<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec id="j_jvetres-2023-0011_s_005">
<h3>Introduction</h3>
<p>Metritis is a common postpartum disease in dairy cows. As a mast cell (MC) mediator, leukotriene B<sub>4</sub> (LTB<sub>4</sub>) is the strongest phagocyte chemokine. It is important in inflammation for the recruitment of immune cells to resist infection. This study investigated the effect of LTB<sub>4</sub> in metritis.</p>
</sec>
<sec id="j_jvetres-2023-0011_s_006">
<h3>Material and Methods</h3>
<p>Twenty Holstein cows 3 to 6 years old and at 6 to 10 days postpartum were selected, ten of which with postpartum metritis were the experimental group, and the other ten of which as healthy cows were the control group. The levels of LTB<sub>4</sub>, substance P (SP) and vasoactive intestinal peptide (VIP) were measured by ELISA, the expression of LTB<sub>4</sub> receptor 2 (BLT2), matrix metalloproteinase (MMP)-2 and MMP-9 mRNA was measured by qPCR, and collagens I and IV were detected by immunohistochemical staining.</p>
</sec>
<sec id="j_jvetres-2023-0011_s_007">
<h3>Results</h3>
<p>Concentrations of SP and LTB<sub>4</sub> were significantly higher, but those of VIP were significantly lower in the experimental group than those in the control group. The expression of BLT2, MMP-2 and MMP-9 mRNA was significantly higher in the experimental group than that in the control group. The expression of collagen Ⅰ and collagen Ⅳ was significantly lower in the experimental group than that in the control group.</p>
</sec>
<sec id="j_jvetres-2023-0011_s_008">
<h3>Conclusion</h3>
<p>In metritis, SP promotes the activation of MC and the synthesis and release of LTB<sub>4</sub>. Leukotriene B<sub>4</sub> chemotactic immune cells promote the high expression of collagenase, which accelerated the hydrolysis of collagen, while the inhibitory effect of VIP on MC was weakened. This may further aggravate the damage to uterine tissue.</p>
</sec>
</abstract>

Introduction
Metritis is a common postpartum disease in dairy cows. As a mast cell (MC) mediator, leukotriene B4 (LTB4) is the strongest phagocyte chemokine. It is important in inflammation for the recruitment of immune cells to resist infection. This study investigated the effect of LTB4 in metritis.


Material and Methods
Twenty Holstein cows 3 to 6 years old and at 6 to 10 days postpartum were selected, ten of which with postpartum metritis were the experimental group, and the other ten of which as healthy cows were the control group. The levels of LTB4, substance P (SP) and vasoactive intestinal peptide (VIP) were measured by ELISA, the expression of LTB4 receptor 2 (BLT2), matrix metalloproteinase (MMP)-2 and MMP-9 mRNA was measured by qPCR, and collagens I and IV were detected by immunohistochemical staining.


Results
Concentrations of SP and LTB4 were significantly higher, but those of VIP were significantly lower in the experimental group than those in the control group. The expression of BLT2, MMP-2 and MMP-9 mRNA was significantly higher in the experimental group than that in the control group. The expression of collagen Ⅰ and collagen Ⅳ was significantly lower in the experimental group than that in the control group.


Conclusion
In metritis, SP promotes the activation of MC and the synthesis and release of LTB4. Leukotriene B4 chemotactic immune cells promote the high expression of collagenase, which accelerated the hydrolysis of collagen, while the inhibitory effect of VIP on MC was weakened. This may further aggravate the damage to uterine tissue.

The role of leukotriene B<sub>4</sub> in cow metritis

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The role of leukotriene B in cow metritis

{"article-title":{"sub":4,"content":["The role of leukotriene B","in cow metritis"]}}

Introduction
Metritis is a common postpartum disease in dairy cows. As a mast cell (MC) mediator, leukotriene B4 (LTB4) is the strongest phagocyte chemokine....

Parameter	Control group	Experimental group	P-value
SP, ng/mL	308.12 ± 9.72	1258.06 ± 128.88*	P < 0.01
VIP, ng/mL	1667.34 ± 153.40	615.73 ± 70.50*	P < 0.01
LTB4, pg/mL	23.14 ± 1.12	78.84 ± 12.55*	P < 0.01

Gene/Accession number	Primer sequence	Fragment size (bp)
BLT2	Forward 5′- TTCCTCATGCGGCTCTTT -3′
NM_001191287	Reverse 5′- CCCAACCCTGACTATCCTT -3′	163 bp

MMP-2	Forward 5′- AACGCCATCCCTGATAACC-3′
NM_174745	Reverse 5′- TCACGCTCTTCAGACTTTGGT-3′	115 bp

MMP-9	Forward 5′-GCCCATTAGCACGCACGAC-3′
NM_174744	Reverse 5′-GTAGCCCACATAGTCCACCTGA-3′	118 bp

β-actin	Forward 5′-TCACCAACTGGGACGACA-3′
NM_173979.3	Reverse 5′-GCATACAGGGACAGCACA-3′	206 bp

Group	Control	Experimental	P-value
Collagen Ⅰ	2.216 ± 0. 432	1.568 ± 0. 342	P < 0.05
Collagen Ⅳ	1.946 ± 0. 365	1.493 ± 0.182	P < 0.05

The role of leukotriene B₄ in cow metritis

Online veröffentlicht: 17. März 2023

Seitenbereich: 99 - 104

Eingereicht: 17. Juni 2022

Akzeptiert: 24. Feb. 2023

DOI: https://doi.org/10.2478/jvetres-2023-0011

Schlüsselwörter
cow, metritis, leukotriene B

© 2023 G.Q. Wang et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Substance P (SP), vasointestinal peptide (VIP) and leukotriene B4 (LTB4) concentrations in the endometrium

The primer sequences and PCR product length of the target genes

Immunohistochemical analysis of types I and IV collagen in endometrium (iOD × 103, n = 10)

The role of leukotriene B4 in cow metritis

Online veröffentlicht: 17. März 2023

Seitenbereich: 99 - 104

Eingereicht: 17. Juni 2022

Akzeptiert: 24. Feb. 2023

DOI: https://doi.org/10.2478/jvetres-2023-0011

Schlüsselwörtercow, metritis, leukotriene B

© 2023 G.Q. Wang et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Substance P (SP), vasointestinal peptide (VIP) and leukotriene B4 (LTB4) concentrations in the endometrium

The primer sequences and PCR product length of the target genes

Immunohistochemical analysis of types I and IV collagen in endometrium (iOD × 103, n = 10)

The role of leukotriene B₄ in cow metritis

Schlüsselwörter
cow, metritis, leukotriene B