Doping dose of salbutamol and exercise training: impact on the skeleton of ovariectomized rats

• Published in: Journal of applied physiology (1985) 2007-08, Vol.103 (2), p.524-533
• Main Authors: Bonnet, N, Laroche, N, Beaupied, H, Vico, L, Dolleans, E, Benhamou, C. L, Courteix, D
• Format: Article
• Language: English
• Subjects: Adrenergic beta-Agonists - pharmacology; Albuterol - pharmacology; Animals; Biological and medical sciences; Biomechanical Phenomena; Body Mass Index; Bone and Bones - drug effects; Bone and Bones - pathology; Bone and Bones - physiopathology; Bone Density - drug effects; Bone Density - physiology; Bone Diseases, Metabolic - etiology; Bone Diseases, Metabolic - physiopathology; Bones; Disease Models, Animal; Doping in Sports; Dose-Response Relationship, Drug; Drugs; Estrogens; Estrogens - physiology; Exercise; Female; Fundamental and applied biological sciences. Psychology; Ovariectomy; Ovary - physiology; Ovary - surgery; Physical Conditioning, Animal - physiology; Rats; Rats, Wistar; Rodents; Skeletal system; Studies
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.01319.2006

1 INSERM U658, Caracterisation du Tissu Osseux par Imagerie, Techniques et Applications and Architecture du Tissu Osseux—Exercise Physiology, School of Sports Sciences and Physical Education, Orleans Regional Hospital and University of Orleans, Orleans; and 2 INSERM E366, Laboratoire de Biologie du Tissu Osseux, University of St. Etienne, St. Etienne, France Submitted 21 November 2006 ; accepted in final form 26 April 2007 Previous studies in healthy rats have demonstrated a deleterious bone impact of -agonist treatment. The purpose of this study was to examine the trabecular and cortical effects of 2 -agonists at doping dose on treadmill exercising rats with estrogen deficiency. Adult female rats were ovariectomized (OVX; n = 44) or sham operated ( n = 12). Then, OVX rats received a subcutaneous injection of salbutamol (SAB) or vehicle with (EXE) or without treadmill exercise for 10 wk. Bone mineral density (BMD) was analyzed by densitometry. Microcomputed tomography and histomorphometric analysis were performed to study trabecular bone structure and bone cell activities. After 10 wk, SAB rats presented a much more marked decrease of BMD and trabecular parameters. Exercise did not change the high level of bone resorption in OVX EXE SAB compared with OVX SAB group (both on COOH-terminal collagen cross-links and osteoclast number). These results confirm the deleterious effect of 2 -agonists on bone quantity (femoral BMD gain: OVX EXE, +6.8%, vs. OVX EXE SAB, –1.8%; P < 0.01) and quality (–8.0% of femoral trabecular thickness in OVX EXE SAB vs. OVX EXE), indicating that SAB suppresses the effect of EXE in OVX rats. Furthermore, we notice that the slight beneficial effect of exercise was mainly localized in the tibia. These findings indicate the presence of a bone alteration threshold below which there is no more alteration in structural bone quantity and quality. The negative effects of SAB on bone observed in this study in trained rats may indicate potential complications in doping female athletes with exercise-induced amenorrhea. -agonist; estrogen deficiency Address for reprint requests and other correspondence: N. Bonnet, Inserm U658, CHR Orleans, 1, rue porte Madeleine, 45000 Orleans, France (e-mail: nicolas.bonnet15{at}wanadoo.fr )