Maturation of the hypothalamo-pituitary-gonadal axis of male syrian hamsters

Henryk Urbanski, A. Doan, M. Pierce, W. H. Fahrenbach, P. M. Collins

    Research output: Contribution to journalArticle

    21 Citations (Scopus)

    Abstract

    Light-microscope immunocytochemistry (ICC) was used to investigate postnatal changes in the morphology of LHRH neurons in the brains of male Syrian hamsters and to relate these changes to more overt maturational developments within the hypothalamo-pituitary-gonadal axis. The animals were maintained under long-day photoperiods (14L:10D), and groups of 6-7 were killed at 10-day intervals from Day 15 to Day 65. Their brains were fixed with 4% paraformaldehyde, sectioned sagittally with a vibratome (75 μm), and processed for ICC using monoclonal LHRH antibody HU4H. Throughout the study period, the hamsters showed a progressive increase in plasma gonadotropin levels, closely followed by an increase in testicular weight and plasma testosterone levels. Histology of the testes revealed that spermatogenesis was already qualitatively completed by Day 35 and quantitative aspects were established by Day 45. Within the brain, LHRH neuronal perikarya were distributed primarily in the medial septal-preoptic area and the diagonal band of Broca; morphologically, these immunopositive neurons were either monopolar or bipolar. The total number of LHRH neurons detected in the areas examined was approximately 440 throughout the developmental period, and the relative proportions of monopolar and bipolar subtypes (86% and 14%, respectively) remained unchanged. In contrast, the area of the perikarya, as determined by autoimage analysis, showed a highly significant age-related increase, both for the monopolar and bipolar neurons. It is suggested that these developmental changes in the LHRH neurons reflect an increase in LHRH synthesis and may, therefore, provide a neuroendocrine trigger for the onset of puberty.

    Original languageEnglish (US)
    Pages (from-to)991-996
    Number of pages6
    JournalBiology of Reproduction
    Volume46
    Issue number6
    DOIs
    StatePublished - 1992

    Fingerprint

    Mesocricetus
    Gonadotropin-Releasing Hormone
    Neurons
    Brain
    Immunohistochemistry
    Diagonal Band of Broca
    Septum of Brain
    Preoptic Area
    Photoperiod
    Spermatogenesis
    Puberty
    Gonadotropins
    Cricetinae
    Testosterone
    Testis
    Histology
    Monoclonal Antibodies
    Light
    Weights and Measures

    ASJC Scopus subject areas

    • Cell Biology
    • Developmental Biology
    • Embryology

    Cite this

    Maturation of the hypothalamo-pituitary-gonadal axis of male syrian hamsters. / Urbanski, Henryk; Doan, A.; Pierce, M.; Fahrenbach, W. H.; Collins, P. M.

    In: Biology of Reproduction, Vol. 46, No. 6, 1992, p. 991-996.

    Research output: Contribution to journalArticle

    Urbanski, Henryk ; Doan, A. ; Pierce, M. ; Fahrenbach, W. H. ; Collins, P. M. / Maturation of the hypothalamo-pituitary-gonadal axis of male syrian hamsters. In: Biology of Reproduction. 1992 ; Vol. 46, No. 6. pp. 991-996.
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