Effect of 17 beta-estradiol on the generation time of old cells of the yeast Saccharomyces cerevisiae.
The duration of unbudded period of the yeast Saccharomyces cerevisiae is known to be extended with age from unresolved causes; in this experiment the unbudded period of 20-generation-old cells was extended to be 1.6 times that of 6-generation-old cells. We found that the addition of 17 beta-estradiol into the culture medium reduced the age-related extension of the unbudded period reaching 1.35 times that of the young cells which was unaffected by the hormone. This effect of 17 beta-estradiol was not observed when the old cells were cultured in a glycerol-based medium instead of a glucose-based medium suggesting that the action of 17 beta-estradiol was mediated by facilitation of glycolysis. The administration of 17 beta-estradiol equally elevated the cAMP level of the old cells in either medium up to the level of the young cells but elevated the ATP level of only those in the glucose-based medium. Furthermore, the administration of cAMP shortens the unbudded period of the old cells cultured in the glucose-based medium. Therefore, it was suggested that 17 beta-estradiol causes the shortening of the unbudded period of the old cells by stimulating the energy metabolism through elevation of the cAMP level.
Motizuki
M
M
Department of Biochemistry, Yamanashi Medical College, Japan.
Tsurugi
K
K
D000255:Adenosine Triphosphate / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects*; D016922:Cellular Senescence; D000242:Cyclic AMP / Q000378:metabolism / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology*; D006019:Glycolysis; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000502:physiology*
D004958:Estradiol; D000255:Adenosine Triphosphate; D000242:Cyclic AMP