Newt prolactin and its involvement in reproduction

S. Kikuyama*, T. Yazawa, S. Abe, K. Yamamoto, T. Iwata, K. Hoshi, I. Hasunuma, G. Mosconi, A. M. Polzonetti-Magni

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    23 Citations (Scopus)


    The amino acid sequence of newt (Cynops pyrrhogaster) prolactin deduced from the nucleotide sequence of its cDNA showed a relatively high homology with sequences of chicken and sea turtle prolactins as well as with those of anuran prolactins. Cynops prolactin receptor transcripts were detected in various tissues and organs, suggesting that prolactin plays multiple roles in urodeles. Urodele prolactin was purified from the pituitaries of C. pyrrhogaster. Antiserum against this prolactin was used for radioimmunoassay of plasma prolactin and immunoneutralization experiments. Endogenous prolactin was shown to induce migration to water, courtship behavior, and cessation of spermatocytogenesis in the Cynops newt. The hormone was found to be involved in the development of cloacal glands such as the lateral and abdominal glands, growth of the tail and Mauthner neurons, secretion of oviducal jelly, and enhanced synthesis of a female attracting pheromone (sodefrin), and responsiveness of the olfactory epithelium to sodefrin. In most of these cases, prolactin was found to act synergistically or antagonistically with sex steroids. We also discovered that hypersecretion of prolactin in the newts subjected to cold temperature was induced by hypothalamic stimulation rather than release from hypothalamic inhibition.

    Original languageEnglish
    Pages (from-to)984-993
    Number of pages10
    JournalCanadian Journal of Physiology and Pharmacology
    Issue number12
    Publication statusPublished - 2000


    • Newts
    • Prolactin
    • Reproduction

    ASJC Scopus subject areas

    • Physiology
    • Pharmacology


    Dive into the research topics of 'Newt prolactin and its involvement in reproduction'. Together they form a unique fingerprint.

    Cite this