High Salt Intake Decreases EET Excretion in Stroke‐Prone Spontaneously Hypertensive Rats (SHRSP)

Abstract

Epoxyeicosatrienoic acids (EETs) have renal vasodilatory, natriuretic and diuretic activities. High salt intake stimulates production of EETs and diminished EETs formation may be related to the development of salt-sensitive hypertension in Dahl-S rats. We evaluated changes in EETs production in SHRSP as the development of vascular lesions is highly dependent on salt intake in these animals. Urine was collected from male Wistar-Kyoto rats (WKY) and SHRSP (Charles River, 6 week old) before (7 weeks old), and 10 days after, placement on 1% NaCl (HS) drinking solution. Urinary EETs and dihydroxyeicosatrienioc acids (DHETs), metabolites of EETs were quantitated by GCMS. Urine volume (UV) was lower and excretion of EETs+DHETs was higher in SHRSP than WKY under normal salt conditions (NS, 0.4% NaCl). WKY showed an increase in UV, but no change in EETs or DHETs excretion in response to HS intake. In contrast, excretion of EETs and DHETs was markedly decreased in SHRSP in response to HS intake. These results demonstrate a major alteration in EETs formation in response to HS intake in SHRSP. Whether this defect in EETs formation contributes to the development of pathology in SHRSP remains to be investigated.