| Abstract: | The effects of pinealectomy on plasma T3, T4 and free T4 concentrations were studied for about 10 weeks in pigeons maintained either under a constant short photophase or in a regime where a long photophase was replaced by a short one during the experiments. The results indicate that, regardless of the photoperiod, no clear functional relationship can be found between the avian pineal gland and thyroid function, although a transitory increase in T4 levels was seen in both pinealectomized and sham-operated birds shortly after the operations. |
