Effects of intravenous infusion of E.coli lipopolysaccharide in early pregnant cows

The objective was to characterize effects of Escherichia coli LPS (given iv) on corpus luteum (CL) and embryonic viability in early pregnant cattle. Eight non-lactating German Holstein cows were given 0.5 µg/kg LPS on 35 ± 3 d (mean ± SEM) of pregnancy, whereas seven heifers, 41 ± 6 d pregnant, were given 10 ml saline (Control group). Transrectal B-mode examinations of the CL were done at -1, 3, 6, 12, 24, 48, 72, and 96 h relative to treatment. Blood samples were collected at -1, 0.5, 1, 2, 3, 4, 6, 9, 12, 24, 48, 72, and 96 h. At 12 and 48 h, the CL was biopsied. None of the cows still in the experiment 10 d after LPS (n=7) had embryonic loss. In LPS-treated cows, luteal area decreased (from 4.1 to 3.1 cm2; P≤0.05) within 6 h and until 48 h. Luteal blood flow decreased by 39% (P≤0.05) within the first 6 h after LPS, but returned to pre-treatment values by 48 h. Plasma P4 decreased by 62% (P≤0.05), reached a nadir (2.7±0.6 ng/mL) at 12 h after LPS and was not restored to pre-treatment (P≤0.05). In luteal tissue, mRNAs for StAR and for FGF1 were lower (P≤0.05) in LPS- than in saline-treated cattle at 12 h, with no difference between groups at 48 h. Levels of mRNAs for Casp3 and FGF2 were not different between groups (P>0.05) at 12 or 48 h after treatment. In conclusion, LPS transiently suppressed CL function, but did not induce embryonic mortality

Effects of induced endometritis on uterine blood flow in cows as evaluated by transrectal Doppler sonography

This study was conducted to evaluate the effects of induced endometritis on uterine blood flow in cows. Transrectal Doppler sonography was performed on uterine arteries of six cyclic cows before and for 4 days after inducing acute endometritis by intrauterine infusion of 720 mg of policresulen, and for 4 days of the following estrous cycle. Time-averaged maximum velocity (TAMV) increased (p 0.05) in the next 4 days of the same cycle. TAMV and PI values in the subsequent cycle did not differ (p > 0.05) from the values measured before infusion and showed no changes (p > 0.05) within the cycle. Blood flow parameters were not related (p > 0.05) to plasma concentrations of progesterone and estrogen. All cows showed an acute endometritis determined by histopathological findings of biopsy samples taken 1 day after infusion and fibrotic endometrial alterations detected in the subsequent cycle. No relationships were observed between fibrotic changes of the endometrium and uterine blood flow during either cycle. In conclusion, acute inflammation is accompanied by a rise in uterine blood flow, but fibrotic alterations do not seem to be related to Doppler sonographic findings