Table 3.

Effects of morphine hydrochloride (20 mg/kg s.c.), buprenorphine hydrochloride (0.05 mg of buprenorphine/kg s.c.), and naloxone hydrochloride dihydrate (2 mg/kg s.c.), administered for 4 weeks, on mechanical properties of the tibial metaphysis (Young’s modulus and the parameters for the fracture point) and on mechanical properties of the femoral diaphysis and femoral neck in nonovariectomized and ovariectomized rats

Parameter/group		Nonovariectomized (NOVX) rats				Ovariectomized (OVX) rats
		Control	Morphine	Buprenorphine	Naloxone	Control	Morphine	Buprenorphine	Naloxone
Tibia	Young’s modulus (MPa)	1997 ± 606	2026 ± 780	1953 ± 637	1818 ± 507	1209 ± 308^^^	1979 ± 869##	1370 ± 495	1402 ± 279
	Fracture load (N)	71.54 ± 17.01	80.64 ± 8.92	78.76 ± 23.62	79.33 ± 17.49	39.07 ± 9.59^^^	46.85 ± 9.31#	51.53 ± 8.86##	48.58 ± 9.68#
	Displacement for fracture load (mm)	1.318 ± 0.365	1.322 ± 0.412	1.408 ± 0.341	1.343 ± 0.381	1.687 ± 0.230^^	1.311 ± 0.247###	1.512 ± 0.233	1.390 ± 0.212#
	Energy for fracture load (J)	0.075 ± 0.024	0.084 ± 0.019	0.084 ± 0.018	0.079 ± 0.022	0.067 ± 0.009	0.065 ± 0.017	0.069 ± 0.006	0.057 ± 0.012#
	Stress for fracture load (MPa)	53.27 ± 24.26	56.89 ± 13.34	55.72 ± 20.11	53.03 ± 14.94	25.97 ± 6.89^^^	33.45 ± 9.84	34.97 ± 6.48##	33.19 ± 8.73
Femur	Diaphysis–Young’s modulus (MPa)	11,460 ± 2881	10,922 ± 1949	10,563 ± 1178	10,476 ± 1768	9672 ± 2222	9647 ± 2313	9945 ± 1838	10,257 ± 1304
	Diaphysis–maximum load (N)	101.86 ± 8.69	100.25 ± 11.55	102.50 ± 10.36	101.90 ± 13.70	100.68 ± 12.95	95.53 ± 6.24	101.85 ± 14.15	104.87 ± 10.79
	Neck–maximum load (N)	79.73 ± 5.88	82.62 ± 9.91	78.47 ± 12.63	73.75 ± 20.88	82.72 ± 14.19	83.37 ± 11.38	82.58 ± 7.07	74.70 ± 7.36

Results are presented as means ± SD

^^p < 0.01, ^^^p < 0.001, significant differences between the NOVX and OVX controls; ^# p < 0.05, ^## p < 0.01, ^### p < 0.001, significantly different from the OVX control rats