Enhanced urinary excretion of cGMP in liver cirrhosis. Relationship to hemodynamic changes, neurohormonal activation, and urinary sodium excretion

Abstract

Cyclic guanosine monophosphate (cGMP) has been proposed to mediate peripheral arterial vasodilation in liver cirrhosis. Nitric oxide and natriuretic peptides are the main signals for cGMP generation. Variation in urinary cGMP excretion parallels changes in plasma cGMP levels. Our aim was to determine urinary excretion of cGMP (UcGMPV) and to investigate its relationship to systemic hemodynamics, neurohumoral activity and renal sodium excretion in cirrhosis. Urinary excretion of cGMP was measured in 19 healthy subjects and 20 patients with alcoholic cirrhosis. Systemic hemodynamic parameters, blood volume (BV), plasma atrial natriuretic factor (ANF), and the endothelium-dependent vasodilator substance P (SP) were determined in all patients and in five healthy subjects. Urinary cGMPV was higher in the group of patients (736 pg/min; 50-3229 pg/min) than in controls (126 pg/min; 0-1657 pg/min) (P < 0.01). In addition, UcGMPV inversely correlated with the systemic vascular resistance and directly with cardiac output, blood volume, SP, ANF, and Pugh's score. By Cox regression analysis, only systemic vascular resistance remained inversely associated with UcGMPV. In conclusion, urinary cGMP excretion is increased in cirrhosis. It is suggested that increased cGMP generation may be related to the hyperkinetic circulation in human cirrhosis.