engleski

Genetic variability in new bone formation among inbred mouse strains

There is strong evidence that genetic factors determine the amount of bone in humans and animals.We studied genetic differences in new bone induction by xenogeneic bone matrix in 8 mouse inbred strains: A/J (H-2a), AKR/J (H-2k), BALB/c (H-2d), C3Hf (H-2k), C57BL/6 (H-2b), CBA/J (H-2k), DBA/2 (H-2d) and RFM (H-2k).Antigen-extracted autolyzed rat bone matrix (bone matrix gelatin) was implanted under thigh muscle fascia of ten 12-week-old mice for each strain. New bone formation was morphologically assessed 4 weeks after implantation. Mouse strains could be classified into poor and good responders according to their osteoinductive reaction. Bone matrix implants in CBA, A/J and C3H induced only cartilige induction in less than half of the mice, whereas cartilige formation was observed in more than 80% of the implants from AKR, C57BL/6, BALB/c, DBA and RFM. Formation of abundant new bone and functional bone marrow was observed in more than half of the mice from the latter group. The differences in osteoinductive reaction to bone matrix among inbred strains could not be explaned by immunological reaction to rat matrix because there was no segregation of H-2 haplotypes between poor and good responders. Poor responders have a distant common origin from Strong 1921 stock, whereas the other strains have independent origin. Our data differ from the report on the adult bone density in inbred strains showing that C3H mice (poor osteoinductive responder) had the highest and C57BL/6 mice (good responder) had the least femur cortical density.This indicates that adult bone density may not correlate with the regenerative capacity of the bone.

bone formation; mouse; osteoinductive reaction; bone matrix implant; bone density

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