Inflammatory responses in the mammary gland after intrauterine infusion of lipopolysaccharide in dexamethasone-treated goats
Fika Yuliza Purba(1,3*), Takahiro Nii(2), Yukinori Yoshimura(2), Naoki Isobe(2)

(1)Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan
(2)Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan
(3)Veterinary Medicine Study Program, Faculty of Medicine, Hasanuddin University, Makassar, 90245, Indonesia

Abstract

Our previous study showed that intrauterine-infused lipopolysaccharide (LPS) can be translocated to the mammary gland to induce weak inflammation. This study aimed to determine if dexamethasone treatment facilitated the translocation of LPS from the uterus to the mammary gland to induce a heavy inflammatory response. Sixteen goats were divided into control and LPS groups (n = 8 each), subjected to daily dexamethasone administration before saline or LPS infusion. Milk and blood samples were collected before and after LPS infusion. Mammary gland tissues (n=2) were collected before and 24 h after LPS infusion for immunohistochemical analysis of LPS. The mean SCC in the LPS group was significantly higher, whereas the milk yield was significantly lower than that in the control group after LPS infusion. The mean BLC in the LPS group was significantly lower than in the control group after LPS infusion. Furthermore, milk concentrations of IL-1&#946-, S100A8, and lactoferrin were higher in the LPS group than in the control group after infusion. LPS was detected in the connective tissues and inner alveolar spaces of the mammary glands 24 h after LPS infusion. We concluded that dexamethasone administration facilitated the translocation of intrauterine-infused LPS to the mammary gland, where it induced an inflammatory response.

Keywords: dexamethasone, lipopolysaccharide, mastitis, cytokine, antimicrobial peptide

Topic: Veterinary Clinic, Reproduction, Pathology