TY - JOUR
T1 - The role of 20-hydroxyeicosatetraenoic acid in adrenocorticotrophic hormone and dexamethasone-induced hypertension
AU - Zhang, Yi
AU - Wu, Jason H.Y.
AU - Vickers, Janine J.
AU - Ong, Sharon L.H.
AU - Temple, Suzanna E.L.
AU - Mori, Trevor A.
AU - Croft, Kevin D.
AU - Whitworth, Judith A.
PY - 2009/8
Y1 - 2009/8
N2 - OBJECTIVE: 20-hydroxyeicosatetraenoic acid (20-HETE) is a potent constrictor in small arteries and also has natriuretic properties. Urinary 20-HETE excretion is increased in adrenocorticotrophic hormone (ACTH)-induced hypertensive rats. In the present study, we investigated the effect of a specific enzyme inhibitor of 20-HETE production, N-hydroxy-N′-(4-butyl-2- methylphenyl) formamidine (HET0016), on glucocorticoid-induced hypertension in rats, a sodium-independent model. METHODS: Male Sprague-Dawley rats were treated with physiological saline (0.9% NaCl), ACTH (0.2 mg/kg per day) or dexamethasone (0.03 mg/rat per day) subcutaneously for 13 days. HET0016 (10 mg/kg per day) or its vehicle (10% lecithin in physiological saline) was coadministered (intraperitoneally) a day before (prevention study) or at day 8 of treatment (reversal studies). Systolic blood pressure was measured by the tail-cuff method. RESULTS: Relative to physiological saline, systolic blood pressure was increased by ACTH (P < 0.001) and dexamethasone (P < 0.01). HET0016 reversed ACTH-induced (P < 0.01) but not dexamethasone-induced hypertension. HET0016 also prevented the development of hypertension induced by ACTH (P < 0.01). ACTH, but not dexamethasone, increased renal microsome 20-HETE formation and plasma F2-isoprostane concentrations. HET0016 inhibited renal 20-HETE formation but had no effect on plasma F2-isoprostane concentrations or renal cytochrome P450 4A1 expression. CONCLUSION: Inhibition of 20-HETE production by HET0016 prevents and reverses ACTH-induced but not dexamethasone-induced hypertension. These results suggest that 20-HETE may play a role in the genesis of ACTH-induced hypertension but not in dexamethasone-induced hypertension.
AB - OBJECTIVE: 20-hydroxyeicosatetraenoic acid (20-HETE) is a potent constrictor in small arteries and also has natriuretic properties. Urinary 20-HETE excretion is increased in adrenocorticotrophic hormone (ACTH)-induced hypertensive rats. In the present study, we investigated the effect of a specific enzyme inhibitor of 20-HETE production, N-hydroxy-N′-(4-butyl-2- methylphenyl) formamidine (HET0016), on glucocorticoid-induced hypertension in rats, a sodium-independent model. METHODS: Male Sprague-Dawley rats were treated with physiological saline (0.9% NaCl), ACTH (0.2 mg/kg per day) or dexamethasone (0.03 mg/rat per day) subcutaneously for 13 days. HET0016 (10 mg/kg per day) or its vehicle (10% lecithin in physiological saline) was coadministered (intraperitoneally) a day before (prevention study) or at day 8 of treatment (reversal studies). Systolic blood pressure was measured by the tail-cuff method. RESULTS: Relative to physiological saline, systolic blood pressure was increased by ACTH (P < 0.001) and dexamethasone (P < 0.01). HET0016 reversed ACTH-induced (P < 0.01) but not dexamethasone-induced hypertension. HET0016 also prevented the development of hypertension induced by ACTH (P < 0.01). ACTH, but not dexamethasone, increased renal microsome 20-HETE formation and plasma F2-isoprostane concentrations. HET0016 inhibited renal 20-HETE formation but had no effect on plasma F2-isoprostane concentrations or renal cytochrome P450 4A1 expression. CONCLUSION: Inhibition of 20-HETE production by HET0016 prevents and reverses ACTH-induced but not dexamethasone-induced hypertension. These results suggest that 20-HETE may play a role in the genesis of ACTH-induced hypertension but not in dexamethasone-induced hypertension.
KW - 20-hydroxyeicosatetraenoic acid
KW - Arachidonic acid
KW - Glucocorticoid
KW - Hypertension
KW - N-hydroxy-N0-(4-butyl-2-methylphenyl) formamidine
UR - http://www.scopus.com/inward/record.url?scp=68449086969&partnerID=8YFLogxK
U2 - 10.1097/HJH.0b013e32832cc56c
DO - 10.1097/HJH.0b013e32832cc56c
M3 - Article
SN - 0263-6352
VL - 27
SP - 1609
EP - 1616
JO - Journal of Hypertension
JF - Journal of Hypertension
IS - 8
ER -