Comparative anti‐inflammatory effects of insulin and dexamethasone on cardiovascular biomarkers and antioxidants in miniature donkeys subjected to induced carbohydrate overload.

Summary: Background: Inflammatory responses as a result of carbohydrate (CHO) engorgement have been associated with peripheral tissue insulin resistance. Objectives: The aim of this study was to comparatively evaluate the anti‐inflammatory effects of intravenous (i.v.) administration of insulin and dexamethasone on clinical parameters, antioxidants and cardiovascular biomarkers in miniature donkeys subjected to induced CHO overload. Study design: Prospective, experimental study. Methods: Eighteen clinically healthy male miniature donkeys with the age of 5 ± 1 years, weight of 105 ± 6 kg, body condition score of 5 (moderate) and height at the withers of 0.9 ± 0.06 m were used for this study. The animals were randomly assigned into three experimental groups (2 treatments and 1 negative control). Oligofructose (OF) at 10 g/kg of bodyweight was administered via nasogastric tube to induce CHO overload. Six hours later, animals in the treatment groups received IV 3 IU/kg bwt of insulin and 2 mg/kg bwt dexamethasone, respectively. Results: The results of this study revealed that heart rate (HR), respiratory rate (RR) and rectal temperature (RT), packed cell volume (PCV), white blood cell (WBC), glucose, homocysteine (Hcy) and cardiac troponin I (cTnI) increased, while the values of superoxide dismutase (SOD) and glutathione peroxidase (GPX) decreased in miniature donkeys subjected to CHO engorgement. All variables (except PCV) returned to normal values within 24 h in treatment groups. In treatment groups, HR and RR were significantly lower than the control group after 12 h. There were no significant differences between insulin and dexamethasone in levels of cTnI, Hcy, SOD, GPX, glucose, PCV and WBC after 24 h. Main limitations: Recording of only antioxidants and cardiovascular biomarkers is insufficient to well define the anti‐inflammatory effects of insulin. Conclusions: It could be suggested that insulin (3 IU/kg bwt) and dexamethasone (2 mg/kg bwt) may be useful during CHO overload in miniature donkeys. [ABSTRACT FROM AUTHOR]