title: Angiotensin-converting enzyme (ACE) gene polymorphism and the erythrocyte sodium-lithium countertransporter (SLC) phenotype in hypertension.
abstract: It has been suggested that the association between altered behaviour of the erythrocyte sodium-lithium countertransporter (SLC) and hypertension could be secondary to its association with the risk of vascular disease rather than raised blood pressure (BP) per se. Homozygosity for the angiotensin-converting enzyme (ACE) deletion allele has also been linked to a more severe phenotype for cardiovascular disease. The present study investigated whether there is an association between these two indicators of vascular risk in patients with hypertension. The kinetic characteristics of the countertransporter (SLC activity, Vmax and KNa) of patients having the ID ACE-genotype (n = 16) were compared with those patients who had the DD genotype (n = 12). The median (range) SLC activity (mmol Li/l Red Blood Cells.h) in the ID (0.221 [0.061-0.422]) and DD (0.173 [0.094-0.408]) groups were similar (P = 0.28; Mann-Whitney). No significant differences in Vmax (mmol Li/l RBC.h) emerged between the two study groups (0.279 + 0.124 [ID] vs 0.244 + 0.123 [DD]; P = 0.46; unpaired Student's t-test); similarly, no differences emerged between the two groups with respect to KNa (median [range]; ID, 39.8 [12.4-84.4] vs DD, 35.9 [14.6-78.3]; P = 0.47). These data suggest that the SLC phenotype and the ACE-D allele dose are risk factors for cardiovascular disease that function independently of one another.
authors.affiliation: Department of Clinical Pharmacology and Therapeutics, Charing Cross and Westminster Medical School, Chelsea and Westminster Hospital, London, UK.
authors.forename: T C
authors.initials: TC
authors.lastname: Hardman
authors.forename: A S
authors.initials: AS
authors.lastname: Wierzbicki
authors.forename: P
authors.initials: P
authors.lastname: Croft
authors.forename: M
authors.initials: M
authors.lastname: Feher
authors.forename: A
authors.initials: A
authors.lastname: Cox
authors.forename: A F
authors.initials: AF
authors.lastname: Lant
mesh_terms: D000368:Aged; D017920:Antiporters / Q000032:analysis*; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D006973:Hypertension / Q000235:genetics / Q000378:metabolism*; D008094:Lithium / Q000378:metabolism*; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D012964:Sodium / Q000378:metabolism*
chemical_list: D017920:Antiporters; C045885:sodium-lithium countertransporter; D008094:Lithium; D012964:Sodium; D007703:Peptidyl-Dipeptidase A