Different binding of stimulatory-type and blocking-type TSH receptor antibody with guinea-pig testis membrane.
A receptor assay using [125I]bTSH-binding to guinea-pig testis membrane was developed. Unlabelled hCG and FSH inhibited [125I]bTSH binding. In patients with Graves' disease and in untreated hyperthyroid patients, almost all long-acting thyroid stimulators and thyroid-stimulating antibodies, respectively did not inhibit [125I]bTSH binding, which on the other hand was inhibited by thyroid stimulation blocking antibodies in patients with primary hypothyroidism. When the inhibitory effect on the binding of [125I]hCG and 125I-synthetic alpha-subunit peptide (alpha 26-46) of hCG to testis membrane was examined, bTSH resulted in a significant inhibition. However, all three kinds of TSH receptor antibodies had no inhibitory effect. This study demonstrated 1. interaction of alpha-subunit of TSH and hCG with the testicular receptor; 2. binding of thyroid stimulation-blocking antibody and lack of binding of thyroid-stimulating antibody to the testicular TSH receptor in spite of binding of these TSH receptor antibodies to the thyroidal TSH receptor, and 3. lack of binding of thyroid-stimulating antibody and thyroid stimulation-blocking antibody to the testicular gonadotropin receptor.
Inui
T
T
Central Clinical Laboratory, Shiga University of Medical Science, Japan.
Ochi
Y
Y
Hachiya
T
T
Chen
W
W
Nakajima
Y
Y
Kajita
Y
Y
Ogura
H
H
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000378:metabolism* / Q000502:physiology; D001323:Autoantibodies / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006168:Guinea Pigs; D018828:Immunoglobulins, Thyroid-Stimulating; D007457:Iodine Radioisotopes; D008135:Long-Acting Thyroid Stimulator / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000187:drug effects / Q000276:immunology; D011869:Radioligand Assay; D011967:Receptors, Gonadotropin / Q000187:drug effects / Q000378:metabolism; D011989:Receptors, Thyrotropin / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D013737:Testis / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D013961:Thyroid Gland / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D013972:Thyrotropin / Q000276:immunology / Q000378:metabolism
D000906:Antibodies; D001323:Autoantibodies; D006063:Chorionic Gonadotropin; D018828:Immunoglobulins, Thyroid-Stimulating; D007457:Iodine Radioisotopes; D011967:Receptors, Gonadotropin; D011989:Receptors, Thyrotropin; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D008135:Long-Acting Thyroid Stimulator