Stiftung Tierärztliche Hochschule Hannover (TiHo)

Ultrasonografische Untersuchungen zur uterinen und ovariellen Hämodynamik sowie zur uterinen Kontraktionsaktivität bei der Stute unter besonderer Berücksichtigung der Besamungsfrequenz

Risse, Johannes

The objective of this work was to evaluate if there is a correlation between uterine and ovarian circulation and uterine contractile activity, and if these parameters vary with differences in insemination frequency. 38 mares were examined in 4 insemination groups (A-D). Mares of the control group were not inseminated. They were observed over the course of one complete ovarian cycle without any insemination or examined frequently without insemination after hCG injection to serve as comparisons to the inseminated animals (2 mares, resp.). With the appearance of a dominant ovarian follicle of a diameter of at least 35 mm, each animal was injected intravenously with 1500 IU human chorionic gonadotropine (hCG). Inseminations were performed in 24 h intervals, using 300 x 106 progressively motile spermatozoa (PMS) in a total dosage volume of 12 ml, respectively. The mares of group A (n = 10) were inseminated three times (D -1, 0 and 1), group B (n = 8) two times (D 0 and 1), group C (n = 10) once (D 0) and group D (n = 10) two times (D-1 and 0). Ultrasonographic examinations were performed in the same frequency in all mares according to the following pattern: Evaluation of uterine contractility in B-mode for 1 min, Colour-Doppler-sonographic measurements of blood flow in the A. uterina and the A. ovarica, and followed by examination of the circulation in the vessels within the ovarian convolute using Colour-Angio-Mode. Blood flow measurements were performed solely on the side of the ovary bearing the preovulatory dominant follicle. Parameters evaluated were: mean blood flow velocity (TAMV), volume of blood flow (BfV), resistance index (RI), pulsatility index (PI) and peak pulsatility index (PPI) and mean intensity of perfusion (mPI) especially in the A. ovarica. Mares (Group A - D) were examined: before insemination, immediately after insemination, 15 min, 30 min, 1 h,   2 h, 4 h and 6 h after insemination, resp. Over the course of the study, EDTA bloods samples were collected from the mares on a daily basis, and samples were examined for concentration of progesterone and estrogen (17-ß). Upon entering the study, mares underwent a clinical gynecological examination and acquisition of the blood sample. Uterine biopsies were taken from each animal at the beginning and the end of the study and analysed under histpathological aspects: A (D -2, 2), B (D -2, -2), C (D -2, 1), D (D -2, 1). Ultrasonographic examinations were performed using the Eccocee type SSA-340A/3E Ultrasound System manufactured by Toshiba medical systems, Japan, and a 7,0°MHz microconvex probe. Following results have been found: The overall pregnancy rate in this study was 52.6 %, while rates in the groups reached: group A 80 %, group B 50 %, group C 40 % and group D 40 % - differences were stastitically not significant. There were no significant differences in blood flow parameters between groups. TAMV in the A. uterina rose 30 min and 1 h after insemination, but decreased at 6 h reaching a level still higher than before insemination. Significant differences exist for PI and PPI after insemination (P < 0,05). PPI values were particularly low at 30 min, 1 h and 4 h after insemination, but were higher at 2 h and 6 h. TAMV was higher at time points with lower PPI values (30 min, 1 h and 4 h after insemination). On day after ovulation, blood flow increased, but remained at a lower level than pre-ovulation (P < 0,05). In mares without insemination (group K), uterine circulation decreased as well on the day of ovulation, and then increased again for a total of eight days. TAMV showed a decrease on days 9 - 13, then increased again from day 14 onwards (P > 0,05). Perfusion of the A. ovarica was lower one day after ovulation in comparison with the day of ovulation (P < 0,01); basically, blood flow in the A. ovarica during diestrus follows a curve similar to the one described for the A. uterina. Values acquired for mPI (group K) measured in the vessels within the ovarian convolute correlate with PI values measured in the ipsilateral A. ovarica. Thus, mPI increases on the day of ovulation and day 1 and 2 after ovulation, then starts to decrease for a short period of time, and during main luteal phase rises to higher levels again. Uterine contractile activity increases significantly in all insemination groups 30 min post insemination, becomes weaker at 2 h post insemination, and grows stronger again for a short period of time at 4 h. Six hours after insemination, uterine contractions are on a lower level again (P < 0,001). Repeated inseminations did not show any significant effect on uterine contractility in this study (P > 0,05). Mares which were not inseminated, but were examined in the same time intervalls as the inseminated mares, showed no increase of uterine contractile activity. Base contractile activity remained on a low level without any special characteristics. No statistically firm correlation could be established between uterine and ovarian perfusion, and the uterine contractile activity (P > 0,05). There was no correlation between uterine and ovarian perfusion, and the frequency of inseminations (P > 0,05).

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Risse, Johannes: Ultrasonografische Untersuchungen zur uterinen und ovariellen Hämodynamik sowie zur uterinen Kontraktionsaktivität bei der Stute unter besonderer Berücksichtigung der Besamungsfrequenz. Hannover 2011. Tierärztliche Hochschule.

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