Serum elimination profiles of methyllycaconitine and deltaline in cattle following oral administration of larkspur (Delphinium barbeyi).
OBJECTIVE
To describe the simple elimination kinetics of methyllycaconitine (MLA) and deltaline and evaluate the heart rate response in cattle following oral administration of larkspur.


METHODS
5 healthy Angus steers that were habituated to metabolism crates.


METHODS
Tall larkspur (Delphinium barbeyi) in the early flowering stage was collected, dried, and ground. Each steer received a single dose of larkspur that was equivalent to 10.4 mg of MLA/kg and 11.0 mg of deltaline/kg via oral administration. Steers were housed in metabolism crates during a 96-hour period following larkspur administration; heart rate was monitored continuously, and blood samples were collected periodically for analysis of serum MLA and deltaline concentrations as well as assessment of pharmacokinetic parameters.


RESULTS
No overt clinical signs of poisoning developed in any steer during the experiment. Mean +/- SE heart rate reached a maximum of 79.0 +/- 5.0 beats/min at 17 hours after larkspur administration. Serum MLA concentration was correlated directly with heart rate. Mean times to maximal serum concentration of MLA and deltaline were 8.8 +/- 1.2 hours and 5.0 +/- 0.6 hours, respectively. Mean elimination half-life values for MLA and deltaline were 20.5 +/- 4.1 hours and 8.2 +/- 0.6 hours, respectively.


CONCLUSIONS
Following larkspur administration in 5 healthy steers, maximum serum concentrations of MLA and deltaline were detected within 10 hours, and changes in serum MLA concentration and heart rate were correlated. Results indicated that cattle that have consumed larkspur will eliminate 99% of MLA and deltaline from serum within 144 hours.
Green
Benedict T
BT
USDA Agricultural Research Service, Poisonous Plant Research Laboratory, 1150 E 1400 N, Logan, UT 84341, USA.
Welch
Kevin D
KD
Gardner
Dale R
DR
Stegelmeier
Bryan L
BL
Davis
T Zane
TZ
Cook
Daniel
D
Lee
Stephen T
ST
Pfister
James A
JA
Panter
Kip E
KE
D000157:Aconitine / Q000031:analogs & derivatives* / Q000378:metabolism; D000470:Alkaloids / Q000097:blood / Q000378:metabolism; D000818:Animals; D019540:Area Under Curve; D002417:Cattle; D002418:Cattle Diseases / Q000139:chemically induced*; D031882:Delphinium; D004224:Diterpenes / Q000378:metabolism*; D006207:Half-Life; D008297:Male; D010939:Plant Poisoning; D010947:Plants, Toxic
D000470:Alkaloids; D004224:Diterpenes; C528313:deltaline; C054634:methyllycaconitine; D000157:Aconitine