A HISTOCHEMICAL AND RADIOAUTOGRAPHIC STUDY OF THE PARTICIPAPATION OF FIBROBLASTS IN THE PRODUCTION OF MUCOPOLYSACCHARIDES IN CONNECTIVE TISSUE

Abstract

A histochemical and radioautographic study of the connective tissue of rat skin was carried out from birth to maturity. The following observations were made: 1) Early fibroblasts changed into typical adult connective tissue cells, fibrocytes, with gradual diminution of cytoplasmic nucleoproteins, periodic acid Schiff positive material, succinodehydrogenase, β-glucuronidase and leucyl-aminopeptidase. 2) Lack of striking morphological or cytochemical changes of the mast cells in the different ages as compared with fibroblasts, but more intense enzymatic reactions with respect to succinodehydrogenase, β-glucuronidase, leucyl-aminopeptidase, alkaline and acid phosphatase, lipase esterase and cytochrome oxydase were found. 3) Using adenine-C¹⁴ and methionine-S³⁵, the localization of these substances was seen more in the fibroblasts and mast cells than in the intercellular ground substance; in the fibroblasts the uptake was higher in the embryonic and early postnatal connective tissues than in the adult. 4) The embryonic and early postnatal connective tissues to synthesize sulphated polysaccharides trapped more S³⁵ than the adult. S³⁵ was seen first in the fibroblasts and then in the intercellular ground substance. The same results were observed in tissue cultures of fibroblasts. Mast cells incorporated and stored more S³⁵ than fibroblasts, but there was no appreciable difference in their capacity for this at various ages, as there was in fibroblasts.