Progesterone is needed to permit adaptation of the kidney to limit potassium loss in the urines. The investigators wonder whether progesterone or other adrenal hormon play the same role. The investigators will investigate surrenal hormone production in healthy subjects under a 7-day potassium depleted diet and in patients chronically hypokalaemic due to a renal loss of potassium.
The investigators will study the adaptation of steroidogenesis to potassium depletion in healthy volunteer, and the role of progesterone in renal adaptation to potassium depletion. Practically, healthy volunteers will be submitted twice to two periods of normal Na+/ high K+ diet (control period) followed by a normal Na+/ low K+ diet sustained by a pharmacological treatment with Kayexalate (K+-depleted condition). The subjects will be treated with either RU486 or a placebo, according to a randomization. The adrenal response will be evaluated after stimulation by Synacthen at baseline and at the end of each experimental period. A Synacthen test will be also done in 10 patients suffering of chronic hypokalemia linked to a hereditary tubulopathy inducing renal K+ leak called Gitelman syndrome and their plasma steroid profile will be established.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
26
Healthy subjects will be submitted twice at 15-30 day interval, to a low potassium diet (20mmol/day)
European George Pompidou Hospital
Paris, France
Effect of potassium depletion on plasma progesterone (Change from Baseline of progesterone)
Healthy subjects : Change from Baseline of progesterone in response to synacthen at day 8 in subject treated by placebo. Patients with Gitelman syndrome: Change from Baseline of progesterone in response to synacthen
Time frame: Day 1 and Day 8 of placebo period of treatment (healthy subjects) or once (Gitelman patients)
effect of RU 486 on renal adaptation to potassium depletion (Plasma potassium and kaliuresis will be monitored )
Plasma potassium and kaliuresis will be monitored during the 7-days potassium depletion in subjects treated by RU486 or placebo, according randomization
Time frame: Day 1 and day 8 of each period of treatment
Effect of potassium depletion on pulse pressure velocity (Pulse wave velocity and central blood pressure)
Pulse wave velocity and central blood pressure are measured before and after 7 days of potassium deprivated diet.
Time frame: At Day 1 and Day 8 of each period of treatment
Effect of potassium depletion on plasma progesterone under RU486 (Change from Baseline of progesterone)
Healthy subjects : Change from Baseline of progesterone in response to synacthen at day 8 in subject treated by RU486.
Time frame: Day 1 and Day 8 of placebo period of treatment (healthy subjects) or once (Gitelman patients)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.