1. The effect of dietary sodium on the urine dopamine excretion of eight hypertensive patients and six matched controls was studied under metabolic balance conditions over a 2 week period during which dietary sodium intake was increased from 20 to 220 mmol/day. 2. The control group showed the expected increase in dopamine excretion in response to sodium but the hypertensive patients showed an initial fall followed by a return to baseline values. 3. Neither group showed a rise in blood pressure but the hypertensive patients showed a greater weight gain on salt loading, although this change was not significant. The cumulative sodium balance was greater and more prolonged in the hypertensive patients, although this difference also did not attain statistical significance. 4. This defect in dopamine mobilization may be important in relation to renal sodium handling by patients with essential hypertension.
1. γ-Glutamyl l -dopa, a renal pro-drug for dopamine, was administered to rats before and after injection of glycerol, and to a control group which received water in place of glycerol. A third group of rats was given glycerol but no γ-glutamyl l -dopa. 2. The plasma creatinine in rats given γ-glutamyl l -dopa and glycerol was significantly lower than in rats receiving glycerol alone. 3. The fall in urine creatinine excretion, and polyuria, after glycerol was reduced by γ-glutamyl l -dopa and the natriuresis abolished. 4. γ-Glutamyl l -dopa given alone caused a 4000-fold increase in urine dopamine excretion, associated with a natriuresis. 5. The administration of γ-glutamyl l -dopa reduces the severity of renal failure produced by glycerol.
1. Urine free dopamine was estimated at predetermined points of the menstrual cycle in normal volunteer subjects and in women taking a combined oral contraceptive. 2. There was no alteration in 24 h urine dopamine during the normal menstrual cycle but, in contrast, combined oral contraceptives produced a fall which recovered premenstrually. 3. In 19 primigravid subjects 24 h urine free dopamine was estimated at monthly intervals throughout pregnancy and at the time of the postnatal examination. 4. Urine dopamine was elevated throughout pregnancy when compared with postnatal values. Women receiving an oral progestogen contraceptive at the time of the postnatal examination showed a further fall in urine dopamine.