Gordon's syndrome: increased maximal rate of the Na-K-Cl cotransport and erythrocyte membrane replacement of sphingomyelin by phosphatidylethanolamine.
OBJECTIVE
Gordon's syndrome comprises hypertension, hyperchloremic acidemia, hyperkalemia and intact renal function. We hypothesize that disturbances of one or more cell membrane ion carriers, handling sodium, chloride and potassium, might be relevant in this disorder and, furthermore, that such disturbances might be related to altered.cell membrane composition.


METHODS
In a patient diagnosed with Gordon's syndrome, we assessed the kinetics (K(m) and maximal rate) of four membrane sodium transport systems in sodium-enriched erythrocytes, according to the technique of Garay. We also measured the lipid composition of erythrocyte membrane in this patient and 69 essential hypertensive controls, using the latroscan technique.


RESULTS
Compared to reference values of patients with essential hypertension, this patient exhibited a marked increase in the maximal rate of the Na+-K+-2Cl(-)-cotransport (964.0 micromol/l per cell versus the 391.6 +/- 222 micromol/l per cell in essential hypertensives). Also, there was an increased concentration of erythrocyte membrane phosphatidylethanolamine and a reduced concentration of sphingomyelin (27.9 and 11.1% versus 17.9 +/- 3.8% and 18.2 +/- 3.4%, respectively).


CONCLUSIONS
We conclude that this abnormality in membrane Na+-K+-2Cl- cotransport could be responsible for the hyperkalemia, hyperchloremic acidemia and increased reabsorption of sodium observed in this condition and, furthermore, that such disturbance in membrane cotransport might be related to altered phospholipid concentration in cell membranes.
Stiefel
P
P
Departamento de Bioquímica Clínica del Hospital Universitario Virgen del Rocio, Spain. stiefel@cica.es
García-Morillo
S
S
Miranda
M L
ML
García-Donas
M A
MA
Pamies
E
E
Villar
J
J
Carneado
J
J
D000293:Adolescent; D002352:Carrier Proteins / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D006801:Humans; D006947:Hyperkalemia / Q000378:metabolism; D006973:Hypertension / Q000378:metabolism*; D008297:Male; D010714:Phosphatidylethanolamines / Q000378:metabolism*; D011546:Pseudohypoaldosteronism / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters; D013109:Sphingomyelins / Q000378:metabolism*
D002352:Carrier Proteins; D010714:Phosphatidylethanolamines; D028021:Sodium-Potassium-Chloride Symporters; D013109:Sphingomyelins