Changes in Endochondral Ossification of the Tibia Accompanying Acute Pantothenic Acid Deficiency in Young Rats. ∗ †

Abstract

Summary

The changes in endochondral ossification of the tibia accompanying acute pantothenic acid: deficiency in young rats have been investigated. Twenty deficient animals, 13 male and 7 female rats, were autopsied together with their controls at ages ranging from 3 to 16 weeks. The histologic changes observed were decreased growth of the tibia with marked impairment in chondrogenesis, osteogenesis and hematopoiesis.

Four stages of morphologic changes were observed. Stage I, in which the ages of the rats ranged from 21 to 33 days, was characterized by unusual trabecular resorption, decreased osteoblast proliferation and edema of the bone marrow. In Stage II the ages ranged from 33 to 63 days and marked retardation of osteogenesis with some calcification in the epiphysis and blunt diaphyseal trabeculae was observed. The dominant feature of Stage III, from 45 to 72 days, was the beginning of epiphyseal cartilage calcification and the cessation of osteogenesis. Stage IV, from 78 to 109 days, was characterized by complete absence of trabeculae and the formation of a heavy layer of sealing-off bone below the epiphyseal cartilage.

The role of pantothenic .atid and off additional factors such as pteroylglutamic acid, unknown vitamins and caloric restriction in these histologic changes is discussed.