Effects of Exenatide on Plasma Glucose and Insulin Concentrations in Alpacas

Background: Exenatide is a degradation-resistant glucagon-like peptide 1 agonist used in the treatment of diabetes mellitus. It enhances the insulin response to hyperglycemia. Because of a poor insulin response, adult camelids are susceptible to hyperglycemia from stress, glucose administration, or energy metabolism disorders. Insulin often is administered to decrease plasma glucose concentration, but this approach has disadvantages such as the risk of hypoglycemia. Noninsulin medications targeting the incretin hormone pathway, such as exenatide, are providing alternate treatment options.
Hypothesis/Objectives: Exenatide will decrease plasma glucose and increase insulin concentrations in alpacas.
Animals: Six healthy adult alpacas.
Methods: After food was withheld for 8 hours, alpacas were given, on subsequent days in a randomly determined order, either 0.2 μg/kg of exenatide or similar volume of isotonic saline SC. Blood samples were collected before and 15, 30, 45, 60, 75, 90, 105, and 120 minutes after treatment. A rapid dextrose (0.5 g/kg) injection was given after the time 60 samples. Plasma glucose and insulin concentrations were measured at each time point.
Results: Alpacas had significantly ( P = < .001–.015) lower plasma glucose and higher insulin concentrations for the hyperglycemic period after receiving exenatide than after saline injections. Colic signs were observed in 5 of 6 alpacas treated with exenatide.
Conclusions and Clinical Importance: Exenatide appeared to increase insulin release and decrease plasma glucose concentrations in hyperglycemic alpacas. These findings are similar to findings in humans and could support therapeutic usage of exenatide in alpacas. However, induction of colic may limit practical application.