Table 2.

Mechanical Properties

	Ctl HCD	GHS HCD	Ctl LCD	GHS LCD
Humeri (cortical bone)
Failure stress (MPa)	202 ± 5	193 ± 9	118 ± 10*	148 ± 8†‡
Failure strain	0.064 ± 0.003	0.044 ± 0.002*	0.099 ± 0.004*	0.065 ± 0.004†‡
Modulus (MPa)	3253 ± 165	4633 ± 461*	1164 ± 96*	2278 ± 215†‡
Toughness (J/mm2)	7.8 ± 0.4	4.6 ± 0.3*	8.5 ± 0.9	6.2 ± 0.3†‡
Fifth lumbar vertebrae (trabecular bone)
Failure stress (MPa)	19.8 ± 1.7	16.3 ± 1.5	7.5 ± 0.7*	5.8 ± 0.7†
Failure strain	0.078 ± 0.007	0.070 ± 0.006	0.093 ± 0.018	0.059 ± 0.009‡
Modulus (MPa)	251 ± 6	238 ± 24	88 ± 11*	89 ± 6†
Toughness (J/mm2)	0.87 ± 0.12	0.62 ± 0.9	0.37 ± 0.7*	0.23 ± 0.6†

Data are mean ± SE; n = 8 all groups.

* Different from Ctl eating HCD, p < 0.001.

^† Different from GHS eating HCD, p < 0.001.

^‡ Different from Ctl eating LCD, p < 0.001.

Ctl, control rats; GHS, genetic hypercalciuric stone forming rats; HCD, high Ca diet,1.2% Ca; LCD, low Ca diet, 0.02% Ca.