KIDNEY AND BREAST CYSTS - A COMPARATIVE-STUDY OF FLUIDS

The contributions of amino acids to the overall osmotic activity of cy st fluids were sought in this comparative study of fluids from the cys ts of autosomal dominant polycystic disease (ADPKD) and gross cystic d isease of the breast (GCDB). Fluids (n = 18) from 18 women with GCDB a nd from 8 patients with ADPKD (n = 25), grouped on the basis of sodium concentrations, were analyzed for potassium, chloride, protein, and o smolality by routine methods and for amino acids by reversed-phase hig h-pressure liquid chromatography. Similarities between kidney and brea st cyst fluids included relative isosmolality, a wide range of sodium concentrations, an inverse relationship between sodium and potassium c oncentrations, higher concentrations of amino acids in low-sodium flui ds, and significant correlations between sequential concentrations of amino acids in cyst fluids versus blood and some of its components. Th erefore, cyst fluids in ADPKD and GCDB share compositional characteris tics, and amino acids, possibly of blood protein origin, accumulate in small but osmotically significant amounts in some, particularly low-s odium, cysts of kidney and breast.