Bone Abstracts

Evaluation of time-related changes of serum biochemical bone metabolism markers was performed in male pigs. Control group (n=7) received saline. NanoCa group (n=7) received nanopartical calcium per os (Ace Nano Calcium, NanoTechWorld, Korea). Dex group (n=7) received dexamethasone (1 mg/kg/48 hr i.m.). NanoCa/Dex group (n=6) received simultaneously nanopartical calcium and dexamethasone the same as the groups NanoCa and Dex. Nanopartical calcium was administered at two different dosages; 250 mg/pig/day (1-120 day) and 500 mg/pig/day (121-180 day). Dexamethasone and nanopartical calcium were administered throughout 6 months to accelerate bone metabolism. Blood was collected from 28- and 180-day-old piglets. Bone-specific alkaline phosphatase (BAP) concentration was determined using an immunoenzymometric assay (Ostease^®BAP, IDS Ltd., UK). Osteocalcin (OC) concentration was assessed using MicroVue Human Osteocalcin EIA Kit (QUIDEL, USA). C-terminal telopeptide of type-I collagen (CTX-I) was evaluated using Serum CrossLaps^® ELISA (IDS Ltd., UK). Insulin-like growth factor-1 (IGF-1) was determined using OCTEIA IGF-1 (IDS Ltd., UK). Parathormone (PTH) was determined using Porcine Intact PTH Elisa Kit (Immunotopics Inc., U.S.A). Statistical comparison was performed using Student t-test and P<0.05 was statistically significant. Serum concentrations of BAP, OC and PTH were lowered by 54, 20 and 16% in 180-day-old pigs when compared to 28-day-old group (P≤0.001). Serum concentrations of CTX-I and IGF-1 were increased by 181 and 60% in 180-day-old pigs when compared to 28-day-old group (P<0.001). In conclusion, this study has shown higher levels of bone formation markers such as BAP and OC in younger pigs confirming intensive skeletal formation in rapidly growing pigs. Bone resorption marker (CTX-I) level in serum was nearly three-fold higher in the older group of pigs when compared to the younger group, confirming higher resorption rate of bone tissue in animals with significantly higher skeletal bone mass. IGF-1 concentration was elevated in the older group while an opposite results were obtained for PTH.