TABLE 3

K_iandK_mvalues for the uptake of cimetidine, ranitidine, and benzylpenicillin by the isolated rat CP

The effect of estrone sulfate, cimetidine, estradiol-17β-glucuronide (E₂ 17βG), PAH, benzylpenicillin, and ranitidine was examined with regard to uptake by the rat isolated CP. The K_i and K_m values were determined by nonlinear regression analysis as described under Materials and Methods. Data are taken from Fig. 7. Each value represents the mean ± S.E. (n = 3-6).

	K_i and K_m values (μM)
	Benzylpenicillin^a	Cimetidine	Ranitidine
Estrone sulfate	22.3	19.5 ± 8.8
Cimetidine	44.4	92.7 ± 46.1^b
E₂ 17βG	33.0	36.3 ± 15.7
PAH	406	281 ± 74
Benzylpenicillin	111^b	140 ± 97
Ranitidine		49.6 ± 15.1	171 ± 57^b

↵ a Parameters cited from Nagata et al. (2002).
↵ b K_m value.