Post by djoser-xyyman on Dec 7, 2011 16:06:03 GMT -5
Why do Blacks/Africans and other tropical people have higher Blood Pressure?
Theme – we have to exercise more ie sweat more. I always knew that. Now here is the proof.
========
CYP3A Variation and the Evolution of Salt-Sensitivity Variants
E. E. Thompson,1,2 H. Kuttab-Boulos,2 D. Witonsky,2 L. Yang,3 B. A. Roe,3 and A. Di Rienzo1,2
1Committee on Genetics and 2Department of Human Genetics, University of Chicago, Chicago; and 3Advanced Center for Genome
Technology, Department of Chemistry and Biochemistry, University of Oklahoma, Norman
The CYP3A5*1/*3 polymorphism, which is likely to influence salt and water retention and risk for salt-sensitive hypertension, was genotyped in 11,000 individuals from 52 worldwide population samples. The results reveal an unusual geographic pattern whereby the CYP3A5*3 frequency shows extreme variation across human populations and is significantly correlated with distance from the equator. Furthermore, we show that an unlinked variant, AGT M235T, previously implicated in hypertension and pre-eclampsia, exhibits a similar geographic distribution and is significantly correlated in frequency with CYP3A5*1/*3.
This allele, known as “CYP3A5*3,” was reported to have a frequency of ∼27%–50% among African Americans, 85%–95% among whites (Hustert et al. 2001; Kuehl et al. 2001), and 60%–73% among Asians (Hustert et al. 2001).
In addition, it has been suggested that the expressor allele may be associated with increased systolic blood pressure and mean arterial pressure in African Americans (Givens et al. 2003). The proposed mechanism involves the conversion of cortisol to 6b-hydroxycortisol by CYP3A5 in the kidney, which leads to higher reabsorption of sodium and water retention as well as the clinical phenotype of salt-sensitive hypertension
These findings argue for a shared selective pressure on saltsensitivity variants, with the intensity of selection varying in correlation with latitude
Theme – we have to exercise more ie sweat more. I always knew that. Now here is the proof.
========
CYP3A Variation and the Evolution of Salt-Sensitivity Variants
E. E. Thompson,1,2 H. Kuttab-Boulos,2 D. Witonsky,2 L. Yang,3 B. A. Roe,3 and A. Di Rienzo1,2
1Committee on Genetics and 2Department of Human Genetics, University of Chicago, Chicago; and 3Advanced Center for Genome
Technology, Department of Chemistry and Biochemistry, University of Oklahoma, Norman
The CYP3A5*1/*3 polymorphism, which is likely to influence salt and water retention and risk for salt-sensitive hypertension, was genotyped in 11,000 individuals from 52 worldwide population samples. The results reveal an unusual geographic pattern whereby the CYP3A5*3 frequency shows extreme variation across human populations and is significantly correlated with distance from the equator. Furthermore, we show that an unlinked variant, AGT M235T, previously implicated in hypertension and pre-eclampsia, exhibits a similar geographic distribution and is significantly correlated in frequency with CYP3A5*1/*3.
This allele, known as “CYP3A5*3,” was reported to have a frequency of ∼27%–50% among African Americans, 85%–95% among whites (Hustert et al. 2001; Kuehl et al. 2001), and 60%–73% among Asians (Hustert et al. 2001).
In addition, it has been suggested that the expressor allele may be associated with increased systolic blood pressure and mean arterial pressure in African Americans (Givens et al. 2003). The proposed mechanism involves the conversion of cortisol to 6b-hydroxycortisol by CYP3A5 in the kidney, which leads to higher reabsorption of sodium and water retention as well as the clinical phenotype of salt-sensitive hypertension
These findings argue for a shared selective pressure on saltsensitivity variants, with the intensity of selection varying in correlation with latitude
