Fluid Transport Mechanisms in Breast Gross Cystic Disease
Abstract
The goal of the present work was to develop a model system to study the mechanisms of fluid transport across mammary epithelia. In addition we also examined whether the epithelial ion Cl and Na channels (cystic fibrosis transmembrane conductance regulator, CFTR, and ENaC, respectively) contribute to the ion and fluid transport properties of the mammary epithelial cell line 31EG4. We reasoned that since the mammary gland is a modified sweat gland (Pfeifer et al., 1999. Van Der Putte et al., 1995), embryologically derived from sweat glands, with similar functions it may utilize many of the same plasma membrane transport proteins to carry out those functions. Since sweat duct cells express high levels of both CFTR and ENaC to allow reabsorption of salt from the fluid that flows down the duct (Soos,1995), 31EG4 cells might also express these ion channels and use them to control the ionic and fluid composition of milk. We used PCR to identify the genes, western blot and immunomicroscopy to identify the proteins and transepithelial, microelectrode and patch clamp electrophysiology to demonstrate the appropriate ionic currents. Fluid transport was measured using a capacitance probe method to determine whether ENaC and CFTR also play roles in the transport of fluid across the monolayers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1999
- Accession Number
- ADA382765
Entities
People
- Sheldon S. Miller
Organizations
- University of California, Berkeley