TY - JOUR
T1 - Renal accumulation and excretion of cyclic adenosine monophosphate in a murine model of slowly progressive polycystic kidney disease
AU - Yamaguchi, Tamio
AU - Nagao, Shizuko
AU - Kasahara, Masao
AU - Takahashi, Hisahide
AU - Grantham, Jared J.
N1 - Funding Information:
Male DBN2FGpcy/pcy mice were used in this study to normalize the effects of gender. The animals were housed From the Fujita Health University School of Medicine, Toyoake, Aichi, Japan, and Kansas University Medical Center, Kansas City, KS. Received March 17, 1997; accepted in revised form June 20, 1997. Supported by NIH grant DK 13476. Address reprint requests to Jared J. Grantham, MD, Kansas University Medical Center, Department of Medicine-Sudler 401.5, Kansas University Medical Center, 3901 Rainbow Blvd, Kansas City, KS 66160. 0 1997 by the National Kidney Foundation, 0272-6386/97/3005-0015$3.00/O
PY - 1997/11
Y1 - 1997/11
N2 - Evidence from in vitro studies indicates that increased proliferation of epithelial cells and secretion of fluid by these cells may be important factors in the progressive enlargement of renal cysts. The rate of cellular proliferation and fluid secretion by cyst epithelium in vitro can be strikingly accelerated by cyclic adenosine 3'5' monophosphate (cAMP) and agonists that lead to the production of this nucleotide. The extent to which renal cAMP content is increased in polycystic kidneys is unknown. In the current study, we determined the amount of this nucleotide in intact kidneys, cyst fluid, plasma, and urine in nonazotemic mice (DBA/2FG-pcy/pcy) with a slowly progressive form of inherited polycystic kidney disease (PKD). In 45 pcy/pcy mice studied 20, 45, or 70 days after birth, the total kidney cAMP content was 0.22 ± 0.01, 0.46 ± 0.02, and 0.90 ± 0.05 pmol/mg tissue, respectively. By contrast, in 37 control DBA/2J mice the levels of cAMP at identical times remained relatively constant at 0.22 2+ 0.01, 0.21 ± 0.01, and 0.29 ± 0.01 pmol/mg tissue, respectively. In 70-day-old nonazotemic pcy/pcy mice with normal serum levels of parathyroid hormone, cAMP generated by the kidneys (nephrogenous cAMP) was 22.9 ± 2.8 nmol/100 mL creatinine clearance, compared with 6.5 ± 1.3 in normal animals of the same age (P < 0.001). The cyst fluids of 70-day-old pcy/pcy mice contained a lipid that increased transepithelial secretion of fluid by MDCK monolayers from a baseline of 0.012 ± 0.002 to 0.136 ± 0.008 μL/cm2/hr (P < 0.05). This lipid also stimulated cellular proliferation by monolayers of cultured MDCK and LLC-PK1 cells 2.5- and 7.9-fold (P < .05), respectively, and stimulated cAMP accumulation by these cells 1.6- and 2.0-fold (P < .05), respectively. These studies illustrate that renal cAMP production and excretion increase in concert with the cystic enlargement of the kidneys in DBA/2FG-pcy/pcy mice and identify a lipid cAMP agonist in murine renal cystic kidney disease.
AB - Evidence from in vitro studies indicates that increased proliferation of epithelial cells and secretion of fluid by these cells may be important factors in the progressive enlargement of renal cysts. The rate of cellular proliferation and fluid secretion by cyst epithelium in vitro can be strikingly accelerated by cyclic adenosine 3'5' monophosphate (cAMP) and agonists that lead to the production of this nucleotide. The extent to which renal cAMP content is increased in polycystic kidneys is unknown. In the current study, we determined the amount of this nucleotide in intact kidneys, cyst fluid, plasma, and urine in nonazotemic mice (DBA/2FG-pcy/pcy) with a slowly progressive form of inherited polycystic kidney disease (PKD). In 45 pcy/pcy mice studied 20, 45, or 70 days after birth, the total kidney cAMP content was 0.22 ± 0.01, 0.46 ± 0.02, and 0.90 ± 0.05 pmol/mg tissue, respectively. By contrast, in 37 control DBA/2J mice the levels of cAMP at identical times remained relatively constant at 0.22 2+ 0.01, 0.21 ± 0.01, and 0.29 ± 0.01 pmol/mg tissue, respectively. In 70-day-old nonazotemic pcy/pcy mice with normal serum levels of parathyroid hormone, cAMP generated by the kidneys (nephrogenous cAMP) was 22.9 ± 2.8 nmol/100 mL creatinine clearance, compared with 6.5 ± 1.3 in normal animals of the same age (P < 0.001). The cyst fluids of 70-day-old pcy/pcy mice contained a lipid that increased transepithelial secretion of fluid by MDCK monolayers from a baseline of 0.012 ± 0.002 to 0.136 ± 0.008 μL/cm2/hr (P < 0.05). This lipid also stimulated cellular proliferation by monolayers of cultured MDCK and LLC-PK1 cells 2.5- and 7.9-fold (P < .05), respectively, and stimulated cAMP accumulation by these cells 1.6- and 2.0-fold (P < .05), respectively. These studies illustrate that renal cAMP production and excretion increase in concert with the cystic enlargement of the kidneys in DBA/2FG-pcy/pcy mice and identify a lipid cAMP agonist in murine renal cystic kidney disease.
UR - http://www.scopus.com/inward/record.url?scp=0030723843&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030723843&partnerID=8YFLogxK
U2 - 10.1016/S0272-6386(97)90496-0
DO - 10.1016/S0272-6386(97)90496-0
M3 - Article
C2 - 9370187
AN - SCOPUS:0030723843
SN - 0272-6386
VL - 30
SP - 703
EP - 709
JO - American Journal of Kidney Diseases
JF - American Journal of Kidney Diseases
IS - 5
ER -