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New photic stimulating system with white light-emitting diodes to elicit electroretinograms from zebrafish larvae.

Potential protective function of the sterol regulatory element binding factor 1-fatty acid desaturase 12 axis in early-stage age-related macular degeneration

Activation of Sterol Regulatory Element Binding Factors by Fenofibrate and Gemfibrozil Stimulates Myelination in Zebrafish

Downregulation of GSTK1 Is a Common Mechanism Underlying Hypertrophic Cardiomyopathy

Comparative Transcriptome Analysis Identifies CCDC80 as a Novel Gene Associated with Pulmonary Arterial Hypertension

tChanges in Cyclic Nucleotide Phosphodiesterase Activity and Calmodulin Concentration in Heart Muscle of Cardiomyopathic Hamsters.


Rumi Masunaga, Akio Nagasaka, Yoshikuni Sawai, Nobuki Hayakawa, Akira Nakai, Keiko Hotta, Yasuchika Kato, Hitoshi Hishida, Hisahide Takahashi, Michiko Naka, Yasuhito Shimada, Toshio Tanaka, Hiroyoshi Hidaka and Mitsuyasu Itoh.
J Mol Cell Cardiol.;37(3):767-774 2004


Cyclic nucleotides (cAMP and cGMP) phosphodiesterase (PDE) activities and expression are altered in the cardiac muscle of cardiomyopathic heart failure, and PDE inhibitors improve the abnormal muscle condition through changing the cyclic nucleotide concentration. These observations prompted us to investigate the role of calmodulin (CaM) in the regulation of cyclic nucleotide PDE activities, and moreover to study the modulation of the PDE isozymes in heart failure, using cardiac muscles of cardiomyopathic hamster. The CaM concentrations in the heart muscle of the normal control and cardiomyopathic hamsters (each of three to four hamsters) varied with cell fraction and with the age of the animal. The CaM concentrations in the soluble fraction obtained from cardiomyopathic hamster tissue were significantly increased at 25 and 32 weeks of age (2.02 +/- 0.62 microg/mg protein (mean +/- S.E.), and 3.21 +/- 0.95) compared with that obtained from the control (0.60 +/- 0.04) or cardiomyopathic (0.95 +/- 0.12) hamsters at 8 weeks of age. The solubilized PDE isolated from the hamster heart muscle (three or four hamsters in each age) by column chromatography on diethylaminoethyl (DEAE)-cellulose revealed three peaks of activity, which may correspond to the isozymes of PDE classified recently, namely PDE I, II, and III. These three peaks of activity, particularly peak III, seen in the soluble fraction of cardiomyopathic hamster heart declined in proportion to the age of the animal compared with that of the control hamster heart. In the cGMP-PDE assay system, the concentration of CaM inhibitor W-7 required for 50% inhibition (IC(50)) of PDE I, II, and III peak activities was 140, 29, and 46 microM, respectively, suggesting that PDE II is more sensitive to W-7. These results suggest that alteration in these isozyme activities accompanied with changes of CaM concentration may influence the cardiac muscle contractility in cardiomyopathic hamster via changes of cyclic nucleotide concentration.