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Diurnal rhythm of hypophyseal cells in mich. II. Pars intermedia

Acta Biologica Academiae Scientiarum Hungaricae
|January 1, 1979
PubMed

Insights

The pars intermedia of the mouse hypophysis exhibits diurnal rhythmicity in nuclear volume and vacuole formation within lead hematoxylin (PbH)-positive and periodic acid-Schiff (PAS)-positive cells. These cellular changes vary between sexes and throughout the light-dark cycle.

Area of Science:

  • Endocrinology
  • Cell Biology
  • Chronobiology

Background:

  • The pars intermedia of the hypophysis plays a role in hormone secretion.
  • Cellular characteristics within the pars intermedia may exhibit temporal variations.
  • Understanding diurnal rhythms is crucial for interpreting physiological processes.

Purpose of the Study:

  • To investigate diurnal rhythmicity in cellular morphology of the mouse hypophysis pars intermedia.
  • To differentiate and analyze PbH-positive and PAS-positive cells.
  • To compare nuclear volume and vacuole formation between sexes.

Main Methods:

  • Utilized Mac Conaill's lead hematoxylin and periodic acid-Schiff (PAS) staining techniques.
  • Distinguished PbH-positive and PAS-positive cells in the pars intermedia.
  • Quantified nuclear volume and counted nuclear vacuoles in male and female mice under a 12h light/12h dark cycle.

Main Results:

  • Both PbH-positive and PAS-positive cells showed distinct diurnal rhythms in nuclear volume and vacuole number.
  • Maximum nuclear volume in PbH-positive cells occurred at 1800h, minimum at 2400h.
  • PAS-positive cells displayed sex-specific rhythms in nuclear volume and vacuole counts, with notable differences between males and females.

Conclusions:

  • The pars intermedia of the mouse hypophysis exhibits significant diurnal rhythmicity in cellular characteristics.
  • Nuclear volume and vacuole formation are influenced by the time of day and sex.
  • These findings highlight the dynamic nature of the hypophysis and its response to circadian cycles.

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