|
| << vorige | volgende >> |
Tijdschrift beschrijving
Alle jaargangen van het bijbehorende tijdschrift
Alle afleveringen van het bijbehorende jaargang
Alle artikelen van de bijbehorende aflevering
Details van artikel 4 van 7 gevonden artikelen
| Titel: |
Effects of environmental temperature on the circadian periodicity of hepatic enzymes in mice |
| Auteur: |
Francesconi, R. P. Mager, M. |
| Verschenen in: |
Biological rhythm research |
| Paginering: | Jaargang 1 (1970) nr. 3 pagina's 239-250 |
| Jaar: |
1970-11 |
| Inhoud: |
The exposure of naive mice to cold (2°C) for 6 hours resulted in a 10-fold increase in the specific activity of hepatic tyrosine aminotransferase (TAT) and a 2-fold rise in tryptophan oxygenase (TO). These changes altered the circadian periodicities of the enzymes, although after 36-48 hours the reestablishment of diurnal rhythms was again discerned for both; however, the minimal and maximal levels for TAT remained significantly elevated for at least two weeks. Adrenalectomy prior to the cold stress prevented the rise in TO yet was ineffective in attenuating the induction of TAT. Large doses of actinomycin D obliterated the increase in TO, and significantly reduced the TAT response. Alternatively, acute heat (36°C) exposure had no effect upon the activity level or circadian periodicity of either enzyme, and neither cold nor heat affected their hormonal or substrate induction. Cold exposure elicits a hormonal response manifested in acute increases in the activity of both enzymes. The reestablishment of periodicities in the cold and the absence of alterations in the heat indicate a basic difference in the response of both hepatic enzymes to these environmental Stressors, as well as a difference in the mechanism for their regulation in the cold. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 4 van 7 gevonden artikelen
| << vorige | volgende >> |