title: A homologous radioreceptor assay for rat follicle-stimulating hormone.
abstract: A homologous radioreceptor assay (RRA) for rat FSH (rFSH), which is both sensitive and easy to perform, is described. The receptor preparation is isolated from a 12,000 X G pellet of rat testes homogenate prepared with a high speed tissue grinder using Tris buffer. The sensitivity of the assay extends below 10 ng rFSH RP-1 (approximately 0.13 ng purified I-3 rat FSH), and the range of the assay spans 2 orders of magnitude. The specific binding of the [125I]rFSH tracer is 22-28% of the total tracer added. Such binding, which exceeds previously published values by 2- to 4-fold, allows the addition of relatively small amounts of total tracer radioactivity, which, in turn, contributes to a low nonspecific binding and highly reproducible values for replicates (coefficient of variation, approximately 3.0%). This represents the first homologous RRA for rFSH using testicular receptors. Likewise, the sensitivity and reproducibility exceed those of previous RRAs for rFSH.
mesh_terms: D000818:Animals; D005640:Follicle Stimulating Hormone / Q000032:analysis* / Q000378:metabolism; D007457:Iodine Radioisotopes; D008297:Male; D010710:Phosphates / Q000494:pharmacology; D011869:Radioligand Assay / Q000379:methods* / Q000592:standards; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000302:isolation & purification; D011962:Receptors, FSH; D013045:Species Specificity; D013737:Testis / Q000032:analysis
chemical_list: D007457:Iodine Radioisotopes; D010710:Phosphates; D011956:Receptors, Cell Surface; D011962:Receptors, FSH; D005640:Follicle Stimulating Hormone