Pathological Defects in the Epiphyseal Cartilage of Zinc-deficient Chicks

Abstract

The objectives of this study were: 1) to compare the epiphyseal plates of the tibiotarsus and also the hock synovia of zinc-deficient and control chicks, 2) to gain information on the site of action of histamine and indomethacin, which were found previously to alleviate significantly the leg abnormalities caused by zinc deficiency, and 3) to compare the epiphyseal plates of zinc-deficient chicks with those from chicks deficient in manganese and in vitamin D. In the proliferating region of the epiphyseal plate of zinc-deficient chicks, the cartilage cells that were near blood vessels were normal, whereas cells remote from vessels were larger and rounder and were separated by more extracellular matrix. In these chicks the cells of the degenerating region of the epiphyseal plate did not degenerate normally unless they were near a blood vessel. In cross section these defects caused a characteristic and easily discernible “bull's eye” appearance around each blood vessel. This was not seen in tissue from manganese- or vitamin D-deficient chicks. Neither histamine nor indomethacin corrected the fundamental lesion due to zinc deficiency; however, the gross defect was alleviated. No hyperplasia or inflammation of the synovia due to zinc deficiency was observed.