Plasma citrulline, arginine, nitric oxide, and blood ammonia levels in neonatal calves with acute diarrhea

Gultekin, Mehmet; Voyvoda, Huseyin; Ural, Kerem; Erdogan, Hasan; Balikci, Canberk; Gultekin, Gamze

ARG is the only substrate for synthesis of NO. 19 Approximately 80% of CIT is converted to ARG in the kidneys and plays an important role in providing an ARG/NO balance through different mechanisms. 7, 16 Ammonia is a toxic compound and excessive blood ammonia concentration might result in respiratory alkalosis, cerebral edema, seizures, coma, and death. 20, 21 CIT and ARG play a key role in detoxifying ammonia in the urea cycle. 21 Deficiencies of CIT and ARG might underlie the negative consequences of inflammatory conditions, such as sepsis and endotoxemia. 13, 16, 17 In veterinary medicine, plasma CIT concentration has only been investigated to demonstrate acute small bowel injury and measure its prognostic significance in dogs with parvoviral enteritis. 22 Therefore, this study aimed to compare plasma CIT, ARG, and NO and whole blood ammonia concentrations in neonatal calves with acute diarrhea to those in healthy calves and to evaluate their possible associations with diarrhea-related criteria. We hypothesized that neonatal calves with acute diarrhea would have reduced plasma CIT and ARG concentrations and increased plasma NO and blood ammonia, resulting from intestinal damage.