Chronic food restriction (FR) leads to adaptive cellular changes, some of which retard aging. Moreover, some of these changes occur within weeks after onset of FR. Because neuroendocrine mechanisms may mediate these effects, we measured the effect of FR on the messenger ribonucleicacids (mRNAs) encoding all of the tropic hormones of the anterior pituitary (AP). Slot blot and solution hybridization were conducted on AP ribonucleicacid (RNA) samples obtained at 0500 h (AM) and 1500 h (PM) from 3-month-old male Fischer 344 rats fed ad libitum (AL) or FR (60% of AL calories) since 6 weeks of age. PolyA RNA/μg total RNA was similar in AL and FR rats, indicating that there was no overall effect of FR on mRNA levels. The level of proopiomelanocortin (POMC) mRNA was not reduced by FR when expressed per μg of RNA or as total AP content. By contrast, the total AP content of the mRNAs encoding LHβ, FSHβ, TSHβ, GH, and PRL was markedly reduced by FR. When expressed per μg of RNA, however, only GH (AM and PM), FSHβ (AM), TSHβ (PM), and PRL (PM) were reduced by FR. These results reveal that FR differentially affects pituitary tropic hormone mRNA levels within weeks after onset of FR, and are consistent with a role for neuroendocrine alterations in the initiation of adaptive cellular responses to FR.
|Original language||English (US)|
|Journal||Journals of Gerontology - Series A Biological Sciences and Medical Sciences|
|State||Published - 1998|
ASJC Scopus subject areas
- Geriatrics and Gerontology