[Studies on radioimmunoassays of TSH subunits (author's transl)].
In order to establish radioimmunoassay (RIA) systems for the determination of TSH subunits were carried out. Standard TSH supplied from MRC and standard TSH subunits from Calbiochem were identified to be highly purified by gel filtrations through a Sephadex G-100 column. Antibodies of TSH subunits supplied from Calbiochem bound to standard TSH subunits but not to other pituitary hormones except for TSH. Cross reactivity of anti TSH-alpha antibody to standard TSH was 0.000082, and that of TSH-beta to standard TSH was 0.000011. As the standard curve of each subunit and the displacement curve by TSH were parallel in each assay system, serum levels of TSH subunits were computed by the subtraction of the amount of TSH subunits which was overestimated by the cross reaction with native TSH in this assay system. Cross reactivity of anti TSH-alpha antibody to TSH-beta was 0.001, and that of anti TSH-beta antibody to TSH-alpha was 0.002. But in clinical studies, one TSH subunit was not greatly affected by the determination of another TSH subunit. Utilizing these standard TSH subunits, antibodies of TSH subunits and 125I-labelled TSH subunits obtained by the chloramine-T method, the RIA systems for measurement of serum TSH subunits levels without an extraction procedure were developed. In each RIA system of TSH subunit, a good dose response curve was observed in the range from 0.2 to 50 ng/ml of TSH subunits. Recovery and reproducibility of each RIA system were satisfactory. The serum levels of TSH subunits in 13 normal subjects, 12 patients with primary hypothyroidism and 7 patients with hyperthyroidism were determined by the RIA of TSH subunits. In 13 normal subjects, serum levels of TSH-alpha varied from an undetectable level (U.D.: less than 0.2 ng/ml) to 0.3 ng/ml, and those of TSH-beta varied from an undetectable level (U.D.: less than 0.2 ng/ml) to 0.8 ng/ml. In 12 patients with primary hypothyroidism, serum levels of TSH-alpha varied from U.D. to 4.9 ng/ml, and those of TSH-beta varied from U.D. to 13.6 ng/ml. In 7 patients with hyperthyroidism, serum levels of TSH-alpha varied from U.D. to 4.3 ng/ml, and those of TSH-beta were ranged U.D. From the above data, it is suggested that the direct RIA of serum TSH subunits is a useful tool for studying the roles of TSH subunits in peripheral blood.
D000328:Adult; D000906:Antibodies / Q000032:analysis; D003429:Cross Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay / Q000379:methods*; D013972:Thyrotropin / Q000097:blood* / Q000276:immunology / Q000592:standards
D000906:Antibodies; D013972:Thyrotropin