Table 2.

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 bone mineralization in nonovariectomized and ovariectomized rats

Parameter/group		Nonovariectomized (NOVX) rats				Ovariectomized (OVX) rats
		Control	Morphine	Buprenorphine	Naloxone	Control	Morphine	Buprenorphine	Naloxone
Bone mineral mass/bone mass ratio	Femur	0.440 ± 0.016	0.453 ± 0.014*	0.457 ± 0.013*	0.459 ± 0.012**	0.435 ± 0.011	0.442 ± 0.011	0.442 ± 0.009	0.435 ± 0.011
	Tibia	0.443 ± 0.012	0.451 ± 0.006	0.451 ± 0.011	0.442 ± 0.013	0.436 ± 0.013	0.445 ± 0.009#	0.443 ± 0.008#	0.432 ± 0.007
	L-4 vertebra	0.423 ± 0.017	0.429 ± 0.024	0.431 ± 0.012	0.435 ± 0.010	0.409 ± 0.011^	0.407 ± 0.035	0.417 ± 0.022#	0.409 ± 0.027
Calcium content (g/g of bone mineral)	Femur	0.361 ± 0.011	0.360 ± 0.010	0.361 ± 0.013	0.366 ± 0.012	0.360 ± 0.034	0.362 ± 0.013	0.363 ± 0.010	0.367 ± 0.011
	Tibia	0.364 ± 0.011	0.373 ± 0.014	0.369 ± 0.009	0.371 ± 0.007	0.366 ± 0.007	0.370 ± 0.007	0.362 ± 0.007	0.363 ± 0.013
	L-4 vertebra	0.360 ± 0.010	0.369 ± 0.006	0.365 ± 0.006	0.362 ± 0.011	0.361 ± 0.013	0.366 ± 0.005	0.367 ± 0.007	0.362 ± 0.010
Phosphorus content (g/g of bone mineral)	Femur	0.161 ± 0.006	0.159 ± 0.005	0.160 ± 0.003	0.161 ± 0.005	0.165 ± 0.009	0.162 ± 0.006	0.162 ± 0.003	0.163 ± 0.005
	Tibia	0.161 ± 0.006	0.160 ± 0.003	0.160 ± 0.003	0.162 ± 0.003	0.163 ± 0.003	0.161 ± 0.001	0.160 ± 0.004	0.161 ± 0.003
	L-4 vertebra	0.159 ± 0.005	0.161 ± 0.003	0.160 ± 0.004	0.162 ± 0.003	0.158 ± 0.006	0.161 ± 0.002	0.161 ± 0.003	0.160 ± 0.007

Results are presented as means ± SD

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