TY - JOUR
T1 - 20-HETE requires increased vascular tone to constrict rabbit afferent arterioles
AU - Arima, Shuji
AU - Omata, Ken
AU - Ito, Sadayoshi
AU - Tsunoda, Kazuo
AU - Abe, Keishi
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 1996/3
Y1 - 1996/3
N2 - Renal production of 20-hydroxyeicosatetraenoic acid (20-HETE), a cytochrome P-450-dependent arachidonate metabolite, increases during development of hypertension in spontaneously hypertensive rats, and inhibition of its production prevents hypertension. Since 20-HETE is a potent vasoconstrictor, these findings suggest that 20-HETE may contribute to the development of hypertension by elevating renal vascular resistance. In this study we examined the direct action of 20-HETE on the afferent arteriole, a vascular segment crucial to the control of renal vascular resistance. Rabbit afferent arterioles were microperfused at 60 mm Hg in vitro, and 20-HETE was added to the lumen. Although 20-HETE (10-10 to 10-6 mol/L) had no effect on the diameter of nontreated afferent arterioles (n = 6), it caused dose-dependent constriction when vascular tone was increased with norepinephrine (0.3 μmol/L); 20-HETE at 10-6 mol/L decreased diameter by 43 ± 4% (n = 6, P < .001). This constriction was abolished by disrupting the endothelium (n = 5). Moreover, pretreatment with the cyclooxygenase inhibitor indomethacin (50 μmol/L) or the thromboxane/endoperoxide receptor antagonist SQ29548 (1 μmol/L) significantly (P < .03) attenuated 20-HETE-induced constriction: 20-HETE at 10-6 mol/L constricted norepinephrine-treated afferent arterioles by 28 ± 3% (n = 6) and 25 ± 4% (n = 5), respectively. These results demonstrate that an increase in afferent arteriolar tone is required for the vasoconstrictor action of 20-HETE, which is partly mediated by the endothelial cyclooxygenase pathway. Thus, increased production of 20-HETE in the kidney and increase in afferent arteriolar tone, both of which often precede the development of hypertension, may synergistically contribute to the development of hypertension by elevating renal vascular resistance.
AB - Renal production of 20-hydroxyeicosatetraenoic acid (20-HETE), a cytochrome P-450-dependent arachidonate metabolite, increases during development of hypertension in spontaneously hypertensive rats, and inhibition of its production prevents hypertension. Since 20-HETE is a potent vasoconstrictor, these findings suggest that 20-HETE may contribute to the development of hypertension by elevating renal vascular resistance. In this study we examined the direct action of 20-HETE on the afferent arteriole, a vascular segment crucial to the control of renal vascular resistance. Rabbit afferent arterioles were microperfused at 60 mm Hg in vitro, and 20-HETE was added to the lumen. Although 20-HETE (10-10 to 10-6 mol/L) had no effect on the diameter of nontreated afferent arterioles (n = 6), it caused dose-dependent constriction when vascular tone was increased with norepinephrine (0.3 μmol/L); 20-HETE at 10-6 mol/L decreased diameter by 43 ± 4% (n = 6, P < .001). This constriction was abolished by disrupting the endothelium (n = 5). Moreover, pretreatment with the cyclooxygenase inhibitor indomethacin (50 μmol/L) or the thromboxane/endoperoxide receptor antagonist SQ29548 (1 μmol/L) significantly (P < .03) attenuated 20-HETE-induced constriction: 20-HETE at 10-6 mol/L constricted norepinephrine-treated afferent arterioles by 28 ± 3% (n = 6) and 25 ± 4% (n = 5), respectively. These results demonstrate that an increase in afferent arteriolar tone is required for the vasoconstrictor action of 20-HETE, which is partly mediated by the endothelial cyclooxygenase pathway. Thus, increased production of 20-HETE in the kidney and increase in afferent arteriolar tone, both of which often precede the development of hypertension, may synergistically contribute to the development of hypertension by elevating renal vascular resistance.
KW - arachidonic acid
KW - cytochrome P-450
KW - endothelium
KW - microcirculation
KW - prostaglandin-endoperoxide synthase
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U2 - 10.1161/01.hyp.27.3.781
DO - 10.1161/01.hyp.27.3.781
M3 - Article
C2 - 8613240
AN - SCOPUS:0029866052
VL - 27
SP - 781
EP - 785
JO - Hypertension
JF - Hypertension
SN - 0194-911X
IS - 3 II
ER -