scholarly journals Salt-sensitive (Rapp) rats from Envigo spontaneously develop accelerated hypertension independent of ovariectomy on a low-sodium diet

2018 ◽  
Vol 315 (5) ◽  
pp. R915-R924 ◽  
Author(s):  
Amrita V. Pai ◽  
Crystal A. West ◽  
Aline M. A. de Souza ◽  
Xi Cheng ◽  
David A. West ◽  
...  
Keyword(s):  
Reference Genome ◽  
Strain Differences ◽  
Detectable Effect ◽  
Single Nucleotide ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Ovarian Status ◽  
Induced Hypertension ◽  
Accelerated Hypertension ◽  
The Mean

Inbred salt-sensitive (SS) rats developed by John Rapp and distributed by Harlan (SS/JrHsd) were shown to model ovariectomy-induced hypertension because on a low-sodium (LS) diet, ovariectomized SS (SS-OVX) animals became hypertensive in contrast to their sham-operated (SS-SHAM) normotensive littermates. After Harlan merged with Envigo in 2015, inconsistencies in the LS normotensive phenotype were reported. To further investigate these inconsistencies, we studied the effects of ovariectomy on SS and salt-resistant (SR) rats purchased from Envigo (SS/JrHsd/Env) between 2015 and 2017. The mean arterial pressure (MAP) in SS rats on a LS diet exceeded 160 mmHg at 7 mo old. Ovariectomy at 3 mo had no detectable effect on MAP from 4 to 7 mo, nor did ovariectomy at 1.5 mo significantly affect MAP at 10 mo in either strain; only strain differences in MAP were observed [MAP: SR-SHAM ( n = 7 rats), 102 ± 3 mmHg; SR-OVX ( n = 6 rats), 114 ± 1 mmHg; SS-SHAM ( n = 7 rats), 177 ± 6 mmHg; SS-OVX ( n = 5 rats), 190 ± 12 mmHg; where P < 0.0001 vs. SR, same ovarian-status for SS-SHAM and SS-OVX, respectively]. Whole genome sequencing revealed more genomic variants of SS/JrHsd/Env, including single nucleotide and insertion deletion polymorphisms and higher heterozygous/homozygous ratios compared with the reference genome, than for SS/JrHsd/Mcwi and SS/Jr rats maintained in Milwaukee, WI and Toledo, OH, respectively, and which still exhibit normal blood pressure on a LS diet. These findings demonstrate that the female SS/JrHsd/Env rat has genetically diverged from the original phenotype, which was normotensive on a LS diet when the ovaries were intact but rapidly developed hypertension when the ovaries were removed. Nonetheless, the SS/JrHsd/Env rat could be a valuable model that complements other animal models of spontaneous hypertension used to investigate mechanisms of essential hypertension.

Urinary Dopamine in Man and Rat: Effects of Inorganic Salts on Dopamine Excretion

1978 ◽  
Vol 55 (2) ◽  
pp. 167-173 ◽  
Author(s):  
S. G. Ball ◽  
N. S. Oats ◽  
M. R. Lee
Keyword(s):  
Volume Expansion ◽  
Male Volunteer ◽  
Sodium Ion ◽  
Normal Male ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Simple Effect ◽  
Urinary Dopamine ◽  
The Mean ◽  
Excretion Rates

1. Plasma and urine free dopamine (3,4-dihydroxyphenethylamine) were measured in six normal male volunteer subjects and the urinary clearance of dopamine was calculated for each subject. 2. The excretion rates for free dopamine in man were greater than could be explained by simple renal clearance. It was concluded that free dopamine must, therefore, be formed in the kidney. 3. Changes in urinary dopamine excretion were studied in four groups of rats initially maintained on a low sodium diet and then given equimolar dietary supplements of NaCl, NaHCO3, KCl or NH4Cl, to study the specificity of the previously observed increase in dopamine excretion after increased dietary NaCl. 4. The mean dopamine excretion increased significantly in rats given NaCl, KCl and NH4Cl, whereas dopamine excretion decreased in those given NaHCO3. 5. The failure of dopamine excretion to rise in response to loading with NaHCO3 was unexpected, and argues against a simple effect of volume expansion by the sodium ion. The increase in dopamine excretion with KCl and NH4Cl showed that this response was not specific to the sodium ion.

PLASMA ALDOSTERONE CONCENTRATIONS RELATED TO 17α-HYDROXYPROGESTERONE IN CONGENITAL ADRENAL HYPERPLASIA

1976 ◽  
Vol 82 (3) ◽  
pp. 572-586 ◽  
Author(s):  
M. T. Pham-Huu-Trung ◽  
M. C. Raux ◽  
M. Gourmelen ◽  
M. C. Baron ◽  
F. Girard ◽  
...  
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
Plasma Aldosterone ◽  
Adrenal Hyperplasia ◽  
Acth Stimulation ◽  
Hydroxylase Deficiency ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
The Mean ◽  
21 Hydroxylase Deficiency

ABSTRACT Plasma aldosterone and 17α-hydroxyprogesterone (17-OHP) concentrations were measured in 35 patients with congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency. Ten patients had never been treated and among them were 4 salt-losing infants. Both aldosterone and 17-OHP were high in the 6 untreated non salt-losers. The values ranged respectively from 110 to 376 pg/ml and from 150 to 292 ng/ml. Results were variable in the 4 salt-losers. Three out of 5 untreated non salt-losers who were submitted to a low sodium diet, responded by doubling their aldosterone levels. When plasma 17-OHP concentrations were < 30 ng/ml, the mean aldosterone level in the treated non salt-losers (n = 6) was 15.3 pg/ml ± 4.3 (se). This value was not different from the mean level found in the control children (n = 7), 18.8 pg/ml ± 3.2. In the treated salt-losers (n = 9), the measured aldosterone levels were ≦ 10 pg/ml 7 times out of 9. When the treated patients exhibited plasma 17-OHP concentrations > 30 ng/ml, the salt-losers (n = 11) were distinguished from the non salt-losers (n = 8) in that they showed a significantly lower aldosterone mean level, 24.6 pg/ml ± 4.3 against 69 pg/ml ± 13.4 found in the non salt-losers. The salt-losers displayed no aldosterone increases to synthetic ACTH stimulation under treatment or at the withdrawal of treatment, while positive aldosterone responses were often observed in the non salt-losers. In the latter group, studied under different conditions (with and without therapy, on low sodium diet, after ACTH test) a significant correlation was found between aldosterone and 17-OHP levels expressed in log. values, (n = 38, r = 0.80, P < 0.001). The relationship could also be established with the values obtained from all the salt-losers, but it was less significant, (n = 35, r = 0.46, P < 0.02).

Assessing single nucleotide polymorphism selection methods for the development of a low-density panel optimized for imputation in South African Drakensberger beef cattle

2021 ◽  
Author(s):  
Simon F Lashmar ◽  
Donagh P Berry ◽  
Rian Pierneef ◽  
Farai C Muchadeyi ◽  
Carina Visser
Keyword(s):  
South African ◽  
Clustering Algorithm ◽  
Imputation Accuracy ◽  
Developed Countries ◽  
Genotype Imputation ◽  
Selection Strategy ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Single Nucleotide Polymorphism Selection ◽  
The Mean

Abstract A major obstacle in applying genomic selection (GS) to uniquely adapted local breeds in less-developed countries has been the cost of genotyping at high densities of single nucleotide polymorphisms (SNP). Cost reduction can be achieved by imputing genotypes from lower to higher densities. Locally adapted breeds tend to be admixed and exhibit a high degree of genomic heterogeneity thus necessitating the optimization of SNP selection for downstream imputation. The aim of this study was to quantify the achievable imputation accuracy for a sample of 1,135 South African (SA) Drakensberger using several custom-derived lower-density panels varying in both SNP density and how the SNP were selected. From a pool of 120,608 genotyped SNP, subsets of SNP were chosen 1) at random, 2) with even genomic dispersion, 3) by maximizing the mean minor allele frequency (MAF), 4) using a combined score of MAF and linkage disequilibrium (LD), 5) using a partitioning-around-medoids (PAM) algorithm, and finally 6) using a hierarchical LD-based clustering algorithm. Imputation accuracy to higher density improved as SNP density increased; animal-wise imputation accuracy defined as the within-animal correlation between the imputed and actual alleles ranged from 0.625 to 0.990 when 2,500 randomly selected SNP were chosen versus a range of 0.918 to 0.999 when 50,000 randomly selected SNP were used. At a panel density of 10,000 SNP, the mean (standard deviation) animal-wise allele concordance rate was 0.976 (0.018) versus 0.982 (0.014) when the worst (i.e., random) as opposed to the best (i.e., combination of MAF and LD) SNP selection strategy was employed. A difference of 0.071 units was observed between the mean correlation-based accuracy of imputed SNP categorized as low (0.01&lt;MAF≤0.1) versus high MAF (0.4&lt;MAF≤0.5). Greater mean imputation accuracy was achieved for SNP located on autosomal extremes when these regions were populated with more SNP. The presented results suggested that genotype imputation can be a practical cost-saving strategy for indigenous breeds such as the South African Drakensberger. Based on the results, a genotyping panel consisting of approximately 10,000 SNP selected based on a combination of MAF and LD would suffice in achieving a less than 3% imputation error rate for a breed characterized by genomic admixture on the condition that these SNP are selected based on breed-specific selection criteria.

Time for a Renewed Focus on the DASH-Low Sodium Diet

2021 ◽  
Vol 77 (21) ◽  
pp. 2635-2637
Author(s):  
Neha J. Pagidipati ◽  
Laura P. Svetkey
Keyword(s):  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium
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