title: Platelet cAMP and cGMP in essential hypertension.
abstract: Vasodilator substances released in the blood vessel wall, such as the endothelium-derived relaxing factor (EDRF) and prostacyclin (PGI2), may participate in the regulation of arterial blood pressure. However, their role in the pathogenesis of human essential hypertension to date remains unclear. For some of these factors affecting vascular smooth muscle cells, blood platelets represent a second target tissue. Thus, EDRF and PGI2 inactivate platelets by stimulation of cyclic guanosine-5'-monophosphate (cGMP) and cyclic adenosine-5'-monophosphate (cAMP) synthesis, respectively. In the present study, platelet cAMP (n = 68) and cGMP (n = 60) were determined in a control group of healthy subjects (C) and in 12 patients with untreated essential hypertension (EH). In the control group, platelet cAMP and cGMP content averaged 13.52 +/- 0.38 and 1.48 +/- 0.06 pmol/10(9) platelets and no dependence of either variable on sex or age could be established. Furthermore, cGMP levels were similar in EH as compared to the control group (1.38 +/- 0.11 pmol/10(9) platelets). However, intracellular concentrations of cAMP were significantly lower in EH as compared to C (11.22 +/- 1.37 pmol/10(9) platelets; P < .01). In addition, we investigated the stimulatory effect on cAMP of the stable PGI2 analog iloprost (10(-9), 5 x 10(-9), 10(-8), 5 x 10(-8) mol/L) in the platelets of 12 control subjects (C12) and EH.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000378:metabolism*; D000242:Cyclic AMP / Q000097:blood*; D006152:Cyclic GMP / Q000097:blood*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood*; D016285:Iloprost / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D012016:Reference Values
chemical_list: D000242:Cyclic AMP; D006152:Cyclic GMP; D016285:Iloprost