title: An enzyme-linked immunosorbent assay to study human relaxin in human pregnancy and in pregnant rhesus monkeys.
abstract: A sensitive and specific double-antibody enzyme-linked immunoassay, using a synthetic analogue of human relaxin for standard and immunogen, was developed for the measurement of human relaxin (hRLX) in serum and plasma. No cross-reactivity was observed for human insulin, human insulin-like growth factor-I, hGH, human chorionic gonadotropin, hFSH, hLH or human prolactin. The assay was used to monitor RLX concentrations in samples from men, non-pregnant and pregnant women, and in pregnant rhesus monkeys infused with hRLX. RLX was not detected in serum from men nor from non-pregnant women, while a concentration of 600 ng/l was measured in pooled sera from two pregnant women (pregnancies achieved by in-vitro fertilization). Immunoreactive RLX (1.1 micrograms/g) was found in human corpora lutea taken from ectopic pregnancies at 7 weeks. In an experiment with a pregnant rhesus monkey infused with human RLX analogue, less than 1.5% of the maternal concentration was measured in the fetal circulation. Even though preliminary, these data suggest a low level of transfer of human analogue relaxin across the placenta in a rhesus monkey. Further studies of the physiology of RLX in human pregnancy will be facilitated by the availability of this immunoassay.
authors.affiliation: Department of Medicinal and Analytical Chemistry, Genentech Inc., San Francisco, California 94080.
authors.forename: C
authors.initials: C
authors.lastname: Lucas
authors.forename: L N
authors.initials: LN
authors.lastname: Bald
authors.forename: M C
authors.initials: MC
authors.lastname: Martin
authors.forename: R B
authors.initials: RB
authors.lastname: Jaffe
authors.forename: D W
authors.initials: DW
authors.lastname: Drolet
authors.forename: M
authors.initials: M
authors.lastname: Mora-Worms
authors.forename: G
authors.initials: G
authors.lastname: Bennett
authors.forename: A B
authors.initials: AB
authors.lastname: Chen
authors.forename: P D
authors.initials: PD
authors.lastname: Johnston
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D006801:Humans; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D010920:Placenta / Q000502:physiology; D011247:Pregnancy / Q000097:blood*; D012065:Relaxin / Q000097:blood*
chemical_list: D012065:Relaxin