ABSTRACT
This study was conducted to determine if an oral squamous cell carcinoma alters mRNA expression of serotonin transporter (5-HTT) in the central nervous system. KB cell line derived from a human oral squamous cell carcinoma was inoculated into nude mice, and mRNA expression level of 5-HTT in the dorsal raphe nucleus (DRN) was examined by in situ hybridization when the tumor mass reached to -10% of total body weight. Plasma leptin levels were determined by radioimmunoassay method using a commercial kit. 5-HTT mRNA level was significantly decreased in the DRN of tumor bearing mice, compared to the age-matching non-tumor control. Plasma leptin level decreased concomitantly in tumor bearing mice. These results suggest that oral carcinoma may suppress 5-HTT gene expression in the central nervous system, perhaps in relation with decreased plasma leptin level.
Subject(s)
Animals , Humans , Male , Mice , Body Weight , Carcinoma, Squamous Cell/metabolism , DNA, Complementary , Gene Expression Regulation, Neoplastic , Leptin/blood , Membrane Glycoproteins/genetics , Membrane Transport Proteins/genetics , Mice, Inbred BALB C , Mice, Nude , Mouth Neoplasms/metabolism , Nerve Tissue Proteins/genetics , RNA, Messenger/metabolism , Radioimmunoassay , Raphe Nuclei/metabolism , Serotonin/metabolismABSTRACT
A partir da síntese da serotonina, em 1951, iniciou-se a investigaçäo farmacológica dos receptores serotoninérgicos. A estimulaçäo dos mais variados tipos de receptores gera múltiplas respostas funcionais verificadas em nível de sistema nervoso central, terminaçöes nervosas serotoninérgicos em nível metabólico e fisiopatológico
Subject(s)
Humans , Animals , Rats , In Vitro Techniques , Receptors, Serotonin/drug effects , Receptors, Serotonin/metabolism , Receptors, Serotonin/physiology , Serotonin/metabolism , Enterochromaffin Cells/metabolism , Selective Serotonin Reuptake Inhibitors/pharmacology , Raphe Nuclei , Raphe Nuclei/metabolism , Serotonin Antagonists/pharmacokinetics , Serotonin Antagonists/pharmacology , Serotonin Receptor Agonists/pharmacology , Serotonin/pharmacology , VasoconstrictionABSTRACT
The aim of this study was to investigate whether D-fenfluramine (FEN) releases 5-hydroxytryptamine (5-HT) selectively from dorsal raphe (DR) terminais. Male Wistar rats, 180-200 g, were implanted with microdialysis probes in the amygdala (Am; N = 5) and dorsal hippocampus (DH; N = 6) and 5-HT levels were measured by electrochemical detection. Under basal conditions, 5-HT levels were approximately 50 and 230 fmol per 30 min sample, in the Am and DH, respectively. FEN (1O mg/kg, ip) produced a 3-4-fold increase in 5HT relesse in the Am, but not in the DH. Since the Am is mainly innervated by DR fibers while the DH receives 5-HT input chiefly from the median raphe (MR), the present results support the view that FEN selectively releases 5-HT from DR terminals.