TY - JOUR
T1 - Age-related changes in polyamine biosynthesis after fasting and refeeding
AU - Yoshinaga, Kiego
AU - Ishizuka, Jin
AU - Evers, B. Mark
AU - Townsend, Courtney M.
AU - Thompson, James C.
N1 - Funding Information:
Acknowledgments--Supported by grants from the National Institutes of Health (Nos. 5R37 DK 15241, PO 1 DK 35608, and R29 AG 10885), American Cancer Society (No.CB-571), and Walls Medical Research Foundation. The authors thank Karen Cerdas for her technical assistance and Gene Dockal and Chrissy Gould for their assistance in the preparation of this manuscript.
PY - 1993
Y1 - 1993
N2 - The effect of aging on ornithine decarboxylase (ODC) activity and polyamine biosynthesis in the proximal small intestine was studied in two groups of male Fisher 344 rats (young [4-month old] and aged [26- to 27-month old]) using a fasting and refeeding model. In control (nonfasted) rats, levels of polyamines (putrescine, spermidine and spermine) and ODC activity were significantly higher in aged compared with young rats. In aged rats, fasting significantly reduced the levels of putrescine by 41%, spermidine by 23%, and spermine by 11%; however, fasting had no effect on polyamine levels in young rats. ODC activity was decreased 75% in young and 50% in aged rats after fasting compared with the respective age-matched controls. Conversely, 2 h after reinstituting a chow diet increased ODC activity by 17-fold in young rats but only 8-fold in aged rats. Putrescine levels were also increased in both age groups after refeeding; however, similar to ODC activity, these increases were much less in aged rats. In addition, spermidine and spermine levels remained significantly depressed in the aged groups even after 24 h of refeeding. These findings suggest that the normal rigid control of gut polyamine biosynthesis and proliferation noted in young rats is markedly altered with aging.
AB - The effect of aging on ornithine decarboxylase (ODC) activity and polyamine biosynthesis in the proximal small intestine was studied in two groups of male Fisher 344 rats (young [4-month old] and aged [26- to 27-month old]) using a fasting and refeeding model. In control (nonfasted) rats, levels of polyamines (putrescine, spermidine and spermine) and ODC activity were significantly higher in aged compared with young rats. In aged rats, fasting significantly reduced the levels of putrescine by 41%, spermidine by 23%, and spermine by 11%; however, fasting had no effect on polyamine levels in young rats. ODC activity was decreased 75% in young and 50% in aged rats after fasting compared with the respective age-matched controls. Conversely, 2 h after reinstituting a chow diet increased ODC activity by 17-fold in young rats but only 8-fold in aged rats. Putrescine levels were also increased in both age groups after refeeding; however, similar to ODC activity, these increases were much less in aged rats. In addition, spermidine and spermine levels remained significantly depressed in the aged groups even after 24 h of refeeding. These findings suggest that the normal rigid control of gut polyamine biosynthesis and proliferation noted in young rats is markedly altered with aging.
KW - aging
KW - gut mucosa
KW - ornithine decarboxylase
KW - polyamines
KW - proliferation
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U2 - 10.1016/0531-5565(93)90045-F
DO - 10.1016/0531-5565(93)90045-F
M3 - Article
C2 - 8137893
AN - SCOPUS:0027753789
SN - 0531-5565
VL - 28
SP - 565
EP - 572
JO - Experimental Gerontology
JF - Experimental Gerontology
IS - 6
ER -