Complex saccharide metabolism in cystic fibrosis fibroblasts.

There are several reports of secretory and other abnormalities present in cultured 
fibroblasts from patients with cystic fibrosis (CF). We have, therefore, investigated 
aspects of complex saccharide synthesis and secretion by such cells compared 
with fibroblasts derived from heterozygous (HZ) parents and from normal (N) 
children. The main glycosaminoglycans produced by skin fibroblasts during in vitro 
culture were hyaluronic acid, heparan sulfates, and dermatan sulfate-like materials. Using 
double-label experiments with D-[3H]- or [14c]glucosamine and analyzing the products by 
ion exchange chromatography, it was shown for five CF, two HZ, 
and four N lines that these polysaccharides were secreted into the 
medium in approximately similar proportions to each other. Moreover, experiments in 
which three CF, nine HZ, and three N lines were grown 
in log phase for up to 5 days in the presence 
of [35S]sulfate and [3H]glucosamine indicate that, during such a period, CF 
fibroblasts do not secrete complex carbohydrates at rates significantly different from 
N or HZ cells. Neither do such cells shown an abnormal 
intracellular accumulation of complex carbohydrates. The latter observation was further confirmed 
by preparing whole cell autoradiographs during growth of six CF, two 
HZ, and three N lines in the presence of D-[3H]glucosamine and, 
subsequently, after addition of unlabeled medium. 