This study was undertaken to determine the osteotropic effect of different doses of lipoic acid (LA) on the mineralization of bone tissue in female Wistar rats with experimental osteopenia induced by bilateral ovariectomy. Fifty-six rats were randomly selected and submitted to either a sham operation (n = 8) or an ovariectomy (n = 48). The ovariectomized rats were randomly placed into two control groups, treated subcutaneously with either physiological saline or 17β-estradiol in the dose of 4 µg/kg body mass per day, and four experimental groups that received LA subcutaneously in the doses of 12.5, 25, 50, and 100 mg/kg body mass per day (n = 8 in each group). After 28 days of experimental treatment, the rats were sacrificed, and body mass, total skeletal density, and body composition were recorded. Blood serum and isolated femora were stored for further analysis. Our results revealed that the osteoprotective effect of LA was dose-dependent and was observed in rats treated with 50 and 100 mg/kg of LA. Moreover, the LA applied to the ovariectomized rats in the dose of 50 mg/kg not only stopped the bone resorption, but stimulated its formation. Key words: rats, bone tissue, osteopenia, ovariectomy, densitometry, pQCT, lipoic acid, estradiol. L'etude a ete entreprise en vue de determiner l'effet osteotropique de differentes doses d'acide lipoique (AL) sur la mineralisation du tissu osseux dans un modele d'osteopenie induite par ovariectomie bilaterale chez la rate Wistar. Cinquantesix rates ont ete selectionnees aleatoirement pour etre soumises a une intervention chirurgicale factice (n = 8) ou a une ovariectomie (n = 48). Les rates ovariectomisees ont ete reparties aleatoirement dans deux groupes temoins auxquels du salin physiologique ou du 17β-estradiol a 4 µg/kg par jour a ete administre par voie sous- cutanee, et dans quatre groupes experimentaux recevant de l'AL par voie sous-cutanee a des doses de 12,5, de 25, de 50 et de 100 mg/kg par jour (n = 8 dans chaque groupe). Apres 28 jours de traitement experimental, les rates ont ete euthanasiees et nous avons enregistre le poids corporel ainsi que la densite et la composition corporelle squelettiques totales. Nous avons entrepose du serum sanguin et des femurs isoles aux fins de futures analyses. Nos resultats ont revele que l'effet osteoprotecteur de l'AL est proportionnel a la dose chez les rates traitees par 50 et 100 mg/kg d'AL. En outre, l'administration d'AL a 50 mg/kg a permis d'interrompre la resorption osseuse et meme de stimuler la formation de tissu osseux chez les rates ovariectomisees. [Traduit par la Redaction] Mots-cles: rats, tissu osseux, osteopenie, ovariectomie, densitometrie, pQCT (tomodensitometrie quantitative pour os peripherique), acide lipoique, estradiol., Introduction Bone loss changes characterizing osteoporosis occur during aging or after gonadectomy. Hypofunction of gonads results not only in an imbalance between resorption and formation of bone tissue, but also [...]