Abstract 097: Effects of Lysine-specific Demethylase 1 Deficiency on Aldosterone Production and Salt-sensitive Hypertension in Female Mice

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Yuefei Huang ◽  
Tham M Yao ◽  
Paul Loutraris ◽  
Isis K Rangel ◽  
Pei Yee Ting ◽  
...  

Lysine-Specific Demethylase1 (LSD1) is an epigenetic factor modulated by salt intake. Previously, we documented the male heterozygote LSD1 knockout mice (LSD1+/-) had dysregulation of aldosterone (ALDO) production on a liberal salt diet (1.6% Na+) associated with salt-sensitive hypertension. This study assessed if: 1) female LSD1+/- mice have a similar phenotype; and 2) the effect of aging on this phenotype. Methods: Female LSD1+/- and wild type mice (LSD1+/+) were randomly assigned for sacrifice at the ages of 18-week, 52-week, and 75-week and the following were assessed at each time point: blood pressure (BP); plasma renin activity (PRA) and ALDO; urine albumin; and ex vivo ALDO production from isolated adrenal zona glomerulosa cells. Results: BP and urine albumin in the LSD1+/- compared to the LSD1+/+ were not different at any age (Table). However, the LSD1+/- had greater ALDO/PRA ratios at 18 weeks compared with the LSD1+/+, but lower ALDO levels and ex vivo ALDO production at 52 and 75 weeks. Associated with this phenotype, the LSD1+/- showed significantly higher rate of all-cause mortality than the LSD1+/+. Conclusion: Lack of LSD1 caused dysregulation of ALDO production in both male and female mice. But the cardiovascular outcomes are different. The LSD1+/- females in contrast to males do not develop hypertension or albuminuria even at 75 weeks of age. However, the females do die at a faster rate than the males of a variety of causes. Thus, there is considerable sexual dimorphism in the pathogenesis of cardiovascular outcomes associated with dysregulation of adrenal ALDO production mediated by lack of LSD1.

2019 ◽  
Vol 240 (2) ◽  
pp. 111-122 ◽  
Author(s):  
Yuefei Huang ◽  
Pei Yee Ting ◽  
Tham M Yao ◽  
Tsuyoshi Homma ◽  
Danielle Brooks ◽  
...  

Human risk allele carriers of lysine-specific demethylase 1 (LSD1) and LSD1-deficient mice have salt-sensitive hypertension for unclear reasons. We hypothesized that LSD1 deficiency causes dysregulation of aldosterone’s response to salt intake resulting in increased cardiovascular risk factors (blood pressure and microalbumin). Furthermore, we determined the effect of biological sex on these potential abnormalities. To test our hypotheses, LSD1 male and female heterozygote-knockout (LSD1+/−) and WT mice were assigned to two age groups: 18 weeks and 36 weeks. Plasma aldosterone levels and aldosterone production from zona glomerulosa cells studied ex vivo were greater in both male and female LSD1+/− mice consuming a liberal salt diet as compared to WT mice consuming the same diet. However, salt-sensitive blood pressure elevation and increased microalbuminuria were only observed in male LSD1+/− mice. These data suggest that LSD1 interacts with aldosterone’s secretory response to salt intake. Lack of LSD1 causes inappropriate aldosterone production on a liberal salt diet; males appear to be more sensitive to this aldosterone increase as males, but not females, develop salt sensitivity of blood pressure and increased microalbuminuria. The mechanism responsible for the cardiovascular protective effect in females is uncertain but may be related to estrogen modulating the effect of mineralocorticoid receptor activation.


1971 ◽  
Vol 67 (1) ◽  
pp. 159-173
Author(s):  
A. Peytremann ◽  
R. Veyrat ◽  
A. F. Muller

ABSTRACT Variations in plasma renin activity and urinary aldosterone excretion were studied in normal subjects submitted to salt restriction and simultaneous inhibition of ACTH production with a new synthetic steroid, 6-dehydro-16-methylene hydrocortisone (STC 407). At a dose of 10 mg t. i. d. this preparation exerts an inhibitory effect on the pituitary comparable to that of 2 mg of dexamethasone. In subjects maintained on a restricted salt intake, STC 407 does not delay the establishment of an equilibrium in sodium balance. The increases in endogenous aldosterone production and in plasma renin activity are also similar to those seen in the control subjects. A possible mineralocorticoid effect of STC 407 can be excluded. Under identical experimental conditions, the administration of dexamethasone yielded results comparable to those obtained with STC 407.


1991 ◽  
Vol 37 (10) ◽  
pp. 1843-1848 ◽  
Author(s):  
E G Biglieri ◽  
C E Kater

Abstract Adrenocortical causes of hypertension are established by examining the mineralocorticoid hormones produced in the zona glomerulosa and zona fasciculata. In the zona glomerulosa, aldosterone excess leads to hypertension, hypokalemia, and suppressed plasma renin activity, with increased concentrations of urinary aldosterone (either as the 18-glucuronide or free aldosterone) as an index of its production. Identifying a tumor by computed tomography scan verifies the diagnosis of a correctable lesion. If no tumor is found, several maneuvers are used to identify primary adrenal hyperplasia, a disorder with autonomous aldosterone production, for which reduction of adrenal mass is curative. The zona fasciculata has two major pathways: the 17-deoxy pathway, where deoxycorticosterone (DOC) and corticosterone are the significant steroids, and the 17-hydroxy pathway, which leads to cortisol production. Tumors of the 17-deoxy pathway, DOC-producing adenomas, have increased concentrations of DOC and its precursor steroids, normal concentrations of cortisol, and suppression of aldosterone production secondary to suppression of the renin system. Two enzymatic defects in the zona fasciculata, 11 beta- and 17 alpha-hydroxylase deficiency, can be first readily identified by the virilization in the former, hypogonadal features in the latter. Steroid patterns are diagnostic. DOC is produced in excess in both deficiencies and is the cause of the hypertension. Deficient or impaired 11 beta-hydroxy steroid dehydrogenase in the apparent mineralocorticoid excess syndrome or after licorice ingestion retards the conversion of cortisol to inactive cortisone in the kidney, leading to mineralocorticoid hypertension; this leads to suppression of the renin system and subsequently of aldosterone.


2021 ◽  
Author(s):  
Shadi K Gholami ◽  
Chee Sin Tay ◽  
Jessica M Lee ◽  
Eleanor Zagoren ◽  
Stephen A Maris ◽  
...  

Inconsistencies have been reported on the effect of sex on aldosterone levels leading to clinical confusion. The reasons for these inconsistencies, are uncertain but include: estrogen and/or its receptor modulating target gene responses to mineralocorticoid receptor activation and aldosterone secretagogues’ levels. This study’s goal was to determine whether aldosterone’s biosynthesis also differed by sex. Two approaches were used. First, plasma renin activity (PRA) and aldosterone were measured in rats. Both were significantly higher in males. Secondly, using rat zona glomerulosa (ZG) cells, we assessed three ex-vivo areas:1) activity/levels of early steps in aldosterone’s biosynthesis (StAR and CYP11A1); 2) activity/levels of a late step (CYP11B2); and 3) the status of the MR mediated, ultrashort-feedback-loop. Females had higher expression of CYP11A1 and StAR; and increased CYP11A1 activity (increased pregnenolone/ corticosterone levels) but did not differ in CYP11B2 expression or activity (aldosterone/ levels). Activating the ZG’s MR (thereby activating the ultrashort-feedback-loop) reduced CYP11B2’s activity similarly in both sexes. Ex-vivo, these molecular effects were accompanied, in females, by lower aldosterone basally but higher aldosterone with angiotensin II stimulation. In conclusion, we documented that not only was there a sex-mediated difference in the activity of aldosterone’s biosynthesis, but also these differences at the molecular level, help explain the variable reports on aldosterone’s circulating levels. Basally, both in-vivo and ex-vivo, males had higher aldosterone levels, likely secondary to higher aldosterone secretagogue levels. However, in response to acute stimulation, aldosterone levels are higher in females because of the greater levels and/or activity of their StAR/CYP11A1.


1986 ◽  
Vol 111 (2) ◽  
pp. 222-227 ◽  
Author(s):  
K. Uchida ◽  
S. Azukizawa ◽  
N. Imaizumi ◽  
T. Kigoshi ◽  
I. Yamamoto ◽  
...  

Abstract. To assess the nature of the heparin-induced aldosterone deficiency, we investigated the stimulatory effect of angiotensin II (All) on aldosterone and its precursor steroids in adrenal zona glomerulosa cells from heparin-treated rats compared with those in the cells from vehicle-treated rats. Heparin-treated rats had low plasma aldosterone levels, high plasma renin activity and plasma All levels, and normal plasma corticosterone level 6 weeks after the treatment (1500 IU/kg, twice daily). Basal aldosterone production, when corrected to a uniform number of cells per group, was similar in the cells from heparin- and vehicle-treated rats. The cells from heparin-treated rats had a less sensitive and lower response of aldosterone production to All; an increase by 4 orders of magnitude in the threshold dose for All and a decrease in the maximum All-stimulated level. The maximum All-stimulated levels, but not the basal levels, of pregnenolone, corticosterone and 18-OHB production were low in the cells from heparin-treated rats. ACTH caused a similar stimulatory effect on aldosterone production in the cells from heparin- and vehicle-treated rats. The cells from heparin-treated rats had a less sensitive and lower response of aldosterone production to potassium; an increase by one order of magnitude in the threshold dose for potassium and a decrease in the maximum potassium-stimulated level, presumably because of the glomerulosa hyporesponsivness to AII. These results suggest that our heparin-treated rats have selective impairment of adrenal zona glomerulosa cells,


2008 ◽  
Vol 295 (6) ◽  
pp. F1635-F1640 ◽  
Author(s):  
Yuqiang Ge ◽  
Alan Bagnall ◽  
Peter K. Stricklett ◽  
David Webb ◽  
Yuri Kotelevtsev ◽  
...  

The collecting duct (CD) endothelin (ET) system regulates blood pressure (BP) and Na excretion. CD-specific knockout (KO) of ET-1 causes hypertension, CD-specific KO of the ETA receptor does not alter BP, while CD-specific KO of the ETB receptor increases BP to a lesser extent than CD ET-1 KO. These findings suggest a paracrine role for CD-derived ET-1; however, they do not exclude compensation for the loss of one ET receptor by the other. To examine this, mice with CD-specific KO of both ETA and ETB receptors were generated (CD ETA/B KO). CD ETA/B KO mice excreted less urinary Na than controls during acute or chronic Na loading. Urinary aldosterone excretion and plasma renin concentration were similar during Na intake and both fell comparably during Na loading. On a normal sodium diet, CD ETA/B KO mice had increased BP, which increased further with high salt intake. The degree of BP elevation during normal Na intake was similar to CD ET-1 KO mice and higher than CD ETB KO animals. During 1 wk of Na loading, CD ETA/B KO mice had higher BPs than CD ETB KO, while BP was less than CD ET-1 KOs until the latter days of Na loading. These studies suggest that 1) CD ETA/B deficiency causes salt-sensitive hypertension, 2) CD ETA/B KO-associated Na retention is associated with failure to suppress the renin-angiotensin-aldosterone system, and 3) CD ETA and ETB receptors exerts a combined hypotensive effect that exceeds that of either receptor alone.


1998 ◽  
Vol 274 (1) ◽  
pp. R255-R261 ◽  
Author(s):  
L. G. Melo ◽  
A. T. Veress ◽  
C. K. Chong ◽  
S. C. Pang ◽  
T. G. Flynn ◽  
...  

Atrial natriuretic peptide (ANP), a peptide hormone produced by the heart, exerts a chronic hypotensive effect. Knockout mice with a homozygous disruption of the pro-ANP gene (−/−) are incapable of producing ANP and are hypertensive relative to their wild-type (+/+) siblings. Previous studies showed that arterial blood pressure (ABP) was further increased in conscious −/− mice kept for 2 wk on 2% salt, but not in anesthetized −/− mice after 1 wk on 8% salt. To determine whether inconsistencies in observed effects of salt on ABP of −/− mice are due to duration of increased salt intake and/or the state of consciousness of the animals, we measured ABP from an exteriorized carotid catheter during and after recovery from anesthesia with ketamine-xylazine in adult +/+ and −/− mice kept on low (LS; 0.008% NaCl)- or high (HS; 8% NaCl)-salt diets for 3–4 wk. Conscious ABP ± SE (mmHg) of +/+ mice did not differ significantly on either diet (HS, 113 ± 3; LS, 110 ± 5). However, on HS diet −/− mice had significantly higher ABP (135 ± 3; P < 0.001) than both −/− (115 ± 2) and +/+ (110 ± 5) mice on LS diet. Anesthesia decreased ABP in all groups, but the genotype- and diet-related differences were preserved. Plasma renin activity (PRA, ng ANG I ⋅ ml−1 ⋅ h−1) in blood collected at termination of experiment was appropriately different on the 2 diets in +/+ mice (HS, 4.9 ± 1.9; LS, 21 ± 2.8). However, PRA failed to decrease in −/− mice on HS diet (HS, 18 ± 2.9; LS, 19 ± 3.7). Independent of genotype, concentration of endothelin-1 (ET-1, pg/mg protein) and endothelial constitutive NOS (ecNOS, density/100 μg protein) was significantly elevated in kidneys of mice fed on HS diet (ET-1 −/−, 31 ± 4.7 and +/+, 32 ± 4.1; ecNOS −/−, 160 ± 19 and +/+, 156 ± 19) compared with mice fed on LS diet (ET-1 −/−, 19 ± 1.9 and +/+, 21 ± 1.8; ecNOS −/−, 109 ± 13 and +/+, 112 ± 18). We conclude that, regardless of the state of alertness, −/− mice develop salt-sensitive hypertension after prolonged feeding on HS, in part due to their inability to reduce PRA, whereas the specific renal upregulation of ecNOS and ET-1 in response to HS intake may be an ANP-independent adaptive adjustment aimed at improving kidney function and counteracting the pressor effect of salt.


1993 ◽  
Vol 264 (2) ◽  
pp. H505-H511 ◽  
Author(s):  
M. Weinstock ◽  
M. Borosh

The aim of this study was to determine the effect of an increase in dietary salt on blood pressure (BP), Na+ balance, and plasma renin activity (PRA) in normotensive rabbits bred for differences in cardiac baroreflex sensitivity (BRS). Food and fluid intake, BP, heart rate, body weight, PRA, hematocrit, and creatinine clearance were monitored weekly and Na+ balance daily for 3 wk each on normal NaCl (8 meq/day) and high salt (32 meq/day) in 27 rabbits of the second and third generation of animals bred for high BRS (group I, 6.1 +/- 0.3 beats.min-1.mmHg-1, n = 9) or low BRS (group II, 3.61 +/- 0.1 beats.min-1.mmHg-1, n = 18). BRS was assessed in each animal on normal salt and at the end of the high-salt period. Both systolic and diastolic BP rose by > 10 mmHg in 50% of group II and by < 5 mmHg in the remainder and in all group I. The rise in BP was associated with Na+ and fluid retention and weight gain during the first 2 wk, which returned to presalt levels by the 3rd wk, although BP continued to rise. The lack of effect on BP in the remaining nine group II was associated with a marked sensitization of their BRS by the high salt to 6 +/- 0.4 beats.min-1.mmHg-1. BRS remained unchanged in the other rabbits. A highly significant correlation (P < 0.001) was found between the increment of BP and BRS after 3 wk of raised salt intake.(ABSTRACT TRUNCATED AT 250 WORDS)


2017 ◽  
Vol 232 (3) ◽  
pp. 525-534 ◽  
Author(s):  
Cherish Chong ◽  
Anis Hamid ◽  
Tham Yao ◽  
Amanda E Garza ◽  
Luminita H Pojoga ◽  
...  

We posit the existence of a paracrine/autocrine negative feedback loop, mediated by the mineralocorticoid receptor (MR), regulating aldosterone secretion. To assess this hypothesis, we asked whether altering MR activity in zona glomerulosa (ZG) cells affects aldosterone production. To this end, we studied ex vivo ZG cells isolated from male Wistar rats fed chow containing either high (1.6% Na+ (HS)) or low (0.03% Na+ (LS)) amount of sodium. Western blot analyses demonstrated that MR was present in both the ZG and zona fasciculata/zona reticularis (ZF/ZR/ZR). In ZG cells isolated from rats on LS chow, MR activation by fludrocortisone produced a 20% and 60% reduction in aldosterone secretion basally and in response to angiotensin II (ANGII) stimulation, respectively. Corticosterone secretion was increased in these cells suggesting that aldosterone synthase activity was being reduced by fludrocortisone. In contrast, canrenoic acid, an MR antagonist, enhanced aldosterone production by up to 30% both basally and in response to ANGII. Similar responses were observed in ZG cells from rats fed HS. Modulating glucocorticoid receptor (GR) activity did not alter aldosterone production by ZG cells; however, altering GR activity did modify corticosterone production from ZF/ZR/ZR cells both basally and in response to adrenocorticotropic hormone (ACTH). Additionally, activating the MR in ZF/ZR/ZR cells strikingly reduced corticosterone secretion. In summary, these data support the hypothesis that negative ultra-short feedback loops regulate adrenal steroidogenesis. In the ZG, aldosterone secretion is regulated by the MR, but not the GR, an effect that appears to be secondary to a change in aldosterone synthase activity.


2015 ◽  
Vol 308 (1) ◽  
pp. R73-R77 ◽  
Author(s):  
Hershel Raff ◽  
Ashley Gehrand ◽  
Eric D. Bruder ◽  
Matthew J. Hoffman ◽  
William C. Engeland ◽  
...  

The classic renin-angiotensin system is partly responsible for controlling aldosterone secretion from the adrenal cortex via the peptide angiotensin II (ANG II). In addition, there is a local adrenocortical renin-angiotensin system that may be involved in the control of aldosterone synthesis in the zona glomerulosa (ZG). To characterize the long-term control of adrenal steroidogenesis, we utilized adrenal glands from renin knockout (KO) rats and compared steroidogenesis in vitro and steroidogenic enzyme expression to wild-type (WT) controls (Dahl S rat). Adrenal capsules (ZG; aldosterone production) and subcapsules [zona reticularis/fasciculata (ZFR); corticosterone production] were separately dispersed and studied in vitro. Plasma renin activity and ANG II concentrations were extremely low in the KO rats. Basal and cAMP-stimulated aldosterone production was significantly reduced in renin KO ZG cells, whereas corticosterone production was not different between WT and KO ZFR cells. As expected, adrenal renin mRNA expression was lower in the renin KO compared with the WT rat. Real-time PCR and immunohistochemical analysis showed a significant decrease in P450aldo ( Cyp11b2) mRNA and protein expression in the ZG from the renin KO rat. The reduction in aldosterone synthesis in the ZG of the renin KO adrenal seems to be accounted for by a specific decrease in P450aldo and may be due to the absence of chronic stimulation of the ZG by circulating ANG II or to a reduction in locally released ANG II within the adrenal gland.


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