S. Acuña1*, C. López1, E. Fumuso2, M. Herrera2, E Rodríguez2, D. Rogan3, C. Tasende1

1*Veterinary faculty, Montevideo, Uruguay, 2Faculty of Veterinary Science, Tandil, Argentina, 3Bioniche Life Sciences Inc., Belleville, Ontario, Canada.

1*saap22@ adinet.com.uy

EFFECT OF IMMUNOMODULATION ON OXYTOCIN RECEPTOR IN THE ENDOMETRIUM OF HEALTHY EFFECT OF IMMUNOMODULATION ON OXYTOCIN RECEPTOR IN THE ENDOMETRIUM OF HEALTHY ENDOMETRITIS RESISTANT MARES ENDOMETRITIS RESISTANT MARES

Materials and MethodsMaterials and Methods

ResultsResults

AcknowledgementsAcknowledgements

To: P. Rubianes for technical assistance.

The distribution of endometrial oxytocin receptor, in mares treated with an immunomodulator during estrous cycle has not been

document. Our purpose was to investigate the distribution of endometrial oxytocin receptor in the endometrial of healthy mares

resistant to endometritis treated with an immunomodulator

1. Fumuso E., et al. (2003). Vet. Immun. and Immunopat. 96: 31-41.

2. Acuña S., et al. (2008). ICAR Congress.

ReferencesReferences

An immunoperoxidase staining technique was used to visualize Oxytocin Receptor (ROx) immunoreactivity in the endometrial of healthy resistant mares to endometritis, during of the estrous cycle (Fig. 1).

The staining of ROx was observed in the luminal epithelium (LE), superficial glandular epithelium (SGE) and deep glandular epithelium (DGE) (Fig. 2).

The average staining intensity was analyzed by ANOVA; including effect the epithelial type, stage of estrous cycle and interaction between these as the main interactions (Fig. 3).

Fig. 2. Immunohistochemical localization of ROx in the endometrium of HRM. (A)= epithelial localization in biopsies (100x), (B)= negative control (400x), (C)=ROx positive sample showing LE and SGE cells (400x) and (D) ROx positive sample showing DGE (400x).

At the level in the endometrium of mares susceptible to endometritis, the response to immunomodulation with MCC-V has proven to be

beneficial by modulating the inflammatory response (1). Besides its effect on HRM, MCC-V has been shown to increase the presence of

endometrial tissue leukocytes for 24 hours post-treatment (as happens after breeding) with no negative effects on estradiol or progesterone

receptors (2).

The decline in ROx during ovulation and early diestrus confirms previous findings, and demonstrates the lack of any adverse effect associated

with the use of MCC-V in HRM.

These data suggest that prophylactic immunomodulation with MCC-V could be safely used in HRM; particularly for embryo

transfer or when breeding with expensive semen.

Discussion and ConclusionDiscussion and Conclusion

Fig. 3. Staining intensity for ROx in endometrial tissue of HRM during the estrous cycle treated at oestrous with MCC-V intrauterine administration. Bars (means ± standard errors) a,b,c are significant differences between epithelial types and * E is different to 24hPT, OvPT and d6POv. P<0.05.

Healthy endometritis resistant mares (HRM, n=7), received 1500µg of an immunomodulator (mycobacterial cell wall-DNA complex (MCC-V), Bioniche Life Sciences Inc., Canada), by intrauterine administration at the beginning of estrus.

Fig. 1. Days that biopsies samples were taken for ROx determinations. O: Oestrous (ovarian follicles >29 mm, fold and endometrial oedema) immediately before treatment with MCC-V; 24hPT: 24 h post treatment; OvPT: around the ovulation (± 12h) and d6POv: diestrous (6 days after ovulation). The follicular dynamic was followed by ultrasonography.

C

A B

C D

LE

SGE

DGE

LE

SGE

LE

SGE

DGE

Differences in ROx expression between epithelial type (P<0.001) and stage of the estrous cycle was observed (P<0.05). The greatest intensity of staining was found in DGE, was intermediate in LE and was lowest in SGE at all stages of the estrous cycle. In all three epithelia tested, staining intensity decreased (P=0.008) from O to 24hPT, and there were no differences between 24hPT, OvPT and d6POv. (Fig. 3)

a,*

b,*

c,*

a

b

c

a

b

c

a

b

b

STAGES OF THE ESTROUS CYCLE

ENDOMETRI AL BI OPSI ES FOR I MMUNOHI STOCHEMESTRY

Ostrous(O, n=7)

MCC-V

24 h post-treatment (24 hPT, n=7)

Time of ovulation (±12h)(OvPT, n=6)

Six days af ter ovulation (d6POv, n=5)

STAGES OF THE ESTROUS CYCLE

ENDOMETRI AL BI OPSI ES FOR I MMUNOHI STOCHEMESTRY

Ostrous(O, n=7)

MCC-V

24 h post-treatment (24 hPT, n=7)

Time of ovulation (±12h)(OvPT, n=6)

Six days af ter ovulation (d6POv, n=5)

0

0,5

1

1,5

2

E 24hPT OvPT d6POv

Times of the oestrous cycle

Sta

inin

g in

tens

ity

LE SGE DGE

O