title: [Negative feedback in the epiphyseal-thyroid system].
abstract: The negative feedback mechanism in the epiphyseal-thyroid system was studied. The activating thyroxin influence upon hydroxy-indole-O-methyl-transferase, being the main enzyme of melatonin biosynthesis, was found in experimental Wistar rats. The "dose-response" curves were examined at varying times after thyroxin injections. The results obtained confirm the previous data concerning the activating effect of rat chronic hyperthyroidization on hydroxy-indole-O-methyl-transferase and intensified melatonin excretion with the urine in patients with pronounced thyrotoxicosis.
mesh_terms: D000121:Acetylserotonin O-Methyltransferase / Q000378:metabolism; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005246:Feedback; D008297:Male; D008550:Melatonin / Q000096:biosynthesis; D010870:Pineal Gland / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000502:physiology*; D013974:Thyroxine / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000121:Acetylserotonin O-Methyltransferase; D008550:Melatonin; D013974:Thyroxine
vernacular_title: Ob otritsatel'noĭ obratnoĭ sviazi v sisteme épifiz-shchitovidnaia zheleza.