Digoxinlike materials in human breast cyst fluids.
Digoxinlike materials (DLMs) are compounds found in animals that (1) cross-react with digoxin antibodies in specific radioimmunoassay procedures and (2) bind to Na+, K(+)-ATPase and inhibit its activity. DLMs may play a part in the regulation of electrolyte composition. We have determined DLM concentrations in breast cyst fluids and found that these fluids were a rich source of DLMs. Total DLMs were elevated in fluids with type 1 electrolyte composition (high K+ and low Na+ content) when compared to fluids with type 2 composition (low K+ and high Na+ content). Chromatographic studies showed that the basis for the increase was the presence of an additional DLM in the type 1 cyst fluids rather than an increased concentration of the same DLM present in both types of fluids. We propose that this additional DLM may have a role in the accumulation of K+ ions in type 1 fluids. In addition, 7 of 80 cyst fluid samples subjected to high-performance liquid chromatography had a large UV-absorbing peak at 6.4 minutes. Four of these samples were taken from women who later developed breast cancer; information on the subsequent medical history of the other 3 women was unavailable. We suggest that the presence of this material in cyst fluid may be a marker of risk for development of breast cancer.
Chasalow
F I
FI
Schneider Children's Hospital of Long Island Jewish Medical Center, Albert Einstein College of Medicine, New Hyde Park, New York 11042.
Bradlow
H L
HL
D014408:Biomarkers, Tumor / Q000032:analysis; D001798:Blood Proteins / Q000032:analysis*; D002298:Cardenolides; D002851:Chromatography, High Pressure Liquid; D004077:Digoxin; D005122:Exudates and Transudates / Q000032:analysis*; D005260:Female; D005348:Fibrocystic Breast Disease / Q000032:analysis* / Q000145:classification; D006801:Humans; D011188:Potassium / Q000032:analysis; D011863:Radioimmunoassay; D012503:Saponins; D012964:Sodium / Q000032:analysis; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D014408:Biomarkers, Tumor; D001798:Blood Proteins; D002298:Cardenolides; D012503:Saponins; C034504:digoxin-like factors; D004077:Digoxin; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium