title: Effects of pineal-derived indolic compounds and of certain neuropeptides on the growth processes in the thyroid gland.
abstract: The aim of the present study was to examine the effects of melatonin (Mel) and of pinealectomy (PX) [in a long-term experiment in vivo - 10 weeks], as well as of Mel and N-acetylserotonin (NAc-5HT) [in experiments ex vivo in vitro and in vitro], on the rat thyroid growth processes. Additionally, the incubations in vitro of rat thyroid lobes with 3H-thymidine, in the presence of TSH, vasoactive intestinal polypeptide (VIP), VIP-antagonist ([4Cl-D-Ph6, Leu17]VIP), somatostatin (SS), all the substances used separately or jointly in combinations, were performed. It was shown that: (a) Mel--administered in late afternoon injections--decreased, while PX increased examined indices of thyroid growth in vivo, (b) Mel--administered in s.c. implanted pellets--reversed the inhibitory effect of Mel injections, (c) in experiments ex vivo in vitro and in vitro, the inhibitory effect of Mel revealed only for the lowest applied dose/concentration of the hormone, (d) NAc-5HT showed no effect, (e) VIP decreased 3H-thymidine incorporation into DNA of thyroid lobes in vitro and enhanced the inhibitory effect of SS on the process in question, (f) VIP-antagonist failed to reverse the inhibitory action of VIP on the thyroid growth.
authors.affiliation: Laboratory of Thyroidology, Institute of Endocrinology, University School of Medicine, Lódź, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Lewiński
authors.forename: E
authors.initials: E
authors.lastname: Wajs
authors.forename: M
authors.initials: M
authors.lastname: Karbownik
mesh_terms: D000818:Animals; D004247:DNA / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D008550:Melatonin / Q000494:pharmacology; D008938:Mitosis / Q000187:drug effects; D009479:Neuropeptides / Q000494:pharmacology*; D010870:Pineal Gland / Q000737:chemistry / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D013972:Thyrotropin / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology
chemical_list: D007211:Indoles; D009479:Neuropeptides; D012701:Serotonin; D014660:Vasoactive Intestinal Peptide; D013972:Thyrotropin; D004247:DNA; D008550:Melatonin; C006389:N-acetylserotonin; D013936:Thymidine