TABLE 2.

Kinetic parameters of insulin stimulated estrone sulfate and adefovir transport in rat kidney basolateral membrane vesicles

Rat cortical slices were preincubated for 30 min with or without 30 μg/ml insulin and membrane vesicles were then isolated as described under “Experimental Procedures.” Uptake of 1–15 μm [³H]ES or 3–90 μm [³H]ADF was measured for 30 s (initial rate per preliminary experiments. Data not shown). The apparent K_m of ES and ADF were not significantly altered by insulin treatment, but the V_max were significantly increased.

	Estrone sulfate		Adefovir
	Km	Vmax	Km	Vmax
	μm	pmol/30 s/mg protein	μm	pmol/30 s/mg protein
Control	6.4 ± 3.2	90.8 ± 29.3	27.7 ± 6.4	55.5 ± 11.2
Insulin	4.7 ± 1.9	217.6 ± 58.3a	33.2 ± 8.2	140.3 ± 20.8a

^aThe data are mean ± S.E. for three replicate experiments in kidneys from different animals.