Figure 1.
Figure 1.

Representative electrospray mass spectrum of the norditerpenoid alkaloids in the tall larkspur (Delphinium barbeyi) population used in this study. The major ions detected include deltaline (MH+ m/z = 508) and methyllycaconitine (MLA; MH+ m/z = 683). MSAL = N-(methylsuccinimido) anthranoyllycoctonine.

 


Figure 2.
Figure 2.

A computer model of serum methyllycaconitine (MLA) concentrations after a multiple-dose regimen of tall larkspur given via oral gavage at 8 mg alkaloid/kg BW. The single-dose data (●) were the data used to calculate the kinetic parameters (n = 12; Green et al., 2011) used for the computer modeling. The computer model was generated using PKfit (Lee et al., 2005), a package designed for the software program R (http://www.r-project.org/about.html).

 


Figure 3.
Figure 3.

Computer modeling of serum methyllycaconitine (MLA) concentrations for various doses of a multiple-dosing regimen of tall larkspur. Lines represent the computer simulated data, and symbols represent the actual data points (n = 4 per group).

 


Figure 4.
Figure 4.

Estimation of a toxic threshold for serum methyllycaconitine (MLA) concentrations in clinically poisoned cattle. Lines represent the computer simulated data, and symbols represent the actual data points (n = 4 per group). The horizontal line represents a possible toxic threshold of serum MLA for a clinically poisoned animal, which was set at 355 ng/mL.

 


Figure 5.
Figure 5.

A comparison of serum methyllycaconitine (MLA) concentrations using a multiple-dosing regimen of tall larkspur with 12- and 8-h intervals. The data represent computer simulations of the various dosing regimens.