In comparison to skin fibroblasts from normal subjects, those from patients with cystic fibrosis (CF): (1) bound [20-3H] phorbol 12,13-dibutyrate (PDBu) with a higher affinity (Kd=25.8 vs 12.8 nM respectively) but expressed a similar number of total phorbol ester binding sites (about 2.5 pmol PDBu bound/mg of protein); (2) exhibited a faster and higher response to 4?-phorbol 12?-myristate 13?-acetate (PMA) for the stimulation of [35S]-labelled glycoconjutate release, but were equally sensitive to the synergistic effect of A23187 on this process; and (3) secreted glycoconjugates with similar [35S]-sulfate and [14C]-leucine to [14C]-glucosamine labelling ratios. Taken together, these results provide further evidence for abnormal protein kinase C (PKC) regulation of macromolecule secretion in CF disease.

Abbreviations BSA, Bovine serum albumin; DBcAMP, Dibutyryl cyclic AMP; DMEM, Dulbecco's modified Eagle's medium; DMSO, Dimethylsulfoxide; LDH, Lactate dehydrogenase; PBS, Phosphate-buffered saline; PDBu, 4?-phorbol 12,13-dibutyrate; 4?-PDD, 4?-phorbol 12,13-didecanoate; PMA, 4?-phorbol 12?-myristate 13?-acetate; TCA, Trichloroacetic acid

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