. Author manuscript; available in PMC: 2013 Oct 30.

Published in final edited form as: J Biol Chem. 2007 Jun 5;282(33):10.1074/jbc.M703467200. doi: 10.1074/jbc.M703467200

Table 2.

Calculation of the maximum uptake rate (V_max) of radiolabeled substrates for Oat6 and Oat1.

[³H]-labeled substrate	S ⁽¹⁾, μM	K_i ⁽²⁾, μM		CL ⁽³⁾, μL/oocyte/hr		V_max ⁽⁴⁾, pmol/oocyte/hr
[³H]-labeled substrate	S ⁽¹⁾, μM	Oat6	Oat1	Oat6	Oat1	Oat6	Oat1
ES	0.017	58 ± 10	203 ± 10	0.693 ± 0.135	0.027 ± 0.010	40.0 ± 10.4	5.5 ± 2.1
PAH	0.237	446 ± 98	9.4 ± 1.1	0.010 ± 0.003	0.590 ± 0.040	4.6 ± 1.7	5.7 ± 0.7
Prostaglandin E2	0.005	18.0 ± 7.5	3.4 ± 1.4	0.050 ± 0.007	0.146 ± 0.032	0.90 ± 0.39	0.49 ± 0.23
Ibuprofen	2.0	1.1 ± 0.2	4.7 ± 1.3	0.090 ± 0.050	0.182 ± 0.033	0.28 ± 0.16	1.2 ± 0.3
Ochratoxin A	0.067	49 ± 10	6.2 ± 0.9	0.098 ± 0.008	1.900 ± 0.145	4.8 ± 1.0	12.0 ± 2.0
Methotrexate	0.05	597 ± 79	901 ± 108	ND ⁽⁵⁾	0.043 ± 0.005	ND ⁽⁵⁾	38.3 ± 6.7

⁽¹⁾

Calculated for the 1 μCi/mL content of [³H]-labeled substrates in the incubation media, based on specific activities (see Materials and Methods).

⁽²⁾

Data from Table 1.

⁽³⁾

Calculated as CL = V_transport/S (plotted in Figure 5B).

⁽⁴⁾

Calculated as V_max = CL·(S+K_i) (plotted in Figure 5C).

⁽⁵⁾

Oat6-mediated uptake of methotrexate is not detectable (no difference between Oat6-injected and uninjected oocytes, see Figure 5A).