Bone Development in Normal and Rachitic Rats

Abstract

Radii were obtained from albino rats in a stock colony ration at 3-day intervals for the age period of 3 days to 54 days, inclusive. From 24 to 54 days of age, inclusive, rats from the stock colony were fed the Steenbock rachitogenic ration 2965 and the radii taken at 3-day intervals. The split, stained radii were photographed and the average width of the epiphyseal cartilage measured. This value for the stock colony animals decreased continuously and tended to become constant after 36 days of age. The narrowing of the epiphyseal cartilage ceased within 3 days after the animals were placed on the rechitogenic ration and a widening process began which continued for 18 to 27 days (42 to 51 days of age) after which there was no further widening of the cartilage. There was a marked retardation of the growth rate immediately after the animals were placed on the rachitogenic ration.