[Urinary thromboxane B2 in hypertensive patients].
Thromboxane A2 (TxA2) is a vasoconstrictor synthetized by the kidney. Its role in hypertension is unknown. We measured urinary TxB2 (the metabolite of renal TxA2) by radioimmunoassay and studied renal functions in 15 borderline, 15 sustained essential hypertensive patients and 12 age-matched normotensive subjects (6 young and 6 older adults). Results were as follows: Normotensive subjects: Mean arterial blood pressure (MBP) 97 +/- 2 mmHg, urinary TxB2 (UTxB2V) 159 +/- 12 pg/min, glomerular filtration rate (GFR) 120 +/- 8 ml/min, sodium excretion (UNaV) 73 +/- 9 mueq/min. Hypertensive patients: MBP 115 +/- 2 mmHg (p less than 0,001 vs controls), UTxB2V 298 +/- 24 pg/min (p less than 0,005), GFR 128 +/- 6 ml/min, UNaV 51 +/- 4 mueq/min (p less than 0.02). There was a positive significant correlation between UTxB2V and GFR (p less than 0,005) and between UTxB2V and UNaV (p less than 0,005) in hypertensive but not in normotensive subjects. There was no correlation between GFR and UNaV in either group.


CONCLUSIONS
1. Urinary (i.e. renal) TxB2 is significantly elevated in hypertensive patients; 2. TxA2 may be a mediator of pressure natriuresis.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure; D005919:Glomerular Filtration Rate; D006801:Humans; D006973:Hypertension / Q000503:physiopathology / Q000652:urine*; D007668:Kidney / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009318:Natriuresis; D013928:Thromboxane A2 / Q000378:metabolism; D013929:Thromboxane B2 / Q000652:urine*; D013931:Thromboxanes / Q000652:urine*
D013931:Thromboxanes; D013929:Thromboxane B2; D013928:Thromboxane A2
Thromboxane B2 urinaire chez les malades hypertendus.