Assessment of the effects of exogenous long-acting insulin on glucose tolerance in alpacas.
OBJECTIVE
To evaluate the effects of long-acting insulin on glucose clearance in alpacas.


METHODS
8 adult castrated alpacas.


METHODS
On 2 days, food was withheld from alpacas for 8 hours. Alpacas were randomly allocated to receive an SC injection of long-acting insulin (0.4 U/kg) or saline (0.9% NaCI) solution 1 hour before the first of 3 administrations of glucose (at 60, 480, and 1,200 minutes after treatment) on day 1 and the alternate treatment and procedure on day 2. Plasma glucose concentration was determined before and 15, 45, 120, and 240 minutes after each glucose administration, and fractional turnover rates were calculated. The data were compared between alpacas with and without insulin administration and among the 3 glucose administrations for each day.


RESULTS
Compared with sham-treated alpacas, insulin-treated alpacas had significantly lower blood glucose concentrations from 180 to 600 minutes after treatment; they also had glucose concentrations significantly below baseline values from 120 to 480 minutes, at which time the mean glucose concentration was in the hypoglycemic range. Also, mean fractional turnover of glucose was significantly higher in insulin-treated alpacas from 105 through 300 minutes.


CONCLUSIONS
Compared with known effects of regular insulin in alpacas, the action of long-acting insulin was of slower onset but longer lasting; its administration may induce hypoglycemia, even in alpacas that receive glucose. To maintain the hypoglycemic effect, long-acting insulin may have to be administered more than once daily and blood glucose concentration should be monitored to avoid hypoglycemic complications in alpacas.
Ueda
Jaime
J
Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802, USA.
Cebra
Christopher K
CK
Tornquist
Susan J
SJ
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002161:Camelids, New World / Q000378:metabolism*; D005951:Glucose Tolerance Test / Q000662:veterinary*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D049528:Insulin, Long-Acting / Q000494:pharmacology*; D008297:Male
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D049528:Insulin, Long-Acting