Table 2. Mean (± SEM) plasma concentrations of cortisol, muscle protein levels of IR-β, IGF-1R, PKCζ and calpastatin, and muscle glycogen content in fetuses infused i.v. with either saline or cortisol for 5 days, and in fetuses whose mothers were injected i.m. with either saline or dexamethasone.

	Fetal administration		Maternal administration
	Saline	Cortisol	Saline	Dexamethasone
Gestational age (days)	130±0	131±0.2	127±0	127±0
Plasma cortisol (ng.ml−1)	14.1±2.0	91.2±20.9*	16.1±2.8	8.6±0.7*
Muscle IR-β (au)	1.00±0.20	1.11±0.10	1.00±0.06	0.88±0.06
Muscle IGF-1R (au)	1.00±0.21	1.06±0.13	1.00±0.16	0.84±0.13
Muscle PKCζ (au)	1.00±0.09	0.86±0.06	1.00±0.03	1.02±0.04
Muscle calpastatin (au)	1.00±0.09	0.83±0.10	1.00±0.04	1.07±0.13
Muscle glycogen (mg.g tissue−1)	46.27±3.72	48.38±2.21	48.70±1.95	50.51±3.14

^*, significantly different from the respective saline control group, Student’s t-test, p<0.05. IR-β, insulin receptor β-subunit; IGF-1R, insulin-like growth factor-1 receptor; PKCζ, protein kinase C ζ; au, arbitrary units.