CONNECTIVE-TISSUE INTEGRITY IS LOST IN VITAMIN-B-6-DEFICIENT CHICKS

The objective of the present investigation was to characterize further the connective tissue disorder produced by pyridoxine (vitamin B-6) d eficiency, as previously evidenced by electron microscopy. Following t he second post-natal week, fast growing male chicks were deprived of p yridoxine for a 1-mo period. Six weeks post-natally, blood concentrati ons in the experimental deficiency group had declined to deficiency le vels as registered by low concentrations of pyridoxal phosphate (coenz yme form) in erythrocytes, but did not reach levels associated with ne urological symptoms. Light microscopic study showed abnormalities in t he extracellular matrix of the connective tissues. Collagen cross-link s and the aldehyde contents were not significantly lower in cartilage and tendon collagens of vitamin B-6-deficient animals than in age-matc hed controls; also, their proteoglycan degrading protease and collagen ase activities measured in articular cartilages were not greater. Thus , proteolysis was an unlikely alternative mechanism to account for the loss of connective tissue integrity. These results point to the need for further investigation into adhesive properties of collagen associa ted proteoglycans or other proteins in vitamin B-6-deficient connectiv e tissue.