Involvement of cytochrome P-450 1B1 in renal dysfunction, injury, and inflammation associated with angiotensin II-induced hypertension in rats

We investigated the contribution of cytochrome P-450 1B1 (CYP1B1) to renal dysfunction and organ damage associated with ANG II-induced hypertension in rats. ANG II (300 ng·kg−1·min−1) or vehicle were infused for 2 wk, with daily injections of a selective CYP1B1 inhibitor, 2,4,3′,5′-tetramethoxystilbene (TMS; 300 μg/kg ip), or its vehicle. ANG II increased blood pressure and renal CYP1B1 activity that were prevented by TMS. ANG II also increased water intake and urine output, decreased glomerular filtration rate, increased urinary Na+ and K+ excretion, and caused proteinuria, all of which were prevented by TMS. ANG II infusion caused hypertrophy, endothelial dysfunction, and increased reactivity of renal and interlobar arteries to vasoconstrictor agents and renal vascular resistance and interstitial fibrosis as indicated by accumulation of α-smooth muscle actin, fibronectin, and collagen, and inflammation as indicated by increased infiltration of CD-3+ cells; these effects were inhibited by TMS. ANG II infusion also increased production of reactive oxygen species (ROS) and activities of NADPH oxidase, ERK1/2, p38 MAPK, and c-Src that were prevented by TMS. TMS alone had no effect on any of the above parameters. These data suggest that CYP1B1 contributes to the renal pathophysiological changes associated with ANG II-induced hypertension, most likely via increased ROS production and activation of ERK1/2, p38 MAPK, and c-Src and that CYP1B1 could serve as a novel target for treating renal disease associated with hypertension.

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Disruption of the cytochrome P-450 1B1 gene exacerbates renal dysfunction and damage associated with angiotensin II-induced hypertension in female mice

AJP Renal Physiology ◽

10.1152/ajprenal.00597.2014 ◽

2015 ◽

Vol 308 (9) ◽

pp. F981-F992 ◽

Cited By ~ 7

Author(s):

Brett L. Jennings ◽

Joseph A. Moore ◽

Ajeeth K. Pingili ◽

Anne M. Estes ◽

Xiao R. Fang ◽

...

Keyword(s):

Urinary Excretion ◽

Renal Dysfunction ◽

Urine Output ◽

Organ Damage ◽

Antioxidant Systems ◽

Ang Ii ◽

Female Mice ◽

Induced Hypertension ◽

17Β Estradiol ◽

Cytochrome P 450

Recently, we demonstrated in female mice that protection against ANG II-induced hypertension and associated cardiovascular changes depend on cytochrome P-450 (CYP)1B1. The present study was conducted to determine if Cyp1b1 gene disruption ameliorates renal dysfunction and organ damage associated with ANG II-induced hypertension in female mice. ANG II (700 ng·kg−1·min−1) infused by miniosmotic pumps for 2 wk in female Cyp1b1+/+ mice did not alter water consumption, urine output, Na+ excretion, osmolality, or protein excretion. However, in Cyp1b1−/− mice, ANG II infusion significantly increased ( P < 0.05) water intake (5.50 ± 0.42 ml/24 h with vehicle vs. 8.80 ± 0.60 ml/24 h with ANG II), urine output (1.44 ± 0.37 ml/24 h with vehicle vs. 4.30 ± 0.37 ml/24 h with ANG II), and urinary Na+ excretion (0.031 ± 0.016 mmol/24 h with vehicle vs. 0.099 ± 0.010 mmol/24 h with ANG II), decreased osmolality (2,630 ± 79 mosM/kg with vehicle vs. 1,280 ± 205 mosM/kg with ANG II), and caused proteinuria (2.60 ± 0.30 mg/24 h with vehicle vs. 6.96 ± 0.55 mg/24 h with ANG II). Infusion of ANG II caused renal fibrosis, as indicated by an accumulation of renal interstitial α-smooth muscle actin, collagen, and transforming growth factor-β in Cyp1b1−/− but not Cyp1b1+/+ mice. ANG II also increased renal production of ROS and urinary excretion of thiobarburic acid-reactive substances and reduced the activity of antioxidants and urinary excretion of nitrite/nitrate and the 17β-estradiol metabolite 2-methoxyestradiol in Cyp1b1−/− but not Cyp1b1+/+ mice. These data suggest that Cyp1b1 plays a critical role in female mice in protecting against renal dysfunction and end-organ damage associated with ANG II-induced hypertension, in preventing oxidative stress, and in increasing activity of antioxidant systems, most likely via generation of 2-methoxyestradiol from 17β-estradiol.

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Abstract 155: Group IV Cytosolic Phospholipase A 2 a Disruption Protects Against Angiotensin II-Induced Hypertension and End Organ Damage

Hypertension ◽

10.1161/hyp.62.suppl_1.a155 ◽

2013 ◽

Vol 62 (suppl_1) ◽

Author(s):

Nayaab S Khan ◽

Chi Young Song ◽

Joseph V Bonventre ◽

Kafait U Malik

Keyword(s):

Renal Dysfunction ◽

Water Intake ◽

Urine Output ◽

Organ Damage ◽

Group Iv ◽

Phospholipase A ◽

Ang Ii ◽

End Organ Damage ◽

Cytosolic Phospholipase ◽

Induced Hypertension

Previously we have shown that Group IV cytosolic phospholipase A 2 α (cPLA 2 α) is critical for the development of angiotensin (Ang) II-induced hypertension, cardiovascular dysfunction and fibrosis. This study was conducted to determine the role of cPLA 2 α in renal dysfunction and end organ damage associated with Ang II-induced hypertension. Eight weeks old male wild type (cPLA 2 α +/+ ) and cPLA 2 α knockout (cPLA 2 α -/- ) mice were infused with Ang II (700 ng/kg/min) or its vehicle for 2 weeks and systolic blood pressure (SBP) was measured weekly by the tail cuff method. Ang II increased SBP (mmHg) in cPLA 2 α +/+ mice to a greater degree than in cPLA 2 α -/- mice (125 ± 2 to 186 ± 7 vs. 125 ± 2 to 132 ± 2 respectively, P< 0.05). Ang II caused renal fibrosis as indicated by accumulation of α-smooth muscle actin, transforming growth factor-β-positive cells and collagen deposition in the kidneys of cPLA 2 α +/+ but not cPLA 2 α -/- mice. Ang II infusion increased reactive oxygen species production in the kidney measured by 2-hydroxyethidium fluorescence (AU), in cPLA 2 α +/+ mice (16.14 ± 0.61 vehicle vs. 24.08 ± 0.61 Ang II P < 0.05) but not in cPLA 2 α -/- mice (16.93 ± 0.58 vehicle vs. 17.19 ± 0.93 Ang II). Mice were placed in metabolic cages to monitor their water intake and urine output. After 13 days of Ang II infusion, 24 hr water intake was increased (4.33 ± 0.14 ml to 8.17 ± 0.27 ml P < 0.05) in cPLA 2 α +/+ mice but not in cPLA 2 α -/- mice (4.87 ± 0.22 ml to 4.8 ± 0.27 ml). Twenty-four hr urine output (μl) was increased to a greater extent in cPLA 2 α +/+ mice (423.33 ± 67.26 to 2030.94 ± 191.58 P < 0.05) vs. cPLA 2 α -/- mice (374.37 ± 66.89 to 787.37 ± 126.50). Urine osmolality (mOsm/kg) was decreased (3778.33 ± 240.21 to 1620 ± 129.23 P < 0.05) in cPLA 2 α +/+ but not in cPLA 2 α -/- mice (4042 ± 306.07 to 3372.5 ± 43.27), and proteinuria (mg/24hr) increased to a greater extent in cPLA 2 α +/+ mice (2.07 ± 0.11 to 6.99 ± 0.34 P < 0.05) vs. cPLA 2 α -/- mice (1.95 ± 0.07 to 3.03 ± 0.20 in cPLA 2 α -/- ). These data suggest that cPLA 2 α contributes to Ang II-induced hypertension, associated renal dysfunction and end organ damage, most likely due to release of arachidonic acid, activation of NADPH oxidase and generation of ROS. Thus, cPLA 2 α could serve as a potential therapeutic target in the treatment of hypertension and end organ damage.

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Abstract P135: 2-methoxyestradiol Minimizes Angiotensin II-induced Hypertension and Renal Dysfunction in Ovariectomized Female and Intact Male Mice

Hypertension ◽

10.1161/hyp.68.suppl_1.p135 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Ajeeth K Pingili ◽

Shyamala Thirunavukkarasu ◽

Nayaab S Khan ◽

Akemi Katsurada ◽

Dewan S Majid ◽

...

Keyword(s):

Angiotensin Ii ◽

Renal Dysfunction ◽

Organ Damage ◽

Ang Ii ◽

Male Mice ◽

Intact Male ◽

Female Mice ◽

End Organ Damage ◽

Induced Hypertension ◽

Post Menopausal

Men and post-menopausal females are more prone to develop hypertension and renal dysfunction as compared to pre-menopausal females. It is well documented that in various experimental models of hypertension, the protection against hypertension in females is lost following ovariectomy (OVX). Recently we have shown that CYP1B1 protects against angiotensin II (Ang II)-induced hypertension and associated cardiovascular changes in female mice, most likely via production of 2-methoxyestradiol (2-ME). This study was conducted to determine if 2-ME reduces Ang II-induced hypertension, renal dysfunction and end organ damage in OVX female, and intact male mice. Treatment of OVX Cyp1b1 +/+ and Cyp1b1 -/- female mice with 2-ME (1.5 mg/kg/day i.p., for 2 weeks) reduced Ang II-induced increase in systolic blood pressure (SBP) (182±5.1 vs. 143± 2.4 mmHg, 179±6.4 vs. 140± 8.6 mmHg, P < 0.05, n= 5), water consumption, urine output and osmolality, and proteinuria (5.5±0.7 vs. 3.3±0.5 mg/24 hrs, 8.4±1.3 vs. 4.4 ±0.9 mg/24 hrs) respectively. 2-ME also reduced Ang II-induced increase in SBP (188±2.6 vs. 143± 2.7 mmHg, P < 0.05, n= 5) in intact male mice. 2-ME did not alter water consumption and urine osmolality, but reduced urine output and sodium excretion, and proteinuria (14.4±2.0 vs. 6.0±0.5 mg/24 hrs) in intact Cyp1b1 +/+ male mice. Treatment with 2-ME attenuated Ang II-induced end-organ damage (actin and collagen accumulation) in OVX Cyp1b1 +/+ and Cyp1b1 -/- female and Cyp1b1 +/+ male mice. 2-ME mitigated urinary excretion of angiotensinogen in OVX Cyp1b1 +/+ and Cyp1b1 -/- female mice infused with Ang II. These data suggest that 2-ME reduces Ang II- induced hypertension and associated renal dysfunction and end-organ damage in OVX Cyp1b1 +/+ and Cyp1b1 -/- female, and intact male mice. Therefore, 2-ME could serve as a therapeutic agent for treatment of hypertension and associated pathogenesis in post-menopausal females, and intact males.

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2,3′,4,5′-Tetramethoxystilbene prevents deoxycorticosterone-salt-induced hypertension: contribution of cytochrome P-450 1B1

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00655.2010 ◽

2010 ◽

Vol 299 (6) ◽

pp. H1891-H1901 ◽

Cited By ~ 26

Author(s):

Seyhan Sahan-Firat ◽

Brett L. Jennings ◽

Fariborz A. Yaghini ◽

Chi Young Song ◽

Anne M. Estes ◽

...

Keyword(s):

P38 Mapk ◽

Vascular Reactivity ◽

Urine Osmolality ◽

Oxygen Species ◽

Salt Treatment ◽

Mapk Activity ◽

Kidney Hypertrophy ◽

Induced Hypertension ◽

Novel Target ◽

Cytochrome P 450

Reactive oxygen species (ROS) contribute to various models of hypertension, including deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Recently, we have shown that ROS, generated by cytochrome P-450 1B1 (CYP1B1) from arachidonic acid, mediate vascular smooth muscle cell growth caused by angiotensin II. This study was conducted to determine the contribution of CYP1B1 to hypertension and associated pathophysiological changes produced by DOCA (30 mg/kg) given subcutaneously per week with 1% NaCl + 0.1% KCl in drinking water to uninephrectomized rats for 6 wk. DOCA-salt treatment increased systolic blood pressure (SBP). Injections of the selective inhibitor of CYP1B1, 2,3′,4,5′-tetramethoxystilbene (TMS; 300 μg/kg ip every 3rd day) initiated at the 4th week of DOCA-salt treatment normalized SBP and decreased CYP1B1 activity but not its expression in the aorta, heart, and kidney. TMS also inhibited cardiovascular and kidney hypertrophy, prevented the increase in vascular reactivity and endothelial dysfunction, and minimized the increase in urinary protein and K+ output and the decrease in urine osmolality, Na+ output, and creatinine clearance associated with DOCA-salt treatment. These pathophysiological changes caused by DOCA-salt treatment and associated increase in vascular superoxide production, NADPH oxidase activity, and expression of NOX-1, and ERK1/2 and p38 MAPK activities in the aorta, heart, and kidney were inhibited by TMS. These data suggest that CYP1B1 contributes to DOCA-salt-induced hypertension and associated pathophysiological changes, most likely as a result of increased ROS production and ERK1/2 and p38 MAPK activity, and could serve as a novel target for the development of agents like TMS to treat hypertension.

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Abstract P231: Inhibition of Mir-762 Prevents and Reverses Ang II Induced Aortic Stiffening

Hypertension ◽

10.1161/hyp.68.suppl_1.p231 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Kim Ramil C Montaniel ◽

Jing Wu ◽

Matthew R Bersi ◽

Liang Xiao ◽

Hana A Itani ◽

...

Keyword(s):

P38 Mapk ◽

Aortic Stiffness ◽

Fold Increase ◽

Organ Damage ◽

Locked Nucleic Acid ◽

Ang Ii ◽

New Approach ◽

Acid Inhibitor ◽

Aortic Stiffening

We and others have shown that hypertension (HTN) is linked with striking fibrosis in the aortic adventitia. This leads to aortic stiffening, leading to organ damage. Through a screen of microRNAs (miRNAs) in the aorta, we found that miR-762 is the most upregulated miRNA in Ang II hypertensive mice. qRT-PCR confirmed that miR-762 is upregulated 6.35±1.22 (p=0.03) fold in Ang II-infused mice compared to controls. To study the role of miR-762 in HTN, we administered a locked nucleic acid inhibitor of miR-762. MiR-762 inhibition normalized stress-strain relationships and aortic systolic energy storage (ASE) (Table). Moreover, miR-762 inhibition in the last 2 weeks of Ang II infusion reversed aortic stiffness in mice treated with 4 wk of Ang II (ASE, 4 wk Ang II [51±5.18 kPa] vs 4wk Ang II + LNA-762 (last 2 wk) [20±1.76 kPa], p<0.0001). Further studies showed that miR-762 inhibition reduced mRNA for several collagens and fibronectin and upregulated collagenases MMP1a, 8 and 13 (Table). Lastly, we found that miR-762 inhibition during Ang II infusion led to a 9.11±1.92 (p=0.007) fold increase in Sprouty1 mRNA, suggesting that miR-762 targets Sprouty1 mRNA. Sprouty1 inhibits the activation of p38-MAPK which is critical in the process of aortic stiffening. Hence, miR-762 modulates aortic stiffening and fibrosis through a Sprouty1-p38-MAPK mechanism. Thus, miR-762 has a major role in modulating aortic stiffening and its inhibition dramatically inhibits pathological fibrosis, enhances matrix degradation, prevents and reverses aortic stiffness. miR-762 inhibition might represent a new approach to prevent aortic stiffening and its consequent end-organ damage.

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Abstract 252: 6ß-Hydroxytestosterone, A Cytochrome P450 1B1 Metabolite of Testosterone, Enhances Angiotensin II-Induced Pressor Effect in Male Mice

Hypertension ◽

10.1161/hyp.62.suppl_1.a252 ◽

2013 ◽

Vol 62 (suppl_1) ◽

Author(s):

Ajeeth K Pingili ◽

Brett L Jennings ◽

Nayaab S Khan ◽

Kafait U Malik

Keyword(s):

Cytochrome P450 ◽

Endothelial Dysfunction ◽

Ros Production ◽

Oxygen Species ◽

Pressor Effect ◽

Ang Ii ◽

Male Mice ◽

Cytochrome P450 1B1 ◽

Induced Hypertension ◽

Novel Target

Androgens have been implicated in the development of hypertension and castration minimizes the pressor effect of angiotensin (Ang) II. Previously we showed that Ang II-induced hypertension and associated pathophysiological changes are diminished in male cytochrome P450 (CYP) 1B1 gene disrupted mice. Since CYP1B1 metabolizes testosterone to 6β-hydroxytestosterone (6β-OHT); this study was conducted to determine its contribution in modulation of Ang II-induced hypertension. Eight weeks old male Cyp1b1+/+ and Cyp1b1-/- mice were either castrated or injected with 6β-OHT (15 μg/g, i.p. every 3rd day) or vehicle (DMSO, 50 μl), infused with Ang II (700 ng/kg/min) or vehicle for 2 weeks, and systolic blood pressure (SBP) was measured by tail cuff. Castration attenuated Ang II-induced increase in SBP in both Cyp1b1+/+ (184 ± 6 vs. 129 ± 4 mmHg, P < 0.05) and Cyp1b1-/- mice (150 ± 6 vs. 129 ± 4 mmHg, P < 0.05). In Cyp1b1+/+ mice, 6β-OHT did not alter Ang II-induced increase in SBP (184 ± 6 vs. 180 ± 8 mmHg, P < 0.05), but enhanced it in Cyp1b1-/- mice (150 ± 6 vs. 172 ± 8 mmHg, P < 0.05). Castration improved endothelial dysfunction associated with Ang II-induced hypertension in Cyp1b1+/+ mice, as demonstrated by increased relaxation of the aorta to acetylcholine. No endothelial dysfunction was observed in Cyp1b1-/- mice given Ang II with or without castration. In Cyp1b1+/+ mice, 6β-OHT did not alter Ang II-induced endothelial dysfunction, however, in Cyp1b1-/- mice infused with Ang II, 6β-OHT caused endothelial dysfunction. We have shown that Ang II-induced hypertension is associated with increased vascular production of reactive oxygen species (ROS) in Cyp1b1+/+ mice, and this increase is attenuated in Cyp1b1-/- mice, as measured by dihydroethidium fluorescence. In both Cyp1b1+/+ and Cyp1b1-/- mice given Ang II, castration abolished the increased ROS production. In Cyp1b1+/+ mice, 6β-OHT did not alter levels of ROS produced by Ang II, however, 6β-OHT further increased ROS production in Cyp1b1-/- mice given Ang II. These data suggest that 6β-OHT, a CYP1B1 metabolite of testosterone, contributes to the hypertensive effect of Ang II in male mice. Moreover, CYP1B1 could serve as a novel target for the development of agents for the treatment of androgen-mediated hypertension.

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Angiotensin II releases 20-HETE from rat renal microvessels

AJP Renal Physiology ◽

10.1152/ajprenal.2000.279.3.f544 ◽

2000 ◽

Vol 279 (3) ◽

pp. F544-F551 ◽

Cited By ~ 102

Author(s):

Kevin D. Croft ◽

John C. McGiff ◽

Alicia Sanchez-Mendoza ◽

Mairead A. Carroll

Keyword(s):

Chemical Ionization ◽

Ang Ii ◽

Sprague Dawley ◽

The Third ◽

Sprague Dawley Rats ◽

Vascular Segment ◽

Effector Unit ◽

Gas Chromatography Mass Spectroscopy ◽

Renal Vascular ◽

Cytochrome P 450

We studied hydroxyeicosatetraenoic acid (HETE) release in response to ANG II from preglomerular microvessels (PGMVs), the vascular segment governing changes in renal vascular resistance. PGMVs were isolated from Sprague-Dawley rats and incubated with NADPH and hormones at 37°C. Eicosanoids were extracted, and cytochrome P-450 (CYP)-derived HETEs were purified and quantitated by negative chemical ionization gas chromatography-mass spectroscopy. PGMVs produced primarily 20- and 19-HETEs, namely, 7.9 ± 1.7 and 2.2 ± 0.5 ng/mg protein, respectively. ANG II (5 nM) increased CYP-HETE release by two- to threefold; bradykinin, phenylephrine, and Ca2+ionophore were without effect. [Sar1]ANG II (0.1–100 μM) dose dependently stimulated 19- and 20-HETEs, an effect blocked by the AT2-receptor antagonist PD-123319 as well as by U-73122, a phospholipase C inhibitor. Microvascular 20-HETE release was increased more than twofold by the third day in response to ANG II (120 ng · kg−1 · min−1) infused subcutaneously for 2 wk; it was not further enhanced after 14 days, although blood pressure continued to rise. Thus an AT2-phospholipse C effector unit is associated with synthesis of a vasoconstrictor product, 20-HETE, in a key renovascular segment.

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Asymmetric dimethylarginine in angiotensin II-induced hypertension

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.90875.2008 ◽

2010 ◽

Vol 298 (3) ◽

pp. R740-R746 ◽

Cited By ~ 36

Author(s):

Jennifer M. Sasser ◽

Natasha C. Moningka ◽

Mark W. Cunningham ◽

Byron Croker ◽

Chris Baylis

Keyword(s):

Nitric Oxide ◽

Renal Injury ◽

Asymmetric Dimethylarginine ◽

Renal Cortex ◽

Interstitial Fibrosis ◽

Glomerular Sclerosis ◽

Ang Ii ◽

Sprague Dawley ◽

Plasma Adma ◽

Induced Hypertension

Recent studies have shown that asymmetric dimethylarginine (ADMA), a nitric oxide synthase inhibitor, is increased in hypertension and chronic kidney disease. However, little is known about the effects of hypertension per se on ADMA metabolism. The purpose of this study was to test the hypothesis that ANG II-induced hypertension, in the absence of renal injury, is associated with increased oxidative stress and plasma and renal cortex ADMA levels in rats. Male Sprague-Dawley rats were treated with ANG II at 200 ng·kg−1·min−1 sc (by minipump) for 1 or 3 wk or at 400 ng·kg−1·min−1 for 6 wk. Mean arterial pressure was increased after 3 and 6 wk of ANG II; however, renal injury (proteinuria, glomerular sclerosis, and interstitial fibrosis) was only evident after 6 wk of treatment. Plasma thiobarbituric acid reactive substances concentration and renal cortex p22phox protein abundance were increased early (1 and 3 wk), but urinary excretion of isoprostane and H2O2 was only increased after 6 wk of ANG II. An increased in plasma ADMA after 6 wk of ANG II was associated with increased lung protein arginine methyltransferase-1 abundance and decreased renal cortex dimethylarginine dimethylaminohydrolase activity. No changes in renal cortex ADMA were observed. ANG II hypertension in the absence of renal injury is not associated with increased ADMA; however, when the severity and duration of the treatment were increased, plasma ADMA increased. These data suggest that elevated blood pressure alone, for up to 3 wk, in the absence of renal injury does not play an important role in the regulation of ADMA. However, the presence of renal injury and sustained hypertension for 6 wk increases ADMA levels and contributes to nitric oxide deficiency and cardiovascular disease.

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Abstract 250: 6β-hydroxytestosterone, A Cytochrome P450 1b1-derived Metabolite Of Testosterone, Mediates Increase In Thirst, Renal Dysfunction, And End Organ Damage Associated With Angiotensin II-induced Hypertension In Male Mice

Hypertension ◽

10.1161/hyp.64.suppl_1.250 ◽

2014 ◽

Vol 64 (suppl_1) ◽

Author(s):

Ajeeth K Pingili ◽

Mehmet Kara ◽

Brett L Jennings ◽

Anne M Estes ◽

Kafait U Malik

Keyword(s):

Oxidative Stress ◽

Renal Function ◽

Cytochrome P450 ◽

Renal Fibrosis ◽

Organ Damage ◽

Ang Ii ◽

Male Mice ◽

End Organ Damage ◽

Cytochrome P450 1B1 ◽

Induced Hypertension

Recently, we showed that 6β-hydroxytestosterone (6β-OHT), a cytochrome P450 1B1 (CYP1B1)-derived metabolite of testosterone, contributes to the development of angiotensin II (Ang II)-induced hypertension and associated cardiovascular pathophysiology. In view of the critical role of Ang II in renal homeostasis and end organ damage, we determined the contribution of 6β-OHT to Ang II actions on water consumption and renal function in male Cyp1b1 +/+ and Cyp1b1 -/- mice. Eight weeks old male Cyp1b1 +/+ and Cyp1b1 -/- intact or castrated mice were injected with 6β-OHT (15 μg/g, i.p. every 3 rd day) or vehicle (DMSO, 50 μl), and infused with Ang II (700 ng/kg/min) or vehicle for 2 weeks. Urine was collected for 24 hours on the final day of experiment. Castration attenuated Ang II-induced increase in water consumption and urine output, proteinuria and decrease in osmolality in both Cyp1b1 +/+ , and Cyp1b1 -/- mice (Table 1). 6β-OHT did not alter Ang II-induced increase in water intake, urine output, proteinuria and decrease in osmolality in Cyp1b1 +/+ mice, but restored these effects of Ang II in Cyp1b1 -/- or castrated mice (Table 1). Cyp1b1 gene disruption or castration prevented Ang II-induced renal fibrosis, inflammation, and oxidative stress. 6β-OHT did not alter Ang II-induced renal fibrosis, inflammation or oxidative stress in Cyp1b1 +/+ mice, however in Cyp1b1 -/- or castrated mice it restored these effects of Ang II. These data suggest that 6β-OHT, contributes to increased thirst, impairment of renal function and end organ damage associated with Ang II-induced hypertension in male mice, and that CYP1B1 could serve as a novel target for the treatment of renal disease and hypertension.

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