Assessment of the effects of epinephrine and insulin on plasma and serum biochemical variables in llamas and alpacas.
OBJECTIVE
To describe the metabolic effects of epinephrine administration in New World camelids and investigate whether these effects are influenced by administration of insulin.


METHODS
6 llamas and 8 alpacas (all adult castrated males).


METHODS
Prior to each experiment, food was withheld from camelids for 8 hours. On each of 2 consecutive days, alpacas were administered epinephrine (10 mg/kg, IM; time 0); alpacas were randomly assigned to receive regular insulin (0.2 U/kg, IV) immediately after epinephrine administration on one of those days. In llamas, the experiment was performed once after administration of epinephrine only. At 0, 30, 60, 90, 120, 150, 180, 210, and 240 minutes after treatment, blood samples were collected and several serum or plasma biochemical variables were assessed; in addition, plasma samples from llamas were assessed for insulin concentrations. Data were compared between days (alpacas only) and between time points.


RESULTS
Administration of epinephrine induced mobilization of glucose, triglycerides, nonesterified fatty acids, and beta-hydroxybutyrate. A small increase in endogenous insulin concentration was detected in epinephrine-treated llamas, compared with baseline values. Overall, insulin administration decreased, negated, or delayed the epinephrine-associated increases in serum or plasma concentrations of circulating energy substrates, except that it augmented the epinephrine-associated increase in concentration of triglycerides.


CONCLUSIONS
Epinephrine appeared to mobilize energy substrates in camelids and hence may be involved in the pathogenesis of disorders of glucose and fat metabolism. Insulin appeared to antagonize most of these effects, and its administration may have therapeutic value in camelids.
Cebra
Christopher K
CK
Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802, USA.
Tornquist
Susan J
SJ
D020155:3-Hydroxybutyric Acid / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002161:Camelids, New World / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D004734:Energy Metabolism / Q000187:drug effects*; D004809:Ephedrine / Q000494:pharmacology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol; D004809:Ephedrine; D020155:3-Hydroxybutyric Acid