Calcium-dependent phosphodiesterase 1C inhibits renin release from isolated juxtaglomerular cells

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 2009-11, Vol.297 (5), p.R1469-R1476
• Main Authors: Ortiz-Capisano, M. Cecilia, Liao, Tang-Dong, Ortiz, Pablo A, Beierwaltes, William H
• Format: Article
• Language: English
• Subjects: 1-Methyl-3-isobutylxanthine - pharmacology; Animals; Calcium; Calmodulin - antagonists & inhibitors; Cells; Cells, Cultured; Cinacalcet Hydrochloride; Cyclic AMP - metabolism; Cyclic Nucleotide Phosphodiesterases, Type 1 - antagonists & inhibitors; Cyclic Nucleotide Phosphodiesterases, Type 1 - metabolism; Fluorescence; Juxtaglomerular Apparatus - cytology; Juxtaglomerular Apparatus - drug effects; Juxtaglomerular Apparatus - metabolism; Mice; Mice, Inbred C57BL; Naphthalenes - pharmacology; Phosphodiesterase Inhibitors - pharmacology; Proteins; Receptors, Calcium-Sensing - metabolism; Renin - metabolism; Sulfonamides - pharmacology; Vinca Alkaloids - pharmacology
• ISSN: 0363-6119; 1522-1490
• DOI: 10.1152/ajpregu.00121.2009

Department of Medicine, Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, Michigan Submitted February 25, 2009 ; accepted in final form September 3, 2009 Renin release from the juxtaglomerular (JG) cell is stimulated by the second messenger cAMP and inhibited by calcium. We previously showed JG cells contain a calcium sensing receptor (CaSR), which, when stimulated, decreases cAMP formation and inhibits renin release. We hypothesize CaSR activation decreases cAMP and renin release, in part, by stimulating a calcium calmodulin-activated phosphodiesterase 1 (PDE1). We incubated our primary culture of JG cells with two selective PDE1 inhibitors [8-methoxymethil-IBMX (8-MM-IBMX; 20 µM) and vinpocetine (40 µM)] and the calmodulin inhibitor W-7 (10 µM) and measured cAMP and renin release. Stimulation of the JG cell CaSR with the calcimimetic cinacalcet (1 µM) resulted in decreased cAMP from a basal of 1.13 ± 0.14 to 0.69 ± 0.08 pM/mg protein ( P < 0.001) and in renin release from 0.89 ± 0.16 to 0.38 ± 0.08 µg ANG I/ml·h –1 ·mg protein –1 ( P < 0.001). However, the addition of 8-MM-IBMX with cinacalcet returned both cAMP (1.10 ± 0.19 pM/mg protein) and renin (0.57 ± 0.16 µg ANG I/ml·h –1 ·mg protein –1 ) to basal levels. Similar results were obtained with vinpocetine, and also with W-7. Combining 8-MM-IBMX and W-7 had no additive effect. To determine which PDE1 isoform is involved, we performed Western blot analysis for PDE1A, B, and C. Only Western blot analysis for PDE1C showed a characteristic band apparent at 80 kDa. Immunofluorescence showed cytoplasmic distribution of PDE1C and renin in the JG cells. In conclusion, PDE1C is expressed in isolated JG cells, and contributes to calcium's inhibitory modulation of renin release from JG cells. angiotensin; calmodulin; phosphodiesterase; cAMP; adenylyl cyclase Address for reprint requests and other correspondence: W. H. Beierwaltes, Henry Ford Hospital, Dept. of Medicine, Hypertension and Vascular Research Division. 7121 E&R Bldg., 2799 W. Grand Blvd., Detroit, MI 48202 (e-mail: wbeierw1{at}hfhs.org ).