Erythrocyte membrane calcium transport in patients with primary hyperparathyroidism.
The chronic effect of PTH on erythrocyte membrane Ca transport was examined. (Ca+Mg)ATPase activity and passive Sr influx were measured to assess the rate of passive Ca influx (total and inhibited by dihydropyridines [DHPs]), in erythrocytes from patients with primary hyperparathyroidism and normal controls. Erythrocyte Sr influx was lower in patients, due to a decreased DHP-sensitive Sr influx. Conversely, efflux activity of (Ca+Mg)ATPase was not different in patients and controls. We hypothesize that in primary hyperparathyroidism chronic PTH stimulation may induce a downregulation of the erythrocyte Ca influx mediated by DHP-sensitive Ca carrier.
Vezzoli
G
G
Department of Nephrology Dialysis and Hypertension, University of Milan, Italy.
Reina
M C
MC
Cusi
D
D
Casirati
P
P
Soldati
L
L
Azzani
T
T
Muirhead
R
R
Bianchi
G
G
D001692:Biological Transport; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002118:Calcium / Q000097:blood*; D004095:Dihydropyridines / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000201:enzymology / Q000378:metabolism*; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood* / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D009568:Nitrendipine / Q000494:pharmacology; D013324:Strontium / Q000378:metabolism
D004095:Dihydropyridines; C038806:1,4-dihydropyridine; D009568:Nitrendipine; D017301:Ca(2+) Mg(2+)-ATPase; D002118:Calcium; D013324:Strontium