Quantitation of human chorionic gonadotrophin (hCG) by radioreceptor assay.
A sensitive radioreceptor assay was developed for pharmaceutical preparations of human chorionic gonadotrophin with the use of rat testicular membranes as receptor preparation and human 125I-chorionic gonadotrophin as tracer. The addition of unlabelled human chorionic gonadotrophin or luteinizing hormone inhibited the binding of 125I-chorionic gonadotrophin to the receptors in a concentration dependent way. Concentrations of human chorionic gonadotrophin between 30-300 mIU ml(-1) were normally used for a three-dose assay fulfilling pharmacopoeial statistical requirements for assay validity. The relative standard deviation for five assays was 7%. Estimates of potency of commercial preparations of human chorionic gonadotrophin obtained with the radioreceptor assay correlated well with corresponding estimates from in vivo assays. The proposed radioreceptor assay, however, provides a considerable saving in the number of animals required, requires less technical support, and is more precise than the in vivo method.
Sjödin
L
L
Department of Drugs, National Board of Health and Welfare, Uppsala, Sweden.
Dahlén
H
H
Erlandsson-Persson
K
K
Henningsson
A C
AC
Viitanen
E
E
D000818:Animals; D001667:Binding, Competitive; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical / Q000592:standards; D006063:Chorionic Gonadotropin / Q000032:analysis* / Q000378:metabolism / Q000592:standards; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008566:Membranes / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D011955:Receptors, Drug / Q000378:metabolism; D013737:Testis / Q000378:metabolism
D006063:Chorionic Gonadotropin; D007457:Iodine Radioisotopes; D011955:Receptors, Drug