Abstract
The influence of aging on the molecular forms of endorphins in the hypothalamus of rats was investigated. Extracts of individual hypothalami from 8- and 24-month-old male Fischer 344 rats were subjected to high-performance liquid chromatography. Eluate fractions were assayed for β-endorphin-like immunoreactivity (βE-LI) and γ-endorphin-like immunoreactivity (γE-LI). Hypothalami from adult (8-month-old) rats contained predominantly β-endorphin-1-31 with smaller amounts of β-endorphin-1-27 and 1-26. Only 5% of the βE-LI co-eluted with α-N-acetylated forms of β-endorphin. In hypothalamic extracts from old rats more than 30% of the βE-LI co-eluted with acetylated forms of β-endor-phin and over 35% of the βE-LI co-eluted with acetylated or unacetylated β-endorphin-1-26. The individual elution profiles of βE-LI were also much more variable among the old rats than among the adult rats. More than 80% of the γE-LI from adult rat extracts co-eluted with γ-endorphin (β-endorphin-1-17) and less than 3% with α-N-acetyl-γ-endorphin. In contrast, more than 35% of the γE-LI from old rat hypothalami was present in the acetylated form. These results suggest that significant alterations in post-translational processing of peptides may occur in neuropeptide systems during aging.
Original language | English (US) |
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Pages (from-to) | 124-131 |
Number of pages | 8 |
Journal | Neuroendocrinology |
Volume | 43 |
Issue number | 2 |
DOIs | |
State | Published - 1986 |
Externally published | Yes |
Keywords
- Aging
- Fischer 344 rats
- Hypothalamus
- N-acetylation
- β-Endorphin
- γ-Endorphin
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Endocrinology
- Endocrine and Autonomic Systems
- Cellular and Molecular Neuroscience