Presence of a functional TSH receptor on human erythrocytes.
The presence of thyrotropin receptors (TSHR) has been reported in some extrathyroidal tissues but its physio-pathological role still remains unclear. TSH (seems to) affects the human erythrocytes Na(+)/K(+)-ATPase in vitro, however receptors on erythrocytes have not yet been described. In this work the effect of recombinant human TSH (rhTSH) on sites number and activity of erythrocyte Na(+)/K(+)-ATPase was investigated in a group of thyroidectomized patient enrolled for rhTSH test. As detected by (3)H-ouabain binding, rhTSH administration induced a significant increase in the number of sites (p=0.005) and in the Kd (p=0.006) of Na(+)/K(+)-ATPase. rhTSH did not induce significant difference in Na(+)/K(+)-ATPase activity measured by (86)Rb uptake. (125)I-TSH binding studies and Western blotting data showed the existence of TSHR in the erythrocytes of healthy donors. In conclusion The TSH action on Na(+)/K(+)-ATPase of human erythrocytes can be explained by the presence of TSHR.
Balzan
Silvana
S
Institute of Clinical Physiology, CNR, Via Moruzzi 1, Pisa 56124, Italy.
Nicolini
Giuseppina
G
Forini
Francesca
F
Boni
Giuseppe
G
Del Carratore
Renata
R
Nicolini
Andrea
A
Carpi
Angelo
A
Iervasi
Giorgio
G
D001665:Binding Sites; D015153:Blotting, Western; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011869:Radioligand Assay; D011989:Receptors, Thyrotropin / Q000097:blood*; D011994:Recombinant Proteins / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood; D013964:Thyroid Neoplasms / Q000188:drug therapy / Q000378:metabolism; D013965:Thyroidectomy; D013972:Thyrotropin / Q000494:pharmacology; D013974:Thyroxine / Q000627:therapeutic use
D007457:Iodine Radioisotopes; D011989:Receptors, Thyrotropin; D011994:Recombinant Proteins; D013972:Thyrotropin; D000254:Sodium-Potassium-Exchanging ATPase; D013974:Thyroxine