CURRENT BIOCHEMICAL APPROACHES IN CYSTIC-FIBROSIS RESEARCH

Recent directions in cystic fibrosis studies have included a search for an abnormal functional protein, an enzyme deficiency or a deficiency of a normal inhibitor. A circulating factor in cystic fibrosis serum which causes asynchrony in ciliary beats was described in rabbit trachea, the gills of Crassostrea virginica, and Dreissensia. A substance from the sweat and saliva of cystic fibrosis patients which inhibited Na reabsorption in rat parotid gland and excised sweat glands from normal and cystic fibrosis subjects was described. A factor in parotid secretions of cystic fibrosis homozygotes significantly reduced the zeta potential, which is related to the net electrical charge on mucous colloid particles. EM and transmission electron microscopy utilized to study the effect of cystic fibrosis factor(s) on mucous properties and secretion in oyster ciliated epithelium. It was suggested that arginine esterase is deficient in homozygotes'' plasma and 1 of 2 normal components was reduced to 30% of normal activity. Alterations in polyamine content in the blood and blood cells of cystic fibrosis patients was described. Whether the mucous composition is different in cystic fibrosis and, if so, what is the basis for the glycoprotein alteration is under investigation. It is anticipated that the basic defect will be related to a membrane disturbance.