ISSN:
1432-0878
Keywords:
Pituitary gland
;
pars intermedia
;
Stress
;
Secretory granules
;
α-MSH
;
β-Endorphin
;
Rat (Sprague-Dawley)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00313539
