Doctoral Dissertations
Date of Award
12-2023
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Major
Comparative and Experimental Medicine
Major Professor
Marc Caldwell
Committee Members
Gina Pighetti, Stephen Kania, Chika Okafor
Abstract
Recent developments in sepsis treatment showed that control of the late mediator of inflammation, High Mobility Box group-1 (HMGB1), improves survival in animal models of endotoxemia. Ethyl pyruvate is a small-molecule inhibitor that has been shown to reduce the systemic release of HMGB1 during experimental treatment of systemic inflammation in different species. The objectives of this body of work were 1) to explore ethyl pyruvate's ability to modulate early pro-inflammatory cytokines production and immune effector function in treated calves, 2) to evaluate the safety of an administration of ethyl pyruvate infusion in neonatal calves, and 3) to explore ethyl pyruvate's ability to modulate pro-inflammatory cytokines production in vitro in neonatal calves' whole blood samples. The first study includes 24 calves randomly assigned to 1 of 3 treatment groups of 8 calves per group: (1) Placebo control – one liter of lactate ringer solution (2) ethyl pyruvate at 50 mg/kg infusion within one liter of lactated ringer solution; (3) ethyl pyruvate at 100 mg/kg infusion within one liter of lactated ringer solution. Treatments were given over 30-45 minutes. Blood samples were collected in EDTA and lithium heparin tubes before infusion time and at 1-, 3-, 6-, 12-, 24- and 48-hours post-infusion. Each sample was split, and one aliquot was incubated at 37°C for an hour with 1 ng/ml of E. coli lipopolysaccharides (Escherichia coli O55:B5) solution. Pro-inflammatory cytokines, TNF-α, IL-1β, IL-6, and HMBG1, were measured in plasma. Granulocyte phagocytosis activity was measured at all time points. Ethyl pyruvate treatment did not significantly affect cytokine concentrations at 50 and 100 mg/kg.
Furthermore, evaluation of in vitro ethyl pyruvate at different concentrations in whole blood showed that higher concentration could increase cytokine production by immune cells and reveal a dose-dependent effect on the production of pro-inflammatory cytokines. The results of this dissertation do not support the hypothesis that ethyl pyruvate could alleviate the release of pro-inflammatory cytokines following an in vitro endotoxemia challenge in dairy calves. For this reason and due to possible safety concerns, it should not be used clinically in neonatal dairy calves at this point.
Recommended Citation
Dore, Vincent, "Ethyl pyruvate failed to reduce pro-inflammatory cytokines release following in vitro stimulation in dairy calves' whole blood.. " PhD diss., University of Tennessee, 2023.
https://trace.tennessee.edu/utk_graddiss/9192