title: Directly iodinated rat relaxin as a tracer for use in radioimmunoassays.
abstract: A newly developed, specific, sensitive and reliable RIA for rat relaxin is described. Radioiodinated rat relaxin, with a specific activity of 22 to 37 kBq/micrograms, was prepared from purified authentic ovarian rat relaxin using the chloramine T method. Polyclonal rat relaxin antiserum was raised in rabbits. Assay sensitivity was 30 pg/tube. Intra- and interassay coefficients of variation were 8% and 13%, respectively. Initial experiments demonstrated rising concentrations of rat relaxin in pregnant rats. Serum of adult male or non-pregnant female rats contained undetectable levels of rat relaxin. The assay is suitable for measurements of rat relaxin in biological fluids, thus making the assay a valuable tool for further studies on the physiology of relaxin.
authors.affiliation: Division of Endocrinology, Harbor-UCLA Medical Center, Torrance.
authors.forename: F
authors.initials: F
authors.lastname: Jockenhövel
authors.forename: M A
authors.initials: MA
authors.lastname: Peterson
authors.forename: P D
authors.initials: PD
authors.lastname: Johnston
authors.forename: R S
authors.initials: RS
authors.lastname: Swerdloff
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D011247:Pregnancy / Q000097:blood; D011863:Radioimmunoassay / Q000379:methods*; D051381:Rats; D012065:Relaxin / Q000032:analysis* / Q000097:blood / Q000302:isolation & purification; D012661:Semen / Q000737:chemistry
chemical_list: D007457:Iodine Radioisotopes; D012065:Relaxin