Effects of melatonin on [3H]-thymidine incorporation into DNA of rat thyroid lobes in vitro.
The effects of 4-h incubation in the presence of melatonin and N-acetylserotonin on the incorporation of [3H]-thymidine into DNA of the rat thyroid lobes were investigated. Additionally, thyroid lobes were incubated in the exposure to melatonin with thyrotropin jointly. Melatonin, when applied in the lowest concentration examined (10(-9)M), inhibited [3H]-thymidine incorporation, the effect of other concentrations (10(-6)M-10(-8)M) being not significant. N-acetylserotonin (10(-6)M) did not affect the rate of incorporation of that labelled nucleoside. As expected, thyrotropin enhanced the [3H]-thymidine incorporation into DNA of thyroid lobes. Melatonin (10(-7)M) suppressed that stimulatory effect of thyrotropin. The participation of melatonin in the regulation of thyroid growth processes is considered.
Wajs
E
E
Laboratory of Thyrology, Institute of Endocrinology, University School of Medicine, Lódź, Poland.
Lewiński
A
A
D000818:Animals; D004261:DNA Replication / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007700:Kinetics; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D009924:Organ Culture Techniques; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism*; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism*; D013972:Thyrotropin / Q000494:pharmacology; D014316:Tritium
D014316:Tritium; D012701:Serotonin; D013972:Thyrotropin; D008550:Melatonin; C006389:N-acetylserotonin; D013936:Thymidine