Is low urinary prostaglandin concentration a stage in the development of essential hypertension?

Urinary prostaglandin E and F (PGE and PGF) concentrations, renal plasma flow (RPF), glomerular filtration rate (GFR), sodium excretion rate (UNaV), potassium excretion rate (UKV), urinary osmolarity (Uosm) and osmolar clearance (Cosm) were found to be higher, while mean blood pressure (MBP) was lower in a group of 15 normotensive subjects (15NS), compared to those values obtained in a group of 25 essential patients (25EHP) of the same mean age. After volume expansion, of the 25EHP, urinary PGE concentration, RPF, noncortical plasma flow (NCPF), UNaV, UKV, UNaV/UKV, Cosm and urine volume (UV) increased significantly, MBP, GFR, Uosm, free water reabsorption (Tc water) and urinary aldosterone concentration did not change, while plasma renin activity (PRA) decreased significantly. It was concluded that the deficiency in renomedullary PG synthesis in the EHP is accompanied by a decrease in RPF, NCPF and UNaV.