VITAMIN-B-6 DEFICIENCY EXPERIMENTALLY-INDUCED BONE AND JOINT DISORDER- MICROSCOPIC, RADIOGRAPHIC AND BIOCHEMICAL-EVIDENCE

In the present study the effect of pyridoxine deficiency on the ultras tructure and morphology of bone and its metabolism was examined in the rapidly growing chick. Pyridoxine-deficient animals had tibias of red uced dry weight and cortical thickness. Histomorphometry demonstrated a disproportionately high eroded surface, lower amount of osteoid tiss ue and reduced mineralized trabecular width. Anterior-posterior radiog raphs of the tibiotarsometatarsal joint showed reduced secondary ossif ication centres and coarse trabeculation. Decalcified metaphyseal cart ilage showed irregular trabeculas and a markedly reduced amount of Fas t-green counterstain matrix suggesting that there is less collagen pre sent and in turn less availability for matrix to be laid down for late r calcification. Plasma activity of the bone alkaline phosphatase isoe nzyme (EC 3.1.3.1) was decreased. Plasma Ca and PO4 levels did not var y. The present bone study referring to a pseudo-lathyritic state in wh ich collagen maturation is not completely achieved supports the hypoth esis that pyridoxine is an essential nutrient for the connective tissu e matrix.