Serum neuropeptide concentrations in cows with intrapartum uterine torsion.

Intrapartum uterine torsion is a common cause of dystocia in dairy cows. To clarify the pathophysiology of this disease, the aim of the present study was to examine serum neuropeptide and cytokine concentrations of cows with intrapartum uterine torsion. Blood samples of 20 cows with uterine torsion, 36 healthy controls, and 15 intrapartum cows without uterine torsion were obtained. Concentrations for substance P (SP), vasoactive intestinal polypeptide (VIP), and interleukin-1β (IL-1β) were quantified by using commercially available ELISA kits. Significant differences between groups were observed for SP in cows with uterine torsion and cows calving normally (P <  0.01). Markedly greater SP concentrations were observed in calving cows than in cows with uterine torsion. Compared with healthy controls, there were greater SP concentrations during parturition (P <  0.01). No significant group differences were detected for VIP concentrations. Global differences were observed in IL-1β (P =  0.04). Large amounts of SP are released into the blood during parturition. Because SP is mainly present within the cervix and functions as a biomarker and mediator of pain, cows with uterine torsion are presumed to not experience as much pain as cows that are calving normally. Consistent with this, in cows with uterine torsion, there is a disturbance in the opening of the cervix, along with only mild signs of colic. Furthermore, significantly elevated IL-1β concentrations correlate with the inflammation that occurs in cases of uterine torsion. Further research is needed to support these findings and clarify the clinical relevance.