Table 2.

Pituitary Weight and Uterine Diameter of Young, Middle-aged, and Aged Ovariectomised Female Rats

Age	Hormone treatment	Pituitary weight (normalised to body weight)	Uterine diameter (mm)
Young	Vehicle/vehicle	4.75 × 10-5 ± 1.88 × 10-6 (n = 4)	1.36 ± 0.10 (n = 8)
	Oestradiol/vehicle	6.18 × 10-5 ± 2.59 × 10-6 (n = 7)	4.83 ± 0.37 (n = 7)
	Oestradiol/progesterone	6.07 × 10-5 ± 3.87 × 10-6 (n = 7)	8.34 ± 0.73 (n = 7)
Middle-aged	Vehicle/vehicle	4.96 × 10-5 ± 2.70 × 10-6 (n = 7)	2.13 ± 0.22 (n = 8)
	Oestradiol/vehicle	5.58 × 10-5 ± 3.54 × 10-6 (n = 4)	3.86 ± 0.99 (n = 8)
	Oestradiol/progesterone	6.80 × 10-5 ± 3.67 × 10-6 (n = 4)	4.91 ± 0.41 (n = 8)
Aged	Vehicle/vehicle	5.81 × 10-5 ± 1.26 × 10-6 (n = 5)	2.39 ± 0.38 (n = 7)
	Oestradiol/vehicle	7.93 × 10-5 ± 2.28 × 10-6 (n = 4)	4.60 ± 0.25 (n = 2)
	Oestradiol/progesterone	6.09 × 10-5 ± 1.08 × 10-6 (n = 4)	4.10 ± 0.39 (n = 8)

Pituitary weights and uterine diameter, the latter an index of the uterotrophic effect of oestradiol, were measured in post-mortem rats following perfusion. Pituitary weights did not vary significantly with age, but had a trend for an effect of hormone treatment (P = 0.051). In general, pituitaries were smaller in the vehicle/vehicle groups compared to the oestradiol/vehicle or oestradiol/progesterone groups. Uterine diameter measurements showed no age-associated differences, but there was a main effect of hormone treatment (P < 0.001). Specifically, uterine diameter was larger in oestradiol/vehicle and oestradiol/progesterone than in vehicle/vehicle rats. Data are the mean ± SEM.