Faculty Collaboration Database

Increased renal vascular reactivity to ANG II after unilateral nephrectomy in the rat involves 20-HETE. Am J Physiol Regul Integr Comp Physiol 2006 Oct;291(4):R977-86

Date

05/06/2006

Pubmed ID

16675634

DOI

10.1152/ajpregu.00401.2005

Scopus ID

2-s2.0-33749346983 (requires institutional sign-in at Scopus site)   28 Citations

Abstract

This study examined the role of intrarenal ANG II in the renal vascular reactivity changes occurring in the remaining kidney undergoing adaptation following contralateral nephrectomy. Renal blood flow responses to intrarenal injections of ANG II (0.25 to 5 ng) were measured in anesthetized euvolemic male Wistar rats 1, 4, 12, and 24 wk after uninephrectomy (UNX) or sham procedure (SHAM). At week 4, renal vasoconstriction induced by 2 ng ANG II was greater in UNX (69 +/- 5%) than in SHAM rats (50 +/- 3%; P < 0.01). This response was inhibited, by 50 and 66%, and by 20 and 25%, in SHAM and UNX rats, after combined injections of ANG II and losartan, or PD-123319 (P < 0.05), respectively. Characteristics of ANG II receptor binding in isolated preglomerular resistance vessels were similar in the two groups. After prostanoid inhibition with indomethacin, renal vasoconstriction was enhanced by 42 +/- 8% (P < 0.05), only in SHAM rats, whereas after 20-HETE inhibition with HET0016, it was reduced by 53 +/- 16% (P < 0.05), only in UNX rats. These differences vanished after concomitant prostanoid and 20-HETE inhibition in the two groups. After UNX, renal cortical protein expression of cytochrome P-450 2c23 isoform (CYP2c23) and cyclooxygenase-1 (COX-1) was unaltered, but it was decreased for CYP4a and increased for COX-2. In conclusion, renal vascular reactivity to ANG II was significantly increased in the postuninephrectomy adapted kidney, independently of protein expression, but presumably involving interactions between 20-HETE and COX in the renal microvasculature and changes in the paracrine activity of ANG II and 20-HETE.

Author List

Joly E, Seqqat R, Flamion B, Caron N, Michel A, Imig JD, Kramp R

MESH terms used to index this publication - Major topics in bold

Adaptation, Physiological
Amidines
Angiotensin II
Angiotensin II Type 1 Receptor Blockers
Animals
Cyclooxygenase 1
Cyclooxygenase Inhibitors
Cytochrome P-450 Enzyme System
Dinoprostone
Hydroxyeicosatetraenoic Acids
Imidazoles
Indomethacin
Losartan
Male
Microcirculation
Nephrectomy
Norepinephrine
Pyridines
Rats
Rats, Wistar
Renal Circulation
Vasoconstriction
Vasoconstrictor Agents