Influence of excess vitamin A on the suplhate metabolism of bone rudiments grown in vitro / by H.B. Fell, E. Mellanby, and S.R. Pelc.

  • Fell, Honor B.
Date:
[1956?]
Catalogue details

Licence: In copyright

Credit: Influence of excess vitamin A on the suplhate metabolism of bone rudiments grown in vitro / by H.B. Fell, E. Mellanby, and S.R. Pelc. Source: Wellcome Collection.

    1/12
    [Reprinted from the Journal of Physiology, 1956, Yol. 134, No. 1, p. 179.] PRINTED IN GREAT BRITAIN J. Physiol. (1956) 134, 179-188 INFLUENCE OF EXCESS VITAMIN A ON THE SULPHATE METABOLISM OF BONE RUDIMENTS GROWN IN VITRO By H. B. FELL, the late E. MELLANBY and S. R. PELC* From the Strangeways Research Laboratory, Cambridge; The Nutrition Building, National Institute for Medical Research; the Medical Research Council, Experimental Radiopathology Research TJnit, London (.Received 30 May 1956) In organ culture experiments, Fell & Mellanby (1952) found that when vita¬ min A was added to the culture medium (+ A medium) of long-bone rudiments from chick and mouse embryos, -the intercellular material of the cartilage rapidly lost its capacity for metachromatic staining, shrank and finally disinte¬ grated; the chondroblasts usually appeared healthy throughout this process. Later, the effect of excess vitamin A on the differentiation in vitro of the early embryonic epidermis of the chick was investigated (Fell & Mellanby, 1953); in normal medium the ectoderm formed squamous, keratinizing epi¬ thelium, but in + A medium keratinization was suppressed and the epithelium developed into a mucus-secreting, often ciliated membrane resembling the normal nasal mucosa. The transformation of the epidermis into a mucous instead of a keratinizing epithelium was accompanied by a profound alteration in the sulphate meta¬ bolism (Fell, Mellanby & Pelc, 1954). This was shown by treating ectodermal explants, grown in +A and in normal medium respectively, with labelled sodium sulphate (Na235S04) and studying the distribution of the isotope by means of autoradiographs (ARG). In the present investigation similar experi¬ ments were made to elucidate the sulphate metabolism of long-bone rudiments grown in normal and in +A medium. For comparison, the in vivo uptake of sulphate in the long bones of chick embryos was studied. MATERIALS AND METHODS Femora and tibiae from 6-day chick embryos were grown by the watch-glass method (Fell & Robison, 1929; Fell & Mellanby, 1952) in a mixture of 3 parts of fowl plasma and 1 part of chick embryo extract. This mixture was supplemented with approximately 0*2 % of glucose. Normal medium contained 250-300 i.u. of vitamin A/100 ml., and +A medium 2800-3000 i.u./lOO ml. The rudiments were transferred to fresh medium every 2 days. Labelled sulphate was obtained;