Further ethnic differences in the renal sodium-dopamine relationship: its uncoupling in Iranian but not in Thai normotensive subjects.
Dopamine is a natriuretic hormone and is synthesized in the kidney in response to a sodium load. This relationship results in a positive correlation between urinary sodium and dopamine outputs. Uncoupling of the renal sodium-dopamine relationship is reflected in a loss of this correlation and will result in the sluggish excretion of a sodium load. We measured 24-h urinary sodium and dopamine outputs in Thais and Iranians, who traditionally have very different dietary salt environments (salt-rich and salt-scarce, respectively). There was a highly significant positive correlation between sodium and dopamine in the Thais (r = 0.53, P less than 0.001) but no suggestion of such a correlation in the Iranians (r = 0.03). We hypothesize that in some races the uncoupling of the renal sodium-dopamine relationship, possibly as a mechanism to help conserve dietary sodium, predisposes the race to the development of hypertension when the individuals encounter a salt-rich diet.
Critchley
J A
JA
Department of Clinical Pharmacology, University of Edinburgh, UK.
Makarananda
K
K
Balali-Mood
M
M
Sriwatanakul
K
K
Lee
M R
MR
D004298:Dopamine / Q000652:urine*; D005260:Female; D006801:Humans; D007492:Iran / Q000208:ethnology; D007668:Kidney / Q000502:physiology*; D008297:Male; D012964:Sodium / Q000652:urine*; D013785:Thailand / Q000208:ethnology
D012964:Sodium; D004298:Dopamine