Table 1.

Characteristics of Male F344 × BN Rats

	Age (mo)†
Parameter	8	18	28	Effect of Age‡
Body weight (g)	440 ± 6	534 ± 13*	544 ± 7*	p < .0001
	(n = 10)	(n = 10)	(n = 12)
Carcass weight (g)	347 ± 5	406 ± 10*	413 ± 6*	p < .0001
	(n = 10)	(n = 10)	(n = 12)
Gastrocnemius weight (g)	2.78 ± 0.04	2.74 ± 0.07	2.41 + 0.06*	P < .0001
	(n = 10)	(n = 10)	(n = 12)
Fat pad content	(n = 10)	(n = 10)	(n = 12)
epididymal fat (g)	7.6 ± 0.3	14.3 ± 0.7*	13.7 ± 0.5*	p < .0001
retroperitoneal fat (g)	5.4 ± 0.2	12.2 ± 0.8*	11.8 ± 0.6*	p < .0001
mesenteric fat (g)	3.8 ± 0.2	12.8 ± 1.0*	13.3 ± 0.7*	p < .0001
Visceral fat = EPI + RP + MES	16.9 ± 0.6	39.3 ± 2.4*	38.9 ± 1.7*	p < .0001
% Fat = visceral fat/body wt.	3.8 ± 0.1	7.3 ± 0.3*	7.2 ± 0.3*	p < .0001
Glucose (mmol/L)	6.2 ± 0.1	6.1 ± 0.2	5.9 ± 0.3	NSD
	(n = 10)	(n = 10)	(n = 12)
Insulin (pmol/l)	181 ± 11	269 ± 19*	244 ± 33*	p = .036
	(n = 10)	(n = 10)	(n = 10)
Citrate synthase activity (µmol/min/µg protein)	99.1 ± 2.6	104 ± 2.8	111.1 ± 6.3	NSD
	(n = 9)	(n = 9)	(n = 12)

^†Values are means ± standard error.

^‡Determined by an analysis of variance.

^*Significant difference p < .05 vs 8-mo-old rats.

NSD = no significant difference.