THE S-A GENE - PREDISPOSITION TO HYPERTENSION AND RENAL-FUNCTION IN MAN

1. The S-A gene is expressed in the kidneys and is associated with hyp ertension in man and experimental animal models, Predisposition to hyp ertension is associated with renal haemodynamic abnormalities and incr eased renal S-A gene expression. 2. We studied the distribution of the S-A gene alleles (A1, A2), defined by the PstI polymorphism, in young adults with contrasting predisposition to hypertension to determine w hether genetic variation at the S-A gene locus is associated with vari ations in renal haemodynamics, electrolyte metabolism and the renin-an giotensin system. 3. The frequency of the A2 allele was not significan tly different between subjects with high personal and parental blood p ressures and subjects with low personal and parental blood pressures, We detected no overall relationship between blood pressures and S-A ge notype, even after taking sodium intake into account. 4. Glomerular fi ltration rate, renal blood flow, renal vascular resistance, plasma vol ume, exchangeable sodium and total body water did not differ according to S-A genotypes, Moreover, we detected no significant effect of S-A genotype on circulating components of the renin-angiotensin system or atrial natriuretic peptide. 5. In our population, genetic variation at the S-A gene locus defined by PstI polymorphism does not influence th e renal characteristics that contribute to the development of hyperten sion.