Bone Abstracts

The aim of the study was to evaluate time-related changes in serum concentration of bone tissue metabolism markers in Polish Large White male pigs. At birth, the piglets were divided into four groups. The first control group (n=7) received physiological saline i.m. (placebo). The second group (NanoCa group; n=7) were administered p.o. with nanopartical calcium (Ace Nano Calcium, NanoTechWorld, Pohang, Korea). The third group (Dex group; n=7) received dexamethasone (dexamethasone 0.2% solution; Rapidexon, Novartis, The Netherlands) in i.m. injections at a dose of 1 mg/kg per 48 h. The fourth group (NanoCa/Dex group; n=6) received simultaneously p.o. nanopartical calcium and dexamethasone in the same dosage as the second and third group. Nanopartical calcium was administered p.o. in the second and fourth groups at two different dosages – namely 250 mg/pig per day (since birth up to 4 months of life) and 500 mg/pig per day (up to 6 months). Administration with dexamethasone and nanopartical calcium was applied in this study to accelerate bone tissue metabolism of the experimental animals. Blood samples for serum were collected from piglets at the age of 28 and 180 days of life. Bone-specific alkaline phosphatase (BAP) concentration in serum of pigs was determined using an immunoenzymometric assay (Ostease BAP, Immunodiagnostic Systems Ltd, Boldon, Tyne & Wear, UK). Osteocalcin (OC) concentration of was assessed using MicroVue Human Osteocalcin EIA Kit (QUIDEL, San Diego, CA, U.S.A). C-terminal telopeptide of type-I collagen (CTX-I) was evaluated using Serum CrossLaps ELISA (IDS Ltd, UK). IGF1 was determined immunoenzymometric assay (OCTEIA IGF1, IDS Ltd, UK). Concentration of parathormone (PTH) was evaluated using Porcine Intact PTH Elisa Kit (Immunotopics, Inc., San Clemente, CA, U.S.A). Statistical comparison of the differences between age-differentiated groups was performed using student t-test for dependent variables and P<0.05 was considered as statistically significant. Serum concentrations of BAP, OC and PTH were significantly 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 IGF1 were significantly increased by 181 and 60% in 180-day-old pigs when compared to 28-day-old group of animals (P<0.001). In conclusion, this study has shown higher leveles 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 threefold higher in the older group of pigs when compared to the group at the age of 28 days of life, confirming higher resorption rate of bone tissue in animals with significantly higher bone mass of the skeleton. IGF1 concentration was significantly elevated in the older group of pigs while an opposite results were stated in case of PTH evaluation.