Behavioral and biochemical correlates of the carbohydrate and tryptophan induced increase in brain serotonin were investigated in a series of 4 experiments. Experiment 1 was conducted to establish the nadir of brain tryptophan during the dark phase of the light cycle, Following a 16 hour fast, brains were removed, at 1600, 1800, 2000, 2.400, and 0400, hrs for tryptophan determination. Analyses indicated no differences in brain tryptophan throughout the dark period. The time course and peak concentrations of the carbohydrate and tryptophan induced increase in brain tryptophan and serotonin were determined in Experiment 2. Rats were fasted from 0030 to 1730 and then offered a control diet and injected with saline or 50 mg/kg tryptophan, or offered a high carbohydrate, protein-free meal and injected with saline. One hour after treatment and hourly for the next 3 hours, brains were obtained for analysis of tryptophan and serotonin. Tryptophan injected rats exhibited a peak in brain tryptophan at 1 hour post injection and a fall in tryptophan to control levels by 2 hours. Carbohydrate fed animals exhibited an increase in brain tryptophan at all times observed. Elevated brain serotonin was found in both tryptophan and carbohydrate treated animals. Experiment 3 was conducted to establish a behavioral correlate of brain serotonin. Behaviors investigated included: latency to step-down and explore a novel chamber and acquisition and extinction of a passive avoidance response. Animals were fed ad libitum, and 1 hour (1700) prior to behavioral testing injected with saline or 50 mg/kg tryptophan. Animals did not differ on measures of passive avoidance acquisition or extinction. However, tryptophan injected animals were found to exhibit a longer latency to step-down and explore a novel chamber than controls. In Experiment 4, plasma corticosterone, latency to step-down, rearing, urination, and defecation in a novel chamber were assessed. Animals were fasted from 2400 to 1700 and injected and fed as in Experiment 2. One and 2 hours following treatment, behaviors were observed. Thereafter, brains were removed for determination of tryptophan and serotonin and blood obtained for plasma corticosterone analysis. In tryptophan administered rats, brain tryptophan was observed to peak at 1 hour post injection and to remain higher than controls at 2 hours post injection. Carbohydrate fed rats were found to exhibit higher levels of brain tryptophan than control animals at both times assayed. Brain serotonin was found to peak in tryptophan treated rats at 1 hour post injection and to remain elevated at 2 hours. No changes in brain serotonin were revealed in carbohydrate fed animals. No group differences were observed for any of the behavioral measures taken. However, increased plasma corticosterone was found in rats fed the high carbohydrate meal. These data revealed that injection of tryptophan resulted in an increased latency to step-down and explore a novel chamber when animals were fed ab libitum, whereas carbohydrate ingestion resulted in an increase in plasma corticosterone with no effect on behavior. Confirmation that serotonin mediated these biochemical and behavioral changes awaits further research. / Land and Food Systems, Faculty of / Graduate

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Veronika Váchalová Supervisor: Prof. PharmDr. František Štaud, Ph.D. Consultant: Mgr. Rona Karahoda Title of diploma thesis: The influence of antidepressants on serotonin homeostasis in placenta Depression is a serious mental disorder affecting 10-20% of women during pregnancy. Up to 10% of these pregnant women are prescribed antidepressants (ADs), most frequently from the class of selective serotonin (5-HT) reuptake inhibitors (SSRIs). While the safety of this treatment is questionable due to reported impaired pregnancy/fetal outcomes, understanding of potential mechanistic causes is still lacking. During pregnancy, 5-HT is important for normal placental function and proper fetal development and programming. 5-HT homeostasis in the placenta is maintained via the 5-HT transporter (SERT/SLC6A4) on the apical side and the recently characterized organic cation transporter 3 (OCT3/SLC22A3) on the basal side of trophoblast. These transporters take up 5-HT from the maternal and fetal circulations, respectively into the syncytiotrophoblast (STB) where it is degraded by monoamine oxidase-A (MAO-A). As all ADs interfere with the 5-HT system it is important to study their potential interactions in the...

Thesis (M.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The amount o serotonin, one of the biologically active amines, was determined in selected species of non-mammalian vertebrates - the dogfish Mustelus canis, the tautog Tautoga onitis, the turtle Pseudymys scripta elegans, and the chicken Gellus gallus. The extraction procedure employed was highly sensitive and specific. Contaminating indoles which occur naturally in tissues were removed before extraction by shaking with diethyl ether and adjusting the pH. Serotonin was then extracted with butanol from an alkaline, sodium chloride-saturated solution and re-extracted back into dilute acid. It was identified on a Farrand spectrophotofluorometer by its characteristic activation activation peak at 305 mu and fluorescence peak at 550 mu, and the amount present was determined. The range in chicken whole blood was found to be 10.3-19.4 ug. per ml. Under the conditions of the experiment, the major portion of chicken blood serotonin could not be shown to be contained in the thrombocytes. The range of serotonin in turtle whole blood was found to be .228-1.32 ug. per ml. Serotonin could not be demonstrated in the tautog or the dogfish. / 2031-01-01

Muscle, hypodermis and gastrointestinal epithelium from adult female Ascaris lumricoides var. summ were found to contain serotonin based upon glyoxylic acid induced histofluorescence and indirect immunolabeling with an anti-serotonin monoclonal antibody conjugated to protein A-colloidal gold.

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

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