Intra-erythrocytic sodium content in normotensive offspring of normotensive and hypertensive subjects: an epidemiological study.
An increase in intra-erythrocytic sodium (IENa) content has been proposed as a genetic marker of essential hypertension. Intra-erythrocytic sodium was studied using hypotonic lysis and flame photometry after four washings with isotonic MgCl2 in 240 normotensive subjects (aged 10-45 years) on a free diet with (F+, 121 patients) or without (F-, 119 patients) hypertensive parents, recruited from a random sample of the general population. Systolic blood pressure was significantly higher in males F+ than in males F- (130 +/- 2 versus 125 +/- 2 mmHg, mean +/- s.e.m., P < 0.05), while IENa did not differ. In contrast, intra-erythrocytic potassium content (IEK) was significantly lower and red cell sodium potassium (Na:K) ratio significantly higher in F+ than F-. This might reflect decreased NaK pump activity, or increased membrane permeability to cations which causes increased K leakage. No differences in blood pressure, IENa or IEK showed in female F+ versus F-. It is concluded that IENa is not a genetic marker of hypertension, and that it is probably influenced by exogenous factors. Being associated with differences in blood pressure, the abnormalities of IEK and Na:K ratio might be pathogenetically linked to an early increase in blood pressure.
Semplicini
A
A
Clinica Medica I, University of Padua, Italy.
Ambrosio
G B
GB
Rigon
E
E
Dissegna
L
L
Zamboni
S
S
Rossi
G
G
Pessina
A C
AC
Dal Palù
C
C
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D002648:Child; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005819:Genetic Markers; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000453:epidemiology / Q000235:genetics; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood*
D005819:Genetic Markers; D012964:Sodium; D011188:Potassium