Photoperiod and temperature effects on adrenal tyrosine hydroxylase and its relation to nonshivering thermogenisis

摘要

Exposure to short photoperiod increased the activity of adrenal tyrosine hydroxylase (TOH). During summer the shortening of photoperiod at constantTaof 23°C stimulated TOH from 7.28 to 10.94 nmolesl-Dopa/(h·pair of adrenals), which was as effective as a chronic exposure to 15°CTa, elevating TOH to 9.1 nmolesl-Dopa/(h·pair of adrenals). The stimulation of TOH by photoperiod or cold exposure in Djungarian hamsters was well correlated with an increase in their ability for nonshivering thermogene