to ascertain the role played by inflammation in the ovine cervix during natural and artificially induced oestrous cycles. IL-8 gene expression was observed in both the luminal epithelium and fibroblastic cells of the cervix. The presence of IL-8 was confirmed using immunohistochemistry. IL-8 gene expression in the luminal epithelium varied throughout the oestrous cycle and was highest at oestrus and at day 5 of the oestrous cycle. In ewes artificially induced to ovulate, either by the withdrawal of progesterone pessaries after treatment for 12 days, or by two i.m. injections of prostaglandin 9 days apart, IL-8 gene expression at oestrus was significantly lower than it was at natural oestrus. Insemination increased IL-8 gene expression in progesterone-synchronized ewes. These data support the hypothesis that IL-8-induced inflammation is important in normal cervical function and that this process is inhibited during artificial synchronization of the oestrous cycle and is increased by exposure to semen.

Canine pyometra: a model for the analysis of serum CXCL8 in inflammation

“…Since CXCL8 is fundamental for the migration and activation of neutrophils, it is expected to be elevated in diseased animals [ 3 , 6 , 31 ]. Serum CXCL8 levels in dogs with pyometra have seldom been analyzed, but it has been shown that various cell types within the uterus produce CXCL8 in response to diverse stimuli, including pyometra [ 5 , 11 , 16 , 30 ]. The source of CXCL8 measured in sera is unknown and so, a local as well as a systemic secretion has to be taken into consideration.…”

“…Second, low serum CXCL8 values can be due to a poor or depleted immune response and thus be related to severe symptoms. Third, progesterone is an inhibitor of CXCL8 in uteri and makes this organ more susceptible to infection [ 5 , 16 , 28 , 29 , 31 ]. If the CXCL8 in sera stems from the uterus, its decrease may be the result of high progesterone concentrations.…”

Ovine feto‐placental metabolism

“…In the current study, there were no apparent differences in the abundance or localization of GLUT‐1 and GLUT‐3 mRNA in placentomes following cortisol infusion. In situ hybridization is widely accepted as a sufficiently robust and accurate method for quantifying gene expression and has the added advantage of establishing the cellular localization of the specific mRNAs (Gadd et al 2000; Mitchell et al 2002). Although further studies are required to determine whether cortisol affects expression of GLUT proteins in ovine placentomes, the current observations suggest that changes in transporter abundance are unlikely to make a major contribution to the cortisol‐induced decrease in umbilical glucose uptake.…”

Leptin receptor gene expression and number in the brain are regulated by leptin level and nutritional status

“…Automated sequencing was performed to verify the sequences. Messenger RNA levels were quantified by in situ hybridisation, on 20 μm thick coronal hypothalamic cryo‐sections, using techniques described in detail elsewhere (Mitchell et al 2002). Briefly, slides were fixed in 4% (w/v) paraformaldehyde in 0.1 mol l −1 phosphate‐buffered saline (PBS) for 20 min at room temperature, washed in PBS, incubated in 0.1 mmol l −1 triethanolamine for 2 min and acetylated in 0.1 mmol l −1 triethanolamine and 0.25% (v/v) acetic anhydride for 10 min.…”