Binding of Aldosterone by Epidermal Cytosol in the Tail of Bullfrog Larvae

Kazutoshi Yamamoto, Sakaé Kikuyama

    Research output: Contribution to journalArticle

    8 Citations (Scopus)

    Abstract

    Characteristics of aldosterone binding by epidermal cytosol in the tail of the larval bullfrog were investigated. Temperature-dependent binding experiments showed that the specific binding of [3H]aldosterone to the tail cytosol was thermolabile. A 3-hr incubation at 0° was the optimum assay condition required for reaching equilibrium. Separation of bound and free hormone was performed using a hydroxylapatite method. Specific binding of aldosterone was observed in the tail epidermis but not in the tail mesenchyme. Saturation analysis revealed that specific binding of [3H]aldosterone to the epidermal cytosol reached maximum between 20 and 40 nM. Scatchard analysis for the cytosol of the tall epidermis yielded a straight line with a dissociation constant (Kd) of 7.0 nM and the maximum number of binding sites (Bmax) of 56.4 fmol/mg protein. Sucrose density gradient analysis of crude cytosol revealed a specific peak of radioactivity in the 8-9 S area. Steroid-binding specificity revealed a significant displacement of the [3H]aldosterone by radioinert aldosterone and, to a lesser extent, by cortisol, whereas 17β-estradiol and testosterone competed very poorly. However, corticosterone and dexamethasone, glucocorticoids in mammals, were better competitors of the aldosterone binding, whereas ZK91587, a selective synthetic antagonist for mineralocorticoid receptor in mammals, scarcely inhibited the aldosterone binding. These results suggest that the aldosterone-binding site may also be a corticosterone receptor and that there may be no other receptors specific for aldosterone at least in the tail epidermis.

    Original languageEnglish
    Pages (from-to)283-290
    Number of pages8
    JournalGeneral and Comparative Endocrinology
    Volume89
    Issue number2
    DOIs
    Publication statusPublished - 1993 Feb

    Fingerprint

    Rana catesbeiana
    aldosterone
    Aldosterone
    cytosol
    Cytosol
    Larva
    Tail
    tail
    larvae
    epidermis (animal)
    Epidermis
    Mammals
    binding sites
    Binding Sites
    Mineralocorticoid Receptor Antagonists
    Mineralocorticoid Receptors
    mammals
    Mesoderm
    Durapatite
    Corticosterone

    ASJC Scopus subject areas

    • Endocrinology

    Cite this

    Binding of Aldosterone by Epidermal Cytosol in the Tail of Bullfrog Larvae. / Yamamoto, Kazutoshi; Kikuyama, Sakaé.

    In: General and Comparative Endocrinology, Vol. 89, No. 2, 02.1993, p. 283-290.

    Research output: Contribution to journalArticle

    Yamamoto, Kazutoshi ; Kikuyama, Sakaé. / Binding of Aldosterone by Epidermal Cytosol in the Tail of Bullfrog Larvae. In: General and Comparative Endocrinology. 1993 ; Vol. 89, No. 2. pp. 283-290.
    @article{f254d477291a48aca41419b288559243,
    title = "Binding of Aldosterone by Epidermal Cytosol in the Tail of Bullfrog Larvae",
    abstract = "Characteristics of aldosterone binding by epidermal cytosol in the tail of the larval bullfrog were investigated. Temperature-dependent binding experiments showed that the specific binding of [3H]aldosterone to the tail cytosol was thermolabile. A 3-hr incubation at 0° was the optimum assay condition required for reaching equilibrium. Separation of bound and free hormone was performed using a hydroxylapatite method. Specific binding of aldosterone was observed in the tail epidermis but not in the tail mesenchyme. Saturation analysis revealed that specific binding of [3H]aldosterone to the epidermal cytosol reached maximum between 20 and 40 nM. Scatchard analysis for the cytosol of the tall epidermis yielded a straight line with a dissociation constant (Kd) of 7.0 nM and the maximum number of binding sites (Bmax) of 56.4 fmol/mg protein. Sucrose density gradient analysis of crude cytosol revealed a specific peak of radioactivity in the 8-9 S area. Steroid-binding specificity revealed a significant displacement of the [3H]aldosterone by radioinert aldosterone and, to a lesser extent, by cortisol, whereas 17β-estradiol and testosterone competed very poorly. However, corticosterone and dexamethasone, glucocorticoids in mammals, were better competitors of the aldosterone binding, whereas ZK91587, a selective synthetic antagonist for mineralocorticoid receptor in mammals, scarcely inhibited the aldosterone binding. These results suggest that the aldosterone-binding site may also be a corticosterone receptor and that there may be no other receptors specific for aldosterone at least in the tail epidermis.",
    author = "Kazutoshi Yamamoto and Saka{\'e} Kikuyama",
    year = "1993",
    month = "2",
    doi = "10.1006/gcen.1993.1034",
    language = "English",
    volume = "89",
    pages = "283--290",
    journal = "General and Comparative Endocrinology",
    issn = "0016-6480",
    publisher = "Academic Press Inc.",
    number = "2",

    }

    TY - JOUR

    T1 - Binding of Aldosterone by Epidermal Cytosol in the Tail of Bullfrog Larvae

    AU - Yamamoto, Kazutoshi

    AU - Kikuyama, Sakaé

    PY - 1993/2

    Y1 - 1993/2

    N2 - Characteristics of aldosterone binding by epidermal cytosol in the tail of the larval bullfrog were investigated. Temperature-dependent binding experiments showed that the specific binding of [3H]aldosterone to the tail cytosol was thermolabile. A 3-hr incubation at 0° was the optimum assay condition required for reaching equilibrium. Separation of bound and free hormone was performed using a hydroxylapatite method. Specific binding of aldosterone was observed in the tail epidermis but not in the tail mesenchyme. Saturation analysis revealed that specific binding of [3H]aldosterone to the epidermal cytosol reached maximum between 20 and 40 nM. Scatchard analysis for the cytosol of the tall epidermis yielded a straight line with a dissociation constant (Kd) of 7.0 nM and the maximum number of binding sites (Bmax) of 56.4 fmol/mg protein. Sucrose density gradient analysis of crude cytosol revealed a specific peak of radioactivity in the 8-9 S area. Steroid-binding specificity revealed a significant displacement of the [3H]aldosterone by radioinert aldosterone and, to a lesser extent, by cortisol, whereas 17β-estradiol and testosterone competed very poorly. However, corticosterone and dexamethasone, glucocorticoids in mammals, were better competitors of the aldosterone binding, whereas ZK91587, a selective synthetic antagonist for mineralocorticoid receptor in mammals, scarcely inhibited the aldosterone binding. These results suggest that the aldosterone-binding site may also be a corticosterone receptor and that there may be no other receptors specific for aldosterone at least in the tail epidermis.

    AB - Characteristics of aldosterone binding by epidermal cytosol in the tail of the larval bullfrog were investigated. Temperature-dependent binding experiments showed that the specific binding of [3H]aldosterone to the tail cytosol was thermolabile. A 3-hr incubation at 0° was the optimum assay condition required for reaching equilibrium. Separation of bound and free hormone was performed using a hydroxylapatite method. Specific binding of aldosterone was observed in the tail epidermis but not in the tail mesenchyme. Saturation analysis revealed that specific binding of [3H]aldosterone to the epidermal cytosol reached maximum between 20 and 40 nM. Scatchard analysis for the cytosol of the tall epidermis yielded a straight line with a dissociation constant (Kd) of 7.0 nM and the maximum number of binding sites (Bmax) of 56.4 fmol/mg protein. Sucrose density gradient analysis of crude cytosol revealed a specific peak of radioactivity in the 8-9 S area. Steroid-binding specificity revealed a significant displacement of the [3H]aldosterone by radioinert aldosterone and, to a lesser extent, by cortisol, whereas 17β-estradiol and testosterone competed very poorly. However, corticosterone and dexamethasone, glucocorticoids in mammals, were better competitors of the aldosterone binding, whereas ZK91587, a selective synthetic antagonist for mineralocorticoid receptor in mammals, scarcely inhibited the aldosterone binding. These results suggest that the aldosterone-binding site may also be a corticosterone receptor and that there may be no other receptors specific for aldosterone at least in the tail epidermis.

    UR - http://www.scopus.com/inward/record.url?scp=0027534512&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=0027534512&partnerID=8YFLogxK

    U2 - 10.1006/gcen.1993.1034

    DO - 10.1006/gcen.1993.1034

    M3 - Article

    C2 - 8454173

    AN - SCOPUS:0027534512

    VL - 89

    SP - 283

    EP - 290

    JO - General and Comparative Endocrinology

    JF - General and Comparative Endocrinology

    SN - 0016-6480

    IS - 2

    ER -