Pro-inflammatory Cytokine Gene Expression in Endometrial Cytobrush Samples Harvested from Cows With and Without Subclinical Endometritis

A detailed understanding of the postpartum cow’s uterine immune responses is lacking due to difficulties in obtaining endometrial tissue. Our objectives were to develop a minimally invasive cytobrush technique to collect endometrial cells in postpartum cows (28 to 41 days in milk; DIM) for the isolation of mRNA, and to characterize the expression of key regulatory cytokines including: IL-6, IL-8 and TNFα. Cows without clinical signs of endometritis were subdivided into those with a negative or positive (defined as >18% neutrophils) endometrial cytobrush cytology. Thirty Holstein cows were sampled from six commercial dairies. A modified cytobrush was double guarded and advanced into the cervix, passed through the cervical canal and advanced into the uterine body, rotated 360 degrees and retracted into its sheath before removal from the reproductive tract. [...]