Renal nerves contribute to hypertension in Schlager BPH/2J mice
- Gueguen, Cindy, Jackson, Kristy, Marques, Francine, Eikelis, Nina, Phillips, Sarah, Stevenson, Emily, Charchar, Fadi, Lambert, Gavin, Davern, Pamela, Head, Geoffrey
- Authors: Gueguen, Cindy , Jackson, Kristy , Marques, Francine , Eikelis, Nina , Phillips, Sarah , Stevenson, Emily , Charchar, Fadi , Lambert, Gavin , Davern, Pamela , Head, Geoffrey
- Date: 2019
- Type: Text , Journal article
- Relation: Hypertension Research Vol. 42, no. 3 (2019), p. 306-318
- Full Text:
- Reviewed:
- Description: Schlager mice (BPH/2J) are hypertensive due to a greater contribution of the sympathetic nervous system (SNS) and renin-angiotensin system (RAS). The kidneys of BPH/2J are hyper-innervated suggesting renal nerves may contribute to the hypertension. We therefore determined the effect of bilateral renal denervation (RD) on hypertension in BPH/2J. Mean arterial pressure (MAP) was measured by radiotelemetry before and for 3 weeks after RD in BPH/2J and BPN/3J. The effects of pentolinium and enalaprilat were examined to determine the contribution of the SNS and RAS, respectively. After 3 weeks, MAP was −10.9 ± 2.1 mmHg lower in RD BPH/2J compared to baseline and −2.1 ± 2.2 mmHg in sham BPH/2J (P < 0.001, n = 8–10). RD had no effect in BPN/3J (P > 0.1). The depressor response to pentolinium was greater in BPH/2J than BPN/3J, but in both cases the response in RD mice was similar to sham. Enalaprilat decreased MAP more in RD BPH/2J compared to sham (−12 vs −3 mmHg, P < 0.001) but had no effect in BPN/3J. RD reduced renal noradrenaline in both strains but more so in BPH/2J. RD reduced renin mRNA and protein, but not plasma renin in BPH/2J to levels comparable with BPN/3J mice. We conclude that renal nerves contribute to hypertension in BPH mice as RD induced a sustained fall in MAP, which was associated with a reduction of intrarenal renin expression. The lack of inhibition of the depressor effects of pentolinium and enalaprilat by RD suggests that vasoconstrictor effects of the SNS or RAS are not involved.
- Authors: Gueguen, Cindy , Jackson, Kristy , Marques, Francine , Eikelis, Nina , Phillips, Sarah , Stevenson, Emily , Charchar, Fadi , Lambert, Gavin , Davern, Pamela , Head, Geoffrey
- Date: 2019
- Type: Text , Journal article
- Relation: Hypertension Research Vol. 42, no. 3 (2019), p. 306-318
- Full Text:
- Reviewed:
- Description: Schlager mice (BPH/2J) are hypertensive due to a greater contribution of the sympathetic nervous system (SNS) and renin-angiotensin system (RAS). The kidneys of BPH/2J are hyper-innervated suggesting renal nerves may contribute to the hypertension. We therefore determined the effect of bilateral renal denervation (RD) on hypertension in BPH/2J. Mean arterial pressure (MAP) was measured by radiotelemetry before and for 3 weeks after RD in BPH/2J and BPN/3J. The effects of pentolinium and enalaprilat were examined to determine the contribution of the SNS and RAS, respectively. After 3 weeks, MAP was −10.9 ± 2.1 mmHg lower in RD BPH/2J compared to baseline and −2.1 ± 2.2 mmHg in sham BPH/2J (P < 0.001, n = 8–10). RD had no effect in BPN/3J (P > 0.1). The depressor response to pentolinium was greater in BPH/2J than BPN/3J, but in both cases the response in RD mice was similar to sham. Enalaprilat decreased MAP more in RD BPH/2J compared to sham (−12 vs −3 mmHg, P < 0.001) but had no effect in BPN/3J. RD reduced renal noradrenaline in both strains but more so in BPH/2J. RD reduced renin mRNA and protein, but not plasma renin in BPH/2J to levels comparable with BPN/3J mice. We conclude that renal nerves contribute to hypertension in BPH mice as RD induced a sustained fall in MAP, which was associated with a reduction of intrarenal renin expression. The lack of inhibition of the depressor effects of pentolinium and enalaprilat by RD suggests that vasoconstrictor effects of the SNS or RAS are not involved.
Tripartite motif-containing 55 identified as functional candidate for spontaneous cardiac hypertrophy in the rat locus cardiac mass 22
- Prestes, Priscilla, Marques, Francine, Lopez-Campos, Guillermo, Booth, Scott, McGlynn, Maree, Lewandowski, Paul, Delbridge, Lea, Harrap, Stephen, Charchar, Fadi
- Authors: Prestes, Priscilla , Marques, Francine , Lopez-Campos, Guillermo , Booth, Scott , McGlynn, Maree , Lewandowski, Paul , Delbridge, Lea , Harrap, Stephen , Charchar, Fadi
- Date: 2016
- Type: Text , Journal article
- Relation: Journal of Hypertension Vol. 34, no. 5 (May 2016), p. 950-958
- Relation: http://purl.org/au-research/grants/nhmrc/1034371
- Full Text:
- Reviewed:
- Description: Background:Left ventricular (LV) hypertrophy is a risk factor for cardiovascular death, but the genetic factors determining LV size and predisposition to hypertrophy are not well understood. We have previously linked the quantitative trait locus cardiac mass 22 (Cm22) on chromosome 2 with cardiac hypertrophy independent of blood pressure in the spontaneously hypertensive rat. From an original cross of spontaneously hypertensive rat with F344 rats, we derived a normotensive polygenic model of spontaneous cardiac hypertrophy, the hypertrophic heart rat (HHR) and its control strain, the normal heart rat (NHR).Methods and results:To identify the genes and molecular mechanisms underlying spontaneous LV hypertrophy we sequenced the HHR genome with special focus on quantitative trait locus Cm22. For correlative analyses of function, we measured global RNA transcripts in LV of neonatal HHR and NHR and 198 neonatal rats of an HHRxNHR F2 crossbred population. Only one gene within locus Cm22 was differentially expressed in the parental generation: tripartite motif-containing 55 (Trim55), with mRNA downregulation in HHR (P<0.05) and reduced protein expression. Trim55 mRNA levels were negatively correlated with LV mass in the F2 cross (r=-0.16, P=0.025). In exon nine of Trim55 in HHR, we found one missense mutation that functionally alters protein structure. This mutation was strongly associated with Trim55 mRNA expression in F2 rats (F=10.35, P<0.0001). Similarly, in humans, we found reduced Trim55 expression in hearts of subjects with idiopathic dilated cardiomyopathy.Conclusion:Our study suggests that the Trim55 gene, located in Cm22, is a novel candidate gene for polygenic LV hypertrophy independent of blood pressure.
- Authors: Prestes, Priscilla , Marques, Francine , Lopez-Campos, Guillermo , Booth, Scott , McGlynn, Maree , Lewandowski, Paul , Delbridge, Lea , Harrap, Stephen , Charchar, Fadi
- Date: 2016
- Type: Text , Journal article
- Relation: Journal of Hypertension Vol. 34, no. 5 (May 2016), p. 950-958
- Relation: http://purl.org/au-research/grants/nhmrc/1034371
- Full Text:
- Reviewed:
- Description: Background:Left ventricular (LV) hypertrophy is a risk factor for cardiovascular death, but the genetic factors determining LV size and predisposition to hypertrophy are not well understood. We have previously linked the quantitative trait locus cardiac mass 22 (Cm22) on chromosome 2 with cardiac hypertrophy independent of blood pressure in the spontaneously hypertensive rat. From an original cross of spontaneously hypertensive rat with F344 rats, we derived a normotensive polygenic model of spontaneous cardiac hypertrophy, the hypertrophic heart rat (HHR) and its control strain, the normal heart rat (NHR).Methods and results:To identify the genes and molecular mechanisms underlying spontaneous LV hypertrophy we sequenced the HHR genome with special focus on quantitative trait locus Cm22. For correlative analyses of function, we measured global RNA transcripts in LV of neonatal HHR and NHR and 198 neonatal rats of an HHRxNHR F2 crossbred population. Only one gene within locus Cm22 was differentially expressed in the parental generation: tripartite motif-containing 55 (Trim55), with mRNA downregulation in HHR (P<0.05) and reduced protein expression. Trim55 mRNA levels were negatively correlated with LV mass in the F2 cross (r=-0.16, P=0.025). In exon nine of Trim55 in HHR, we found one missense mutation that functionally alters protein structure. This mutation was strongly associated with Trim55 mRNA expression in F2 rats (F=10.35, P<0.0001). Similarly, in humans, we found reduced Trim55 expression in hearts of subjects with idiopathic dilated cardiomyopathy.Conclusion:Our study suggests that the Trim55 gene, located in Cm22, is a novel candidate gene for polygenic LV hypertrophy independent of blood pressure.
- «
- ‹
- 1
- ›
- »