Table 1

Comparison of continuously infused rGH and hGH on gender-dependent expression of hepatic CYPs in male rats

	Male		Female Vehicle
		1.25 μg/kg b.wt./h		10 μg/kg b.wt./h
	Vehicle	rGH		hGH	rGH	hGH
CYP2C11
Protein	100 ± 6	51 ± 9	82 ± 5^1-a	10 ± 3	30 ± 6^1-a	N.D.
T 2αOH	100 ± 9^1-b	36 ± 7	62 ± 11^1-a	12 ± 5	18 ± 2	4 ± 1
CYP3A2
Protein	100 ± 4	32 ± 5	56 ± 8^1-a	13 ± 2	17 ± 4	N.D.
T 6βOH	100 ± 7	27 ± 6	54 ± 2^1-a	11 ± 2	13 ± 3	6 ± 1
CYP2C12
Protein	N.D.	50 ± 9	23 ± 3^1-a	70 ± 9	44 ± 6^1-a	100 ± 7
T 5αred	5 ± 1	56 ± 10	33 ± 1^1-a	83 ± 8	67 ± 3^1-a	100 ± 11
CYP2C7
Protein	28 ± 4	54 ± 8	32 ± 4^1-a	81 ± 6	64 ± 5^1-a	100 ± 5

Osmotic mini pumps implanted i.p. in male and female rats were calibrated to deliver either 1.25 or 10 μg/kg b.wt./hr of either rGH or hGH or an equivalent volume of vehicle for 7 continuous days. Relative CYP protein levels determined by laser densitometry of actual Western enhanced chemiluminescence autoradiographs and microsomal specific CYP-dependent or associated testosterone 2α-hydroxylase (T 2αOH), testosterone 6β-hydroxylase (T 6βOH), and testosterone 5α-reductase (T 5αred) levels of at least 4 different livers for each treatment group.

Values are presented as mean ± S.D.

N.D., not detectable.
↵1-a P < 0.01 compared with same-dose rGH-treated rats.
↵1-b Control enzyme values (i.e., 100%) were 2.73 ± 0.25, 1.26 ± 0.09, and 5.1 ± 0.56 nmol/min/mg of protein for T 2αOH, T 6βOH, and T 5αred, respectively.