Latvijas Lauksaimniecības universitātes raksti nr. 18 (313) , 2007 ...

M. Pilmane et al. Investigation of Cow Bone Tissue Structurebut also in wound healing (Borland et al., 2001;Bottcher, Niehrs, 2005). Additionally, Frenz et al.(1994) investigated FGF induction in chondrogenesisand proved its stimulating role in the regulation ofchondrogenesis during otic capsule formation inmouse inner ear in situ.Besides above mentioned, fibroblast growthfactor and bone morphogenetic proteins are importantregulators of mesenchymal, preosteoblast, andosteoblast apoptosis in suture areas (Fromigue etal., 2005). Generally, in the bone, osteoblasts andosteocytes might die in way of apoptosis-rising bonehipermineralization. The amount of collagen fibersdecreases with age, but also during osteoporosis andsuch, and remodeled bone become easier damaged(Schnitzler et al., 2005).Finally, proliferation of connective tissue andblood vessels in Haversian channels seen in almostall cow bones also demonstrate the role of somegrowth factors like FGF that is described to stimulateproliferation of endothelial cells, angiogenesis, andeven development of granulative tissue (Kawamata etal., 1997).In such a way, we observed an important forseemingly healthy dairy cows row of structuralchanges in bones that bring some new understandingabout real welfare of these animals. Despite theimportance of skeleton for cows, research on itsstructure, changes and possible origin of variousdiseases has been relatively neglected up to now andshould be investigated more in future.Conclusions1. Main changes in bone of healthy dairy cowsdemonstrate variations in number of osteocytesper mm 2 (mainly increase), variation in diameterof osteones and different bone density intrabecules, intensive proliferation of connectivetissue, and abundance of small capillaries inosteon channels, which proves the morphologicalpicture of regional osteoporosis in long boneswith changed calcium and phosphate relation.2. Bone morphogenetic proteins are expressed inboth articular cartilage and bone where growthof supportive tissue is stimulated and selectivelydoesn’t correlate with changes of other growthfactors.3. FGFR, apoptosis, MMP2, and MMP 9 affectthe articular cartilage more than the long bonein healthy cows despite the unchanged cartilagestructure in routine morphology. Apoptosis anddegradation of supportive tissue matrix by MMPseem to correlate, but increased expression ofFGFR indicates more compensatory defensereaction on damage of articular cartilage and longbones in seemingly healthy cows.Literature1. Beighle, D. E. (1999) The effects of gestationand lactation on bone calcium, phosphorus andmagnesium in dairy cows. J. S. Afr. Vet. Assoc.,vol. 70, pp. 142-146.2. Bellino, F. L. (2000) Nonprimate animal modelsof menopause: workshop report. Menopause,No. 7, pp. 14-24.3. Benzie, D., Boyne, A. W., Dalgarno, A. C.,Duckworth, J. M., Hill, R., and Walker, D.M. (1955) The effect of different levels ofdietary calcium during pregnancy and lactationon individual bones. J. Agric. Sci., vol. 46,pp. 425-439.4. Borland, C. Z., Schutzman, J. L., Stern, M. J.(2001) Fibroblast growth factor signaling inCaenorhabditis elegans. BioEssays, vol. 23,pp.1120-1130.5. Bottcher, R. T., Niehrs, C. (2005) Fibroblastgrowth factor signaling during early vertebratedevelopment. Endocr. Rev., vol. 26, pp. 63-77.6. Buckwalter, J. A., Glimcher, M. J., Cooper, R.R., and Recker, R. (1996) Bone biology. Part II:Formation, form, modelling, remodelling andregulation of cell function. Instr. Course Lect.,vol. 45, pp. 387-399.7. Donath, K., Breuner, G. (1982) A method forthe study of undecalcified bones and teeth withattached soft tissue. J. Oral Pathol., vol. 11,pp. 318-326.8. Dou, Z. (2006) NE-132 Regional Project.Report 2006. Pennsylvania Penn, University ofPennsylvania: cahpwww.vet.upenn.edu/nerp132/reports/r2006/pa-penn – accessed on March 13,2007.9. Ekelund, A., Spörndly, R., Valk, H., andMurphy, M. (2003) Influence of feeding variousphosphorus sources on apparent digestibilityof phosphorus in dairy cows. Anim. Feed. Sci.Technol., vol. 109, No. 1-4, p. 95.10. Frenz, D. A., Liu, W., Williams, J.D.,Hatcher. V., Galinovic-Schwartz, V.,Flanders, K. C., and Van de Water, TR. (1994)FGF Induction of chondrogenesis: requirementfor synergistic interaction of basic fibroblastgrowth factor and transforming growth factorbeta.Development, vol. 120(2), pp. 415-424.11. Fromigue, O., Modrowski, D., Marie, P.J. (2005)Apoptosis in Membranous Bone Formation:Role of Fibroblast Growth Factor and BoneMorphogenetic Protein Signaling. Crit.Rev. Eukaryot. Gene Expr., vol. 15, issue 1,pp. 75-96.12. Frost, H. M. (1992) Perspectives: bone’smechanical usage windows. Journal of Bone andMineral Research, vol. 19, pp. 257-271.56LLU Raksti 18 (313), 2007; 51-57