Effect of Lipopolysaccharide Infusion on Serum Macromineral and Vitamin D Concentrations in Dairy Cows

Abstract

Four multiparous lactating cows (175 to 220 d in milk) were used in a 4 x 4 Latin square design to assess the effects of four doses (0.0, 0.5, 1.0, 1.5 microg/kg of body weight) of lipopolysaccharide (LPS; Escherichia coli 0111:B4) on circulating concentrations of macrominerals and vitamin D metabolites. Treatments were dissolved in 100 ml of sterile saline and infused intravenously over a period of 100 min. Blood was sampled immediately before infusion (0 h), at 60-min intervals for 8 h, and at 24 and 48 h postinfusion. Vitamin D metabolites were analyzed in samples collected at 0, 2, 6, 24, and 48 h only. Serum Ca and P concentrations decreased after LPS infusion, but there was no effect on serum magnesium concentration. Plasma 25-OH vitamin D3 and 1,25-(OH)2 vitamin D3 were not affected by LPS infusion; however, when analyzed as 0 vs. all other doses of LPS combined, there was a tendency for plasma 1,25-(OH)2 vitamin D3 concentration to decrease when cows were infused with LPS. The inflammatory response elicited by LPS altered plasma macromineral concentrations, a result that may have important implications for calcium homeostasis and metabolic health of lactating dairy cows.

Nutrition, microbiota, and endotoxin-related diseases in dairy cows

“…We postulate that endotoxemia might have played a role in the hypocalcemia of the sick cow in our study. This assumption is supported by greater LBP concentrations found in the plasma of DC as well as by the fact that administration of LPS is associated with lower plasma Ca in dairy cows (Waldron et al, 2003). The sick cow also showed greater plasma Zn compared to reference values, which suggest inability of the sick cow to maintain Zn homeostasis.…”

“…On the other hand, plasma calcium helps creation of endotoxin aggregates, therefore, withdrawal of plasma calcium may help the process of monomerization and clearance of endotoxin through lipoprotein pathway (Munford et al, 1981). Indeed, Waldron et al (2003) reported that experimental endotoxemia was associated with hypocalcemia. It is not clear whether lowering of plasma calcium occurs because calcium binds endotoxin to neutralize its biological effects as suggested by Garidel et al (2005) or because calcium mobilization is impaired during administration of endotoxin (Zaloga et al, 1992).…”

Regulation of Mycobacterium-Specific Mononuclear Cell Responses by 25-Hydroxyvitamin D3

“…In the vitamin D endocrine system, 1α-OHase is expressed in the kidney and is tightly regulated in response to calcium homeostasis via the parathyroid hormone in order to control the circulating concentration of 1,25(OH) 2 D 3 [37]. However, the circulating concentration of 1,25(OH) 2 D 3 does not affect vitamin D-mediated immune responses [38], [39] and circulating 1,25(OH) 2 D 3 does not increase when the immune system is activated [40]. Rather, monocytes and macrophages express 1α-OHase in response to toll-like receptor (TLR) signaling, and this has been shown for humans, cattle, and mice [20], [41], [42].…”

Effects of intravenous infusion of lipopolysaccharide on plasma micromineral, magnesium, and cytokine concentrations and serum cortisol concentrations in lactating goats

“…The experimental design used in our study was selected according to that of a recent study on cows by Waldron et al 20 Lipopolysaccharide doses were chosen on the basis of our preliminary test results, in which the doses used resulted in only short-acting systemic signs such as fever and decreased activity in goats. Goats were allotted to 3 LPS-treatment groups as follows: control (0 µg/kg), low LPS (10 µg/kg), and high LPS (50 µg/kg), with 6 goats/group.…”

“…11,12 Biological actions of LPS are mainly caused by triggering the production and release of endogenous mediators of inflammation, including the secretion of cytokines such as TNF-α and IL-6. The inflammatory response elicited by LPS reduces plasma calcium and phosphorus concentrations in dairy cows 20 and lactating sows. 16 Study of the physiologic effects of LPS infusion could provide a pathophysiologic paradigm used to extensively explore the mechanisms of manifold systemic signs of infection (fever, anorexia, and emaciation) and the reciprocal interactions between several macrophage-produced cytokines and HPA hormones.…”