EXOGENOUS SPERMIDINE MODULATES GLYCOSAMINOGLYCAN ACCUMULATION AND EPITHELIAL DIFFERENTIATION IN CHICK EMBRYONIC SKIN

We have previously shown that feather formation in chick embryonic ski n depends on accumulation of sulphated glycosaminoglycans in the under lying mesenchyme, and that addition of spermidine to chick embryo fibr oblasts increases the extracellular sulphated glycosaminoglycans. In t he present work, using histological, histochemical and biochemical pro cedures, we have investigated the effects on glycosaminoglycan accumul ation and on epithelial differentiation of adding spermidine and bis-c yclohexylammonium sulphate, a spermidine inhibitor, to embryonic chick skin cultures. Our results demonstrate that spermidine induces an acc umulation of sulphated glycosaminoglycan and an increase in feather fo rmation, suggesting that the morphogenetic effect of spermidine may be dependent on specific glycosaminoglycan accumulation. (C) 1998 Wiley- Liss, Inc.