Abstract
We tested the hypothesis that acute restraint stress results in ultrastructural evidence for enhanced release of alpha-melanocyte-stimulating hormone (α-MSH) and β-endorphin from the intermediate lobe (IL) of the rat pituitary. Measurements of plasma α-MSH-and β-endorphin-immunoreactivity (ir) were used to confirm ultrastructural findings. Plasma α-MSH-ir was elevated after 20 and 30 min of restraint while plasma β-endorphin-ir peaked 10 min after the onset of restraint. Ultrastructural analysis revealed a decrease in the content of secretory granules within IL cells of stressed rats. Analysis of Golgi-related immature secretory granules in IL cells indicated that new peptide synthesis was not enhanced after 30 min of restraint. These results confirm previous studies showing and elevation of plasma β-endorphin and α-MSH-ir during acute restraint. Furthermore, these results indicate that quantitative analysis at the ultrastructural level can be used to assess peptide release from IL secretory cells during stress.
Original language | English (US) |
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Pages (from-to) | 589-593 |
Number of pages | 5 |
Journal | Cell and tissue research |
Volume | 261 |
Issue number | 3 |
DOIs | |
State | Published - Sep 1990 |
Externally published | Yes |
Keywords
- Pituitary gland
- Rat (Sprague-Dawley)
- Secretory granules
- Stress
- pars intermedia
- α-MSH
- β-Endorphin
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Histology
- Cell Biology