Evaluation of oxidant-antioxidant status, serum cytokine levels and some cardiac injury biomarkers in acute ruminal lactic acidosis in goats

- A probable role of lipid peroxidation and depleted antioxidants (SOD, CAT, GSH, TAC), in the pathogenesis of acute ruminal lactic acidosis in goats, is proposed.
- Oxidative radicals induce greater expression of serum cytokines (TNF-α, TGF-β, IL-10) in lactic acidotic goats, these cytokines possess diagnostic and prognostic values.
- Quantification of lactate dehydrogenase (LDH) and creatine kinase isoenzyme MB (CK-MB) aids in the evaluation of myocardial injury inflicted on goats, during acute ruminal lactic acidosis.

Fifteen goats clinically diagnosed with acute ruminal lactic acidosis (ARLA group) and fifteen healthy goats (control group) were included in the study. The samples of whole blood and rumen liquor were collected for the analysis of oxidative stress indices, serum cytokines, cardiac biomarkers and intraruminal changes. The acidotic goats showed moderate to severe dehydration, elevation of pulse and respiration rates, ruminal atony, reduced population of ruminal protozoa and a marked increase in ruminal glucose concentration. Compared to the control group, ARLA group had a significantly higher (p < 0.0001) level of malondialdehyde (MDA), a marker of lipid peroxidation (LPO), whereas the activities of catalase (CAT) and superoxide dismutase (SOD), total antioxidant capacity (TAC) and levels of reduced glutatione (GSH) were significantly lower (p < 0.0001) in ARLA goats. The secretion of tumour necrosis factor (TNF)-α and transforming growth factor (TGF)-β (pro-inflammatory cytokines) and an anti-inflammatory cytokine, interleukin (IL)-10, was significantly increased (p < 0.0001) in goats with ARLA, with the highest increase in TGF-β. A significant elevation (p < 0.001) of creatine kinase isoenzyme MB (CK-MB) and lactate dehydrogenase (LDH) was detected in goats with ARLA as compared to healthy goats. These results highlight the occurrence of oxidative stress with a notable decrease in antioxidant defenses, increased expression of several inflammatory cytokines and the myocardial injury induced during ARLA in goats.