Report and Opinion, 2009; 1(6) Ahmed and Hamza Potential role of Arginine http://www.sciencepub.net/report reportopinion@gmail.com 24 Potential Role of Arginine, Glutamine and Taurine in Ameliorating Osteoporotic Biomarkers in Ovariectomized Rats Hanaa, H.Ahmed 1 and Amal H. Hamza 2 1. Hormones Department, National Research Center, Dokki, Cairo, Egypt. 2. Biochemistry and Nutrition Department, Faculty of Women, Ain Shams University, Cairo, Egypt. amal_hamza@hotmail.com Abstract The main purpose of the present study was to evaluate the role of some amino acids namely L-arginine, L- glutamine and taurine in the management of osteoporosis in ovariectomized (OVX) rats. The current study included six groups of female rats which were classified as gonad intact control group and five ovariectomized groups: one untreated group served as ovariectomized control group another ovariectomized group orally administered with 10% lactose, three ovariectomized groups orally administered with each amino acid dissolved in 10% lactose. The treatment was started after 3 months of ovariectomy and continued for other 3 months. Serum parathyroid hormone (PTH), 1, 25 dihydroxyvitamine D 3 levels were determined. Insulin like growth factor-1 (IGF-1) and transforming growth factor-β (TGF-β) levels were also estimated. Bone mineral density (BMD) and bone mineral content (BMC) of right femur bone of each rat were measured using DEXA technique. Also, histological investigation of the bone sections of left femur of each rat was carried out. The obtained data revealed that ovariectomy decreased serum 1, 25 (OH) 2 D 3 , IGF-1 and TGF-β levels whereas, it increased serum PTH level. DEXA results revealed that ovariectomy decreased BMD and BMC of the proximal, distal and mid areas of rat femur bone. These results were well documented by bone histological examination. The selected amino acids could improve all the studied bone biochemical markers significantly. DEXA results also showed that treatment with these amino acids could increase both BMD and BMC of rat femur bone in most areas. The photomicrographs of femur bone sections of rats treated with the selected amino acids supported the present improvement in bone biomarkers. In conclusion, each of the selected amino acids exhibited antiosteoporotic effects due to the anabolic and/or antiresorptive activity. These encouraging results provide new concepts for the development of effective opportunities in the treatment of primary osteoporosis. “[Report and Opinion. 2009;1(6):24-35].(ISSN:1553-9873)”. Key words: Osteoporosis, L-arginine, L-glutamine, taurine, lactose, bone biomarkers, bone mineralization. Introduction Osteoporosis is a global health problem that will take an increasing significance as people live longer and the world’s population continues to increase in number, thus the management of osteoporosis and its complications is an socioeconomic priority (Kevin, 2007) Osteoporosis is defined as decreased bone strength and increased susceptibility to fractures (Preisinger , 2009). It is also defined as progressive systemic skeletal disease characterized by low bone mass with a consequent increase in bone fragility and susceptibility to fracture. (Katherine et al., 2007). So, there is an urgent need to develop and implement alternative nutritional approaches and policies for treatment of osteoporosis (Kevin, 2007). This idea comes from the fact that protein under nutrition is known to play an important role in the pathogenesis of osteoporotic fracture. The mechanisms underlying the bone loss in protein under nutrition appeared to be related to an uncoupling between increased bone resorption and bone formation. This was associated with decreased plasma insulin-like growth factor-1 (IGF-1) level, with anoestrus and decreased muscle mass. Nutritional intervention with amino acid supplements can increase bone mineral mass, bone strength and muscle mass in osteoporotic subjects (Ammann et al., 2000). Amino acids are the building blocks of protein. Essential amino acids (EAA) can Modulate the growth and the differentiation of osteoblasts cultured in vivo, confirming the relationship between osteoporotic hip fracture and inadequate protein intake. Amino acids have mainly enhanced cell growth and alkaline phosphatase activity, and, to a lower degree, collagen synthesis (Conconi et al., 2001). Amino acids supplement increased bone mineral mass and strength in ovariectomized protein-deprived rats. This was associated with stimulated bone formation and reduced bone resorption, with an increment of plasma isulin-like growth factor (IGF-1) and limb muscle mass weight (Ammann et al., 2000). L-arginine represents a key building block to repair damage tissue and bone. Athletes have also