TABLE 2

Compartmental pharmacokinetic parameter estimates for DA following i.v. (0.5 μg/kg) and s.c. (2 μg/kg) administration in sheep

Models were simultaneously fit to the mean data for n = 4 animals in each group; the S.D. reflects the confidence in the parameter estimates.

Parameter
i.v. Bolus
Interdigital
Abdomen
Shoulder
s.c. Control (noncannulated)
    Vc (ml/kg)a 44.8 ± 2.5 44.8 ± 2.5 44.8 ± 2.5 44.8 ± 2.5
    k12 (/h)a 0.206 ± 0.083 0.206 ± 0.083 0.206 ± 0.083 0.206 ± 0.083
    k21 (/h)a 0.290 ± 0.097 0.290 ± 0.097 0.290 ± 0.097 0.290 ± 0.097
    k10 (/h)a 0.0493 ± 0.0030 0.0493 ± 0.0030 0.0493 ± 0.0030 0.0493 ± 0.0030
    Tlag_lymph (h) 0.19 ± 0.11 53.6 ± 13.6
    Tlag_blood (h)
    Fabs (%) 92 ± 1 83 ± 9 99 ± 5
    ka (/h) 0.151 ± 0.003 0.0240 ± 0.0021 0.0815 ± 0.0101
s.c. Central lymph-cannulated
    klymph1 (/h) 0.204 ± 0.008 0.0456 ± 0.0084 b
    klymph2 (/h) 0.0211 ± 0.0005 b
    kblood1 (/h) 0.00481 ± 0.00060 0.00281 ± 0.00021 b
    kblood2 (/h) 0.0133 ± 0.0020 b
    Tlag_lymph (h) 0.38 ± 0.05 100 ± 15 b
    Tlag_blood (h) 102 ± 12 b
    Flymph (%) 90 ± 1 67 ± 9 b
    Fblood (%)
2.0 ± 0.3
16 ± 2
b

  • ↵ a The parameters k12, k21, k10, and Vc were constrained to be equal in each group. The rate constants klymph and kblood were constrained to be equal in the noncannulated and cannulated s.c. groups.

  • ↵ b Lymph-cannulated data for the shoulder injection site were not fit to a model.