Table 1

Derived IC50 and Ki values for amantadine inhibition of energy-dependent uptake of TEA by isolated rat renal cortical proximal and distal tubules compared to apparentKm values calculated for amantadine transport under the same conditions

TubuleBufferIC50Ki1-aKmAKmA/Ki
ProximalKHS56  ± 1240  ± 9190  ± 111-b 4.8
ProximalCT52  ± 1141  ± 8412  ± 231-b 1-c 10.0
DistalKHS82  ± 1460  ± 11102  ± 111-b 1.7
DistalCT48  ± 838  ± 7245  ± 341-b 1-c 6.4

Concentrations are expressed in μM ± S.E.M. of four to seven experiments.

  • 1-a Ki values were similar in all four groups (two-way ANOVA with tubule and buffer as grouping factors).

  • 1-b p < .01, Km vs.Ki within the same tubule and buffer group.

  • 1-c p < .01 vs. Km in KHS buffer within the same tubule group.