Plasma glucose and cortisol responses to exogenous insulin in fasted donkeys.
- Comparative Study
- Journal Article
Summary
The research explores the impact of fasting on insulin sensitivity and the consequent glucose and cortisol responses in donkeys. The results indicate that fasting for three days reduces both the rate of insulin-induced hypoglycemia and the maximal hypoglycemic response, increasing the risk of equine hyperlipaemia.
Objective & Methodology
This study was conducted to determine the effects of changes in insulin sensitivity in donkeys due to varying periods of fasting. It investigated:
- The glucose and cortisol responses to an insulin challenge.
- The changes in these responses after different fasting durations.
The trial was performed on six donkeys, which were fasted overnight or for three days. The intravenous insulin challenge was administered at 0.4 IU kg-1 bodyweight. The responses observed were compared with reactions after saline administration.
Findings
The main findings suggest that:
- Three days of fasting lowered the rate of insulin-induced hypoglycemia and the maximal hypoglycemic response.
- There was a temporary rise in plasma cortisol, which peaked within one to four hours of administering insulin. This was observed in half of the overnight fasted donkeys and all the donkeys that were fasted for three days.
- There existed inter-animal variation in the responsiveness of the hypothalamic-pituitary-adrenocortical (HPA) axis to insulin-induced hypoglycemia stimulation.
Interpretation & Implications
The results highlight how fasting can affect insulin sensitivity and thus the regulation of blood glucose levels in donkeys. The reduced tissue sensitivity to the glucoregulatory action of insulin suggests that fasting may enhance the risk of equine hyperlipaemia. Equine hyperlipaemia is a severe metabolic disorder in horses and donkeys that can result in organ damage and potentially lead to death. This study implies that care must be taken when instituting fasting in donkeys due to the potential risk of developing this condition.
Cite This Article
Publication
Researcher Affiliations
- Department of Veterinary Clinical Science and Animal Husbandry, University of Liverpool, Neston, South Wirral.
MeSH Terms
- Animals
- Blood Glucose / analysis
- Blood Glucose / metabolism
- Equidae / blood
- Equidae / physiology
- Fasting / physiology
- Food Deprivation / physiology
- Horse Diseases / metabolism
- Horse Diseases / physiopathology
- Horses
- Hydrocortisone / blood
- Hypoglycemia / metabolism
- Hypoglycemia / physiopathology
- Hypoglycemia / veterinary
- Hypothalamo-Hypophyseal System / physiology
- Insulin / pharmacology
- Insulin Resistance / physiology
- Male
- Pituitary-Adrenal System / physiology
- Radioimmunoassay / methods
- Radioimmunoassay / veterinary
Citations
This article has been cited 4 times.- Timko KJ, Hostnik LD, Watts MR, Chen C, Bercz A, Toribio RE, Belknap JK, Burns TA. Diagnostic evaluation of insulin and glucose dynamics in light-breed horses receiving dexamethasone.. Can Vet J 2022 Jun;63(6):617-626.
- Gehlen H, Schwarz B, Bartmann C, Gernhardt J, Stöckle SD. Pituitary Pars Intermedia Dysfunction and Metabolic Syndrome in Donkeys.. Animals (Basel) 2020 Dec 8;10(12).
- Durham AE, Frank N, McGowan CM, Menzies-Gow NJ, Roelfsema E, Vervuert I, Feige K, Fey K. ECEIM consensus statement on equine metabolic syndrome.. J Vet Intern Med 2019 Mar;33(2):335-349.
- Hayirli A. The role of exogenous insulin in the complex of hepatic lipidosis and ketosis associated with insulin resistance phenomenon in postpartum dairy cattle.. Vet Res Commun 2006 Oct;30(7):749-74.
