Table 1. Morphological and molecular biological changes during postnatal growth.

	Postnatal weeks
	2 wk	4 wk	8 wk	12 wk
	n = 5	n = 5	n = 5	n = 5
Body weight (g)	32.8 ± 1.1	88.4 ± 2.3	278.4 ± 6.2	419.0 ± 7.6
Plantaris muscle wet weight (mg)	16.2 ± 0.6	71.7 ± 7.3	298.6 ± 17.7	464.5 ± 15.9
Muscle wet weight/body weight (mg/g)	0.99 ± 0.03	1.62 ± 0.14*	2.14 ± 0.10*†	2.21 ± 0.09*†
HGF mRNA	1.00 ± 0.33	0.57 ± 0.13*	0.44 ± 0.25*	0.35 ± 0.09*
MyoD mRNA	1.00 ± 0.14	0.86 ± 0.06	0.59 ± 0.19*	0.73 ± 0.20

Data are expressed as mean ± standard deviation. *p < 0.01, compared with 2 wk. †p < 0.01, compared with 4 wk