Diabetes mellitus is known to be associated with sodium retention. The
aim of the present paper was to investigate the possible role of the
renal dopaminergic system in the disturbed sodium homeostasis of Type
2 diabetic patients. The urinary dopamine excretion, which represents
the local kidney production, was lower in Type 2 diabetic patients as
compared to controls and decreased in insulin treated patients as comp
ared to patients treated without insulin. Urinary dopamine excretion c
orrelated positively with sodium excretion in non-insulin treated pati
ents and in controls, but not in insulin treated patients. In contrast
to findings in healthy Volunteers, an intravenous sodium load failed
to increase the dopamine excretion in Type 2 diabetic patients, despit
e similar increments in sodium excretion. A low-dose dopamine infusion
caused significantly lower natriuretic responses in insulin treated T
ype 2 diabetic patients as compared to controls, but not in non-insuli
n treated patients. These findings suggest that Type 2 diabetic patien
ts display a derangement of the renal dopaminergic system, which is ac
centuated by insulin treatment. Copyright (C) 1996 Elsevier Science Ir
eland Ltd.