Type II thyroxine 5′-deiodinase (5′-D) activity in both pineal and Harderian glands of the Swiss mouse was studied. Pineal 5′-D activity exhibited a nyctohemeral profile with a maximal peak value at 05.00 h, which coincides with that for pineal melatonin production. However, no rhythm of 5′-D activity in the Harderian gland could be found. In pineal gland, light at night inhibited the nocturnal increase in 5′-D activity, while isoproterenol, a β-adrenergic agonist, could not stimulate the enzyme. In the Harderian gland, neither darkness, nor light at night, or isoproterenol were capable of modifying basal values of 5′-D activity.
Nyctohemeral rhythmicity of type II thyroxine 5′-deiodinase activity in the pineal gland but not in the Harderian gland of the Swiss mouse
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A. Rubio, C. Osuna, M. A. Lopez-Gonzalez, R. J. Reiter, J. M. Guerrero; Nyctohemeral rhythmicity of type II thyroxine 5′-deiodinase activity in the pineal gland but not in the Harderian gland of the Swiss mouse. Biosci Rep 1 April 1991; 11 (2): 111–117. doi: https://doi.org/10.1007/BF01119198
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