Development and Application of a Homologous Radioimmunoassay for Xenopus Prolactin

Kazutoshi Yamamoto*, Kaoru Yamashita, Yasuyuki Hayakawa, Yoichi Hanaoka, Sakae Kikuyama

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    9 Citations (Scopus)


    A specific and sensitive homologous radioimmunoassay (RIA) for Xenopus prolactin (xPRL) was developed. PRL isolated from X. laevis pituitary glands was used for generating antiserum in a rabbit, for radioligand and for the standard. Pituitary homogenates and plasma from adult Xenopus produced displacement curves parallel to the xPRL standard. Plasma from hypophysectomized Xenopus showed negligible cross-reactivity. Purified PRLs from other amphibian species such as the bullfrog (Rana catesbeiana) and toad (Bufo japonicus) gave inhibition curves which did not parallel the standard. Ovine PRL, mouse PRL, newl (Cynops pyrrhogaster) PRL, bullfrog GH, and bullfrog LH showed no inhibition of binding even at relatively high doses in this RIA. The sensitivity of the RIA was 0.122 ± 0.005 ng xPRL/100 μl assay buffer. Intraassay and interassay coefficients of variation were 2.46 and 6.65%, respectively. Histological studies of Xenopus adenohypophyses revealed that the cells which reacted immunologically with the antiserum against xPRL corresponded to those positively stained with antiserum against bullfrog PRL. A preliminary application of this homologous RIA for xPRL was performed by evaluating plasma and pituitary PRL levels in subadult and adult Xenopus of both sexes.

    Original languageEnglish
    Pages (from-to)28-34
    Number of pages7
    JournalGeneral and Comparative Endocrinology
    Issue number1
    Publication statusPublished - 1995 Jul

    ASJC Scopus subject areas

    • Endocrinology


    Dive into the research topics of 'Development and Application of a Homologous Radioimmunoassay for Xenopus Prolactin'. Together they form a unique fingerprint.

    Cite this