Lactation decreases angiotensinogen mRNA expression in the midcaudal arcuate nucleus of the rat brain

Robert C. Speth, M (Susan) Smith, Kevin Grove

    Research output: Contribution to journalArticle

    10 Citations (Scopus)

    Abstract

    In lactating rats, ANG II receptor binding in the arcuate nucleus (ARH) and median eminence is decreased. To further evaluate brain angiotensinergic activity during lactation, we assessed angiotensinogen (AON) mRNA by in situ hybridization in forebrains of day 10 or 11 postpartum lactating and diestrous rats. AON mRNA was abundantly expressed in the ARH, preoptic, suprachiasmatic, supraoptic, paraventricular, and dorsomedial hypothalamic nuclei, and other regions, similar to that reported in male rat brains. AON mRNA levels were decreased 27% in the midcaudal ARH of lactating rats but did not differ between lactating or diestrous rats in any of the other brain areas examined. Immunofluorescence for AON and glial fibrillary acidic protein or tyrosine hydroxylase confirmed that the AON immunoreactivity in the ARH was limited to astrocytes. Confocal microscopy revealed close appositions of AON-positive astrocytes to dopaminergic neurons in the ARH. The decrease in AON mRNA in the midcaudal ARH during lactation coupled with decreased ARH ANG II receptor binding suggests that lactating rats are less subject to ANG II-mediated inhibition of prolactin secretion.

    Original languageEnglish (US)
    JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
    Volume280
    Issue number4 49-4
    StatePublished - 2001

    Fingerprint

    Angiotensinogen
    Arcuate Nucleus of Hypothalamus
    Lactation
    Messenger RNA
    Brain
    Astrocytes
    Dorsomedial Hypothalamic Nucleus
    Median Eminence
    Paraventricular Hypothalamic Nucleus
    Dopaminergic Neurons
    Glial Fibrillary Acidic Protein
    Tyrosine 3-Monooxygenase
    Prosencephalon
    Confocal Microscopy
    Prolactin
    Postpartum Period
    In Situ Hybridization
    Fluorescent Antibody Technique

    Keywords

    • Astrocytes
    • Hypothalamus
    • In situ hybridization histochemistry
    • Prolactin secretion
    • Tuberoinfundibular dopamine neurons

    ASJC Scopus subject areas

    • Physiology
    • Physiology (medical)

    Cite this

    Lactation decreases angiotensinogen mRNA expression in the midcaudal arcuate nucleus of the rat brain. / Speth, Robert C.; Smith, M (Susan); Grove, Kevin.

    In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 280, No. 4 49-4, 2001.

    Research output: Contribution to journalArticle

    @article{9f53924d8a054bfead4598cf33812f90,
    title = "Lactation decreases angiotensinogen mRNA expression in the midcaudal arcuate nucleus of the rat brain",
    abstract = "In lactating rats, ANG II receptor binding in the arcuate nucleus (ARH) and median eminence is decreased. To further evaluate brain angiotensinergic activity during lactation, we assessed angiotensinogen (AON) mRNA by in situ hybridization in forebrains of day 10 or 11 postpartum lactating and diestrous rats. AON mRNA was abundantly expressed in the ARH, preoptic, suprachiasmatic, supraoptic, paraventricular, and dorsomedial hypothalamic nuclei, and other regions, similar to that reported in male rat brains. AON mRNA levels were decreased 27{\%} in the midcaudal ARH of lactating rats but did not differ between lactating or diestrous rats in any of the other brain areas examined. Immunofluorescence for AON and glial fibrillary acidic protein or tyrosine hydroxylase confirmed that the AON immunoreactivity in the ARH was limited to astrocytes. Confocal microscopy revealed close appositions of AON-positive astrocytes to dopaminergic neurons in the ARH. The decrease in AON mRNA in the midcaudal ARH during lactation coupled with decreased ARH ANG II receptor binding suggests that lactating rats are less subject to ANG II-mediated inhibition of prolactin secretion.",
    keywords = "Astrocytes, Hypothalamus, In situ hybridization histochemistry, Prolactin secretion, Tuberoinfundibular dopamine neurons",
    author = "Speth, {Robert C.} and Smith, {M (Susan)} and Kevin Grove",
    year = "2001",
    language = "English (US)",
    volume = "280",
    journal = "American Journal of Physiology - Renal Fluid and Electrolyte Physiology",
    issn = "1931-857X",
    publisher = "American Physiological Society",
    number = "4 49-4",

    }

    TY - JOUR

    T1 - Lactation decreases angiotensinogen mRNA expression in the midcaudal arcuate nucleus of the rat brain

    AU - Speth, Robert C.

    AU - Smith, M (Susan)

    AU - Grove, Kevin

    PY - 2001

    Y1 - 2001

    N2 - In lactating rats, ANG II receptor binding in the arcuate nucleus (ARH) and median eminence is decreased. To further evaluate brain angiotensinergic activity during lactation, we assessed angiotensinogen (AON) mRNA by in situ hybridization in forebrains of day 10 or 11 postpartum lactating and diestrous rats. AON mRNA was abundantly expressed in the ARH, preoptic, suprachiasmatic, supraoptic, paraventricular, and dorsomedial hypothalamic nuclei, and other regions, similar to that reported in male rat brains. AON mRNA levels were decreased 27% in the midcaudal ARH of lactating rats but did not differ between lactating or diestrous rats in any of the other brain areas examined. Immunofluorescence for AON and glial fibrillary acidic protein or tyrosine hydroxylase confirmed that the AON immunoreactivity in the ARH was limited to astrocytes. Confocal microscopy revealed close appositions of AON-positive astrocytes to dopaminergic neurons in the ARH. The decrease in AON mRNA in the midcaudal ARH during lactation coupled with decreased ARH ANG II receptor binding suggests that lactating rats are less subject to ANG II-mediated inhibition of prolactin secretion.

    AB - In lactating rats, ANG II receptor binding in the arcuate nucleus (ARH) and median eminence is decreased. To further evaluate brain angiotensinergic activity during lactation, we assessed angiotensinogen (AON) mRNA by in situ hybridization in forebrains of day 10 or 11 postpartum lactating and diestrous rats. AON mRNA was abundantly expressed in the ARH, preoptic, suprachiasmatic, supraoptic, paraventricular, and dorsomedial hypothalamic nuclei, and other regions, similar to that reported in male rat brains. AON mRNA levels were decreased 27% in the midcaudal ARH of lactating rats but did not differ between lactating or diestrous rats in any of the other brain areas examined. Immunofluorescence for AON and glial fibrillary acidic protein or tyrosine hydroxylase confirmed that the AON immunoreactivity in the ARH was limited to astrocytes. Confocal microscopy revealed close appositions of AON-positive astrocytes to dopaminergic neurons in the ARH. The decrease in AON mRNA in the midcaudal ARH during lactation coupled with decreased ARH ANG II receptor binding suggests that lactating rats are less subject to ANG II-mediated inhibition of prolactin secretion.

    KW - Astrocytes

    KW - Hypothalamus

    KW - In situ hybridization histochemistry

    KW - Prolactin secretion

    KW - Tuberoinfundibular dopamine neurons

    UR - http://www.scopus.com/inward/record.url?scp=0034995857&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=0034995857&partnerID=8YFLogxK

    M3 - Article

    VL - 280

    JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

    JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

    SN - 1931-857X

    IS - 4 49-4

    ER -