Cyst fluid from a murine model of polycystic kidney disease stimulates fluid secretion, cyclic adenosine monophosphate accumulation, and cell proliferation by Madin-Darby canine kidney cells in vitro.

Cyst fluids from subjects with autosomal dominant polycystic kidney disease (ADPKD) cause polarized monolayers of MDCK cells to secrete fluid toward the apical compartment in vitro. To determine the extent to which secretagogue accumulation may be a general feature of polycystic diseases, cyst fluid from mice with a slowly progressive form of hereditary PKD (DBA/2FG-pcy/pcy) was added to polarized MDCK monolayers. Basolateral application of cyst fluids (diluted with culture medium to 15% final concentration) from 13 different animals 16 to 35 weeks old increased the fluid secretion rate from a baseline of 0.023 +/- 0.003 to 0.111 +/- 0.017 microL/cm2/h (P < 0.005). There was a direct relation between the concentration of cyst fluid and the rate of net fluid secretion. The secretory activity of cyst fluid was not altered by pronase treatment or boiling. Cyst fluid (10%) added to the basolateral surfaces of polarized MDCK monolayers for 24 hours increased cell cyclic adenosine monophosphate (AMP) levels from a baseline of 6.3 +/- 0.2 to 17.3 +/- 0.3 pmoles/monolayer (n = 3, P < 0.05). The capacity of cyst fluid to increase cyclic AMP levels was not changed by pronase treatment or boiling. There was a direct relation between the level of cellular cyclic AMP and the rate of transepithelial fluid secretion caused by cyst fluid. Cyst fluid increased thymidine incorporation by Madin-Darby canine kidney (MDCK) cells to an extent equal to that caused by epidermal growth factor and caused MDCK cells to form cysts in collagen matricies.(ABSTRACT TRUNCATED AT 250 WORDS)