Cyclic nucleotides and calmodulin-phosphodiesterase activator: potential biochemical markers of salt sensitivity.

Salt sensitivity affects a fraction of hypertensive and normotensive subjects, but biochemical markers that target salt-sensitive individuals are not available at present. The aim of these studies was to establish if calmodulin-phosphodiesterase (CaM-PDE) activator (J Clin Invest 82: 276, 1988) and platelet cyclic nucleotides could serve as potential markers of salt sensitivity. The results demonstrated that CaM-PDE activator was increased in the heart of Dahl salt-sensitive rats (DS/JR) compared to Dahl salt-resistant (DR/JR) animals fed a 1% sodium diet. Normotensive male Wistar rats given a low (0.15%) or high (3.5%) sodium diet from age 7 weeks to 11 weeks presented significant increases (p < 0.01) of three parameters: blood pressure (from 106 ± 4 to 128 ± 8 mmHg); platelet aggregation in response to ADP and thrombin; and CaM-PDE activator levels (from 1.57 ± 0.14 to 2.8 ± 0.18). Basal as well as stimulated cyclic nucleotide levels were significantly reduced in rats fed the high sodium diet. Since the...