title: Thyroid hormone in biological rhythms.
abstract: An essential role for thyroid hormone in the production of biological rhythms is proposed. In order for a system to oscillate it must have two stable states. It is possible that thyroid hormone alters the concentration of substrate and product in such a way that the system moves cyclically between these two states. Experimental evidence and clinical facts are invoked to complement the theoretical considerations.
mesh_terms: D000305:Adrenal Cortex Hormones / Q000097:blood; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D001683:Biological Clocks; D002784:Cholesterol / Q000096:biosynthesis; D002940:Circadian Rhythm; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007037:Hypothyroidism / Q000378:metabolism; D008280:Magnetics; D008297:Male; D008798:Mevalonic Acid / Q000097:blood; D051381:Rats; D013963:Thyroid Hormones / Q000502:physiology*; D013974:Thyroxine / Q000494:pharmacology
chemical_list: D000305:Adrenal Cortex Hormones; D013963:Thyroid Hormones; D000324:Adrenocorticotropic Hormone; D002784:Cholesterol; D013974:Thyroxine; D008798:Mevalonic Acid; D006854:Hydrocortisone