GABA uptake is inhibited by thyroid hormones: implications for depression.
Studies of the effects of thyroid hormones on the uptake of neurotransmitters by homogenates of rat cerebral cortex have revealed a significant competitive inhibition of neuronal uptake of [3H]GABA by thyroid hormones (T3 greater than T4 greater than rT3). The IC50 for inhibition of GABA uptake by T3 was estimated at 4 microM and that of T4 at 11 microns. GABA uptake in homogenates of cerebral cortex from hypothyroid rats was significantly enhanced over that of controls; however, uptake in tissues from hyperthyroid rats was not significantly diminished.
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D003864:Depression, Chemical; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013963:Thyroid Hormones / Q000494:pharmacology*; D013974:Thyroxine / Q000494:pharmacology; D014284:Triiodothyronine / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018377:Neurotransmitter Agents; D013963:Thyroid Hormones; D014284:Triiodothyronine; D005680:gamma-Aminobutyric Acid; D013974:Thyroxine