Comparative effects of risedronate, atorvastatin, estrogen and SERMs on bone mass and strength in ovariectomized rats.
OBJECTIVE
The aim of this study was to investigate bone protective effects of risedronate, atorvastatin, raloxifene and clomiphene citrate in ovariectomized rats.


METHODS
Our study was conducted on 63 rats at Experimental Research Center of Celal Bayar University. Six-month-old rats were divided into seven groups. There were five drug administered ovariectomized groups, one ovariectomized control group without drug administration and one non-ovariectomized control group without drug administration. Eight weeks postovariectomy, rats were treated with the bisphosphonate risedronate sodium, the statin atorvastatin, the estrogen 17beta-estradiol and the selective estrogen receptor modulators (SERMs) raloxifene hydrochloride and clomiphene citrate by gavage daily for 8 weeks. At the end of the study, rats were killed under anesthesia. For densitometric evaluation, left femurs and tibiae were removed. Left femurs were also used to measure bone volume. Right femurs were used for three-point bending test.


RESULTS
Compared to ovariectomized group, femur cortex volume increased significantly in non-ovariectomized group (p=0.016). Compared to non-ovariectomized group, distal femoral metaphyseal and femur midshaft bone mineral density values were significantly lower in ovariectomized group (p=0.047). In ovariectomy+atorvastatin group, whole femur and femur midshaft bone mineral density and three-point bending test maximal load values were significantly higher than ovariectomized group (p=0.049, 0.05, and 0.018). When compared to the ovariectomized group, no significant difference was found with respect to femoral maximum load values in groups treated with risedronate, estrogen, raloxifene and clomiphene (p=0.602, 0.602, 0.75, and 0.927). In ovariectomy+risedronate group, femur midshaft bone mineral density values were significantly higher than the values in ovariectomized group (p=0.023). When compared to ovariectomized group, no significant difference was found with respect to femur midshaft bone mineral density values in groups treated with estrogen, raloxifene and clomiphene (p=0.306, 0.808, and 0.095).


CONCLUSIONS
While risedronate sodium prevented the decrease in bone mineral density in ovariectomized rats, atorvastatin maintained mechanical characteristics of bone and also prevented the decrease in bone mineral density as risedronate sodium.
Uyar
Yildiz
Y
Department of Obstetrics and Gynecology, Faculty of Medicine, Celal Bayar University, Manisa, Turkey. yildizuyar@ttmail.com
Baytur
Yesim
Y
Inceboz
Umit
U
Demir
Bilge Cetinkaya
BC
Gumuser
Gul
G
Ozbilgin
Kemal
K
D000818:Animals; D000924:Anticholesteremic Agents / Q000494:pharmacology*; D000069059:Atorvastatin; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D002996:Clomiphene / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D012968:Etidronic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D005269:Femur / Q000187:drug effects; D006538:Heptanoic Acids / Q000494:pharmacology*; D010024:Osteoporosis / Q000517:prevention & control*; D010052:Ovariectomy; D011758:Pyrroles / Q000494:pharmacology*; D020849:Raloxifene Hydrochloride / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D000068296:Risedronic Acid; D020845:Selective Estrogen Receptor Modulators / Q000494:pharmacology*; D013977:Tibia / Q000187:drug effects
D000924:Anticholesteremic Agents; D050071:Bone Density Conservation Agents; D004967:Estrogens; D006538:Heptanoic Acids; D011758:Pyrroles; D020845:Selective Estrogen Receptor Modulators; D002996:Clomiphene; D020849:Raloxifene Hydrochloride; D000069059:Atorvastatin; D000068296:Risedronic Acid; D012968:Etidronic Acid