scholarly journals Differences in the genotype frequencies of genes related to blood pressure regulation-a comparative study between South-West Europe and Peri-equatorial Africa

2021 ◽  
Vol 21 (4) ◽  
pp. 1669-76
Author(s):  
Laura Aguiar ◽  
Ildegário Semente ◽  
Joana Ferreira ◽  
Andreia Carvalho ◽  
Alda P Silva ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Genetic Variants ◽  
Compensatory Mechanisms ◽  
Selective Pressures ◽  
South West ◽  
Equatorial Africa ◽  
Sao Tome And Principe ◽  
Genotype Frequencies ◽  
Sodium Loss ◽  
Intron 4

Background: Since the emergence of the genus Homo, hominids have occupied a wide variety of environments, facing different selective pressures. Objectives: The aim this study is to compare genotype frequencies between South-West Europe and Peri-equatorial Africa in genes potentially modulators of blood pressure. Methods: The analyzed sample consisted of 325 individuals from Portugal and 226 individuals from Africa (48 from Mozambique and 178 from São Tomé and Príncipe). The following genetic variants were analyzed: intron 4 VNTR in eNOS, rs1050829 in G6PD, -3.7kb α-thalassemic deletion in HBA, rs1800457 in CYB5R3, Hp 1/2 genotype/phenotype in Hp and intron 16 I/D in ACE. Results: Frequencies of genotypes with the 4a allele in eNOS (p<0.001), the G allele in G6PD (p<0.001), the α-3.7 kb in HBA (p <0.001), the C allele in the CYB5R3 (p<0.001) were higher in Peri-equatorial Africa. The Hp 1.1 genotype of Hp has a higher frequency in Peri-equatorial Africa (p=0.002). ACE shows no significant differences. Conclusion: Results show differences in five genetic variants. Conditions of extreme heat and humidity, characteristic of Peri-equatorial Africa, have been associated with increased sodium loss. This study suggests that selected compensatory mechanisms printed in the genome, are nowadays risk factors for hypertension in Peri-equatorial Africa. Keywords: Blood pressure; genetics; Africa.

Abstract 119: Influence of Anesthetics on the Hemodynamic Response in a Rat Model of Hemorrhagic Shock

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Claudius Balzer ◽  
Franz J Baudenbacher ◽  
Susan S Eagle ◽  
Michele M Salzman ◽  
William J Cleveland ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Hemorrhagic Shock ◽  
Rat Model ◽  
Cardiovascular Response ◽  
Femoral Vein ◽  
Blood Pressure Measurement ◽  
Experimental Models ◽  
Sprague Dawley ◽  
Compensatory Mechanisms ◽  
Arterial Blood

Introduction: Experimental models of hemorrhagic shock (HS) in rats are important to test new treatments that may improve outcomes in humans, and general anesthesia is required during these experiments. The volatile anesthetic Isoflurane is known for its beneficial effects in rat HS models. Focusing on cardiovascular compensatory mechanisms, we wanted to evaluate Isoflurane versus the injectable anesthetic Pentobarbital in our rat model of mild HS (class 2). We hypothesize that Isoflurane during development of HS improves hemodynamics compared to Pentobarbital. Methods: Twelve Sprague-Dawley rats were initially anesthetized with an intraperitoneal (IP) injection of Pentobarbital (45 mg/kg) and intubated (1 L/min, FiO 2 0.25); heart rate (HR) was monitored by subcutaneous ECG needles. Femoral artery and vein were cannulated for continuous blood pressure measurement and delivery of fluids, respectively. In one group (n=7), anesthesia was continued with repeated IP injections of Pentobarbital (dose mg/kg), the other group (n=5) received continuous Isoflurane (1%). After 30 min of stabilization and administration of Heparin (100 IU/kg), HS was induced by removal of 1 ml of blood over 1 min via the femoral vein, repeated every 3 min until a volume of 5 ml of blood was removed. Mean arterial blood pressure (MAP) and HR were recorded and analyzed in LabChart. Results: During baseline, rats showed no significant differences in HR and MAP between both groups. After 5 ml of hemorrhage, both groups showed significant changes compared to baseline, with significantly higher MAP and HR in rats given only Pentobarbital. Conclusions: In our rat model of HS, Isoflurane dampens the physiologic response to compensate for mild hemorrhage. The cardiovascular response of rats in the Isoflurane group was a decrease of HR and MAP to every ml of hemorrhage, while rats given only Pentobarbital were able to maintain their MAP by raising their HR until decompensation.

Abstract 161: Identification of Genetic Variants Associated with Kidney Injury That Leads to Increased Blood Pressure

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Ashlyn C Harmon ◽  
Ashley C Johnson ◽  
Santosh Atanur ◽  
Klio Maratou ◽  
Tim Aitman ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Bone Marrow ◽  
Immune Response ◽  
Renal Function ◽  
Kidney Disease ◽  
Kidney Function ◽  
Genetic Variants ◽  
Kidney Injury ◽  
Chromosome 11 ◽  
Genomic Locus

Hypertension, diabetes and obesity, along with genetic predisposition, contribute to the growing number of chronic kidney disease patients. Our novel congenic model [S.SHR(11)] was developed through genetic modification of the Dahl salt-sensitive (S) rat, a model of hypertension related renal disease. The S.SHR(11) strain exhibits accelerated kidney injury compared to the already highly susceptible S rat. On either a low or high-salt diet, the S.SHR(11) model predominately exhibited more tubulointerstitial fibrosis compared to the S rat (17.1±1.29% vs. 12.9±1.22%). Increased α-SMA and macrophage infiltration was also observed. The S and S.SHR(11) had similar blood pressure (week 12), despite an early reduction in renal function in the S.SHR(11); however at an advanced age the S.SHR(11) demonstrated significantly higher blood pressure than the S (215±6.6 mm Hg vs. 183±5.9, respectively). This suggests that increased kidney injury is driving the development of hypertension later in life. Since these two animal models are identical with exception of chromosome 11, the causative genetic variants contributing to decreased renal function must reside within this region. The Dahl S and SHR genomes have been sequenced; this data provides a catalog of all the genetic variants between the two models. The 95% confidence interval of the genomic locus contains 28 non-synonymous SNP, with 15 of these SNP occurring within only three genes: Retnlg , Trat1 and Myh15. Two of these genes, Retnlg and Trat1, are known to play a role in immune response leading to our hypothesis that genetic variants in these genes alter protein function and lead to an increased immune response. Bone marrow transplant studies have been initiated to test our hypothesis and preliminary data shows that S rats who receive S.SHR(11) bone marrow have kidney function measurements similar to the S.SHR(11). The sequencing information has also lead to the development of nine new, more refined congenic strains. Through functional analysis of these new congenic animals, identification of the causative genetic variations will be expedited. In summary, we are employing a model of accelerated kidney disease to identify genes or genetic variants responsible for reduced kidney function and hypertension.

Cardiovascular and renal control in NOS-deficient mouse models

2003 ◽  
Vol 284 (3) ◽  
pp. R628-R638 ◽  
Author(s):  
Pablo A. Ortiz ◽  
Jeffrey L. Garvin
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Cardiac Function ◽  
Knockout Mice ◽  
Vascular Tone ◽  
Single Gene ◽  
No Production ◽  
Compensatory Mechanisms ◽  
Nos Isoforms ◽  
Regulation Of Vascular Tone

Nitric oxide (NO) plays an essential role in the maintenance of cardiovascular and renal homeostasis. Endogenous NO is produced by three different NO synthase (NOS) isoforms: endothelial NOS (eNOS), inducible NOS (iNOS), and neuronal NOS (nNOS). To investigate which NOS is responsible for NO production in different tissues, NOS knockout (−/−) mice have been generated for the three isoforms. This review focuses on the regulation of cardiovascular and renal function in relation to blood pressure homeostasis in the different NOS−/− mice. Although regulation of vascular tone and cardiac function in eNOS−/− has been extensively studied, far less is known about renal function in these mice. eNOS−/− mice are hypertensive, but the mechanism responsible for their high blood pressure is still not clear. Less is known about cardiovascular and renal control in nNOS−/− mice, probably because their blood pressure is normal. Recent data suggest that nNOS plays important roles in cardiac function, renal homeostasis, and regulation of vascular tone under certain conditions, but these are only now beginning to be studied. Inasmuch as iNOS is absent from the cardiovascular system under physiological conditions, it may become important to blood pressure regulation only during pathological conditions related to inflammatory processes. However, iNOS is constitutively expressed in the kidney, where its function is largely unknown. Overall, the study of NOS knockout mice has been very useful and produced many answers, but it has also raised new questions. The appearance of compensatory mechanisms suggests the importance of the different isoforms to specific processes, but it also complicates interpretation of the data. In addition, deletion of a single gene may have physiologically significant effects in addition to those being studied. Thus the presence or absence of a specific phenotype may not reflect the most important physiological function of the absent gene.

Complex cardiovascular diseases: the genetics of arterial hypertension

ESC CardioMed ◽  
2018 ◽  
pp. 732-736
Author(s):  
Georg Ehret
Keyword(s):  
Blood Pressure ◽  
Arterial Hypertension ◽  
Genetic Variants ◽  
Single Gene ◽  
Primary Hypertension ◽  
Genetic Types ◽  
Risk Variants ◽  
Cardiovascular Risk Prediction ◽  
Single Gene Defect ◽  
Substantial Extent

Arterial hypertension appears as two genetic types: primary hypertension is to a substantial extent determined by a large number of genetic risk variants, whereas rare patients with a familial hypertensive syndrome have a single gene defect that drives the elevated blood pressure. The familial hypertensive syndromes have been instrumental in highlighting blood pressure-regulating pathways that almost exclusively cluster in the kidney and in the mineralocorticoid pathways. Conversely, hundreds or more genetic variants cause the genetic component of primary hypertension and each risk variant causes a small blood pressure increase. The blood vessels appear to be one tissue in which these variants principally act and surprisingly there is little overlap with pathways of kidney and hormone pathways. Genetic testing is useful for the rare familial hypertensive syndrome, but in primary hypertension cardiovascular risk prediction can currently not be improved by genotyping.

scholarly journals Association of Established Blood Pressure Loci With 10‐Year Change in Blood Pressure and Their Ability to Predict Incident Hypertension

2020 ◽  
Vol 9 (16) ◽  
Author(s):  
Alaitz Poveda ◽  
Naeimeh Atabaki‐Pasdar ◽  
Shafqat Ahmad ◽  
Göran Hallmans ◽  
Frida Renström ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Genetic Variants ◽  
Association Studies ◽  
Risk Scores ◽  
Genome Wide Association Studies ◽  
Swedish Population ◽  
Long Term Changes ◽  
Traditional Risk Factors

Background Genome‐wide association studies have identified >1000 genetic variants cross‐sectionally associated with blood pressure variation and prevalent hypertension. These discoveries might aid the early identification of subpopulations at risk of developing hypertension or provide targets for drug development, amongst other applications. The aim of the present study was to analyze the association of blood pressure‐associated variants with long‐term changes (10 years) in blood pressure and also to assess their ability to predict hypertension incidence compared with traditional risk variables in a Swedish population. Methods and Results We constructed 6 genetic risk scores (GRSs) by summing the dosage of the effect allele at each locus of genetic variants previously associated with blood pressure traits (systolic blood pressure GRS (GRS SBP ): 554 variants; diastolic blood pressure GRS (GRS DBP ): 481 variants; mean arterial pressure GRS (GRS MAP ): 20 variants; pulse pressure GRS (GRS PP ): 478 variants; hypertension GRS (GRS HTN ): 22 variants; combined GRS (GRS com b ): 1152 variants). Each GRS was longitudinally associated with its corresponding blood pressure trait, with estimated effects per GRS SD unit of 0.50 to 1.21 mm Hg for quantitative traits and odds ratios (ORs) of 1.10 to 1.35 for hypertension incidence traits. The GRS comb was also significantly associated with hypertension incidence defined according to European guidelines (OR, 1.22 per SD; 95% CI, 1.10‒1.35) but not US guidelines (OR, 1.11 per SD; 95% CI, 0.99‒1.25) while controlling for traditional risk factors. The addition of GRS comb to a model containing traditional risk factors only marginally improved discrimination (Δarea under the ROC curve = 0.001–0.002). Conclusions GRSs based on discovered blood pressure‐associated variants are associated with long‐term changes in blood pressure traits and hypertension incidence, but the inclusion of genetic factors in a model composed of conventional hypertension risk factors did not yield a material increase in predictive ability.

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